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Showing posts with label mechanic. Show all posts
Showing posts with label mechanic. Show all posts

Recharging a Vehicle's Air Conditioning System

Have you ever been in a car during the hot summer and turned the AC on just to find that it never seems to chill the air? Sometimes, with age, a vehicles air conditioning system needs to get a boost. Here is how you can do it yourself.

Air conditioning systems in vehicles operate at high pressures. A failure to properly service the AC system can lead to injury. These instructions are intended to be used as advice only, always follow the manufacturer's instructions when possible and proceed at your own risk.

Instructions with photos submitted by Andrew Schenk

A Full AC System is a Cold AC System
Most AC system problems can be traced to one or more of three likely candidates:
  1. Low refrigerant level due to age
  2. Low refrigerant level due to leak
  3. Bad AC compressor
If your car's air used to blow cold and very gradually over the years has had diminishing effect, then your car probably falls into the first category and just needs a refrigerant refresh. However, if it seems you have to recharge the AC system annually, there is a leak in the system that should be repaired. If your car's AC compressor is bad, no amount of refrigerant will help, you are in for some costly repairs.

Since anything beyond the first category is beyond most backyard mechanic's abilities, and due to the inherent dangers of novices working with AC systems, we will stick with a simple recharging of the AC system. If a simple recharge does not fix your AC problem, then take it to a shop that is properly equipped to service AC systems.

Which Type of Refrigerant?
If your vehicle was made prior to 1994 its AC system probably uses R12 refrigerant (commonly called Freon-12). R12 was banned due to its damaging effect on the ozone layer. Later vehicles use R134a refrigerant which is CFC free and does not harm the environment as the older R12 did. If your vehicle uses R12 refrigerant you will most likely not be able to legally recharge the system. You must be EPA certified to handle R12 refrigerant and, due to its lack of manufacturing, R12 is extremely expensive. Not all is lost, however, as there are R134a retrofitting conversion kits. These kits are not usually cheap as they replace most of the AC system, but will allow you to keep your cold air.

If your vehicle takes the common R134a refrigerant, then you can recharge the system yourself. You will need to buy a couple of things from an auto parts store:
  • One or more cans of R134a refrigerant
  • A recharge kit
  • (Optional but highly recommended) a recharge kit with a pressure gauge

When recharging the AC system, you need to make sure the system has the correct pressure; too low and the AC compressor may not run, too high and the can of refrigerant you are using to recharge the system can explode in your hand! To take the guesswork out of how much refrigerant to put into your system it isn’t a bad idea to get a Smart Charger that costs about $40.

How the AC System in Your Car Works
Here is a summary of how a vehicle AC system works.
The Compressor is the heart of the AC system. It compresses and pumps refrigerant that is in its gas form. The compressor is driven by the car's drive Belt but also has a Clutch to disengage if the compressor is not needed even when the engine (and belt) is running. You can sometimes hear an audible click coming from the front of your car when it is running (especially when idling), this noise is probably the clutch activating the AC compressor. The pressurized gas refrigerant is pumped to...
The Condenser, I component very similar to the car's cooling system radiator. In fact, in most vehicles, the condenser is located directly in front of the radiator. The gas refrigerant expels its heat in the condenser and turns into liquid refrigerant by the time it reaches the bottom of the condenser. The liquid refrigerant is now pressurized as it travels towards...
The Evaporator. The evaporator is very similar to the condenser. The liquid refrigerant is warmed by the air in the car and boils (refrigerant has a very low boiling temperature). As the refrigerant turns into a gas, it sucks heat from the car's cabin, cooling it in the process. The evaporator also acts as a dehumidifier, thus on humid days when a vehicle's AC has been running, you will often find water dripping from under the passenger side of the vehicle. This is condensation and is perfectly normal.
An Accumulator is found on many AC systems. Its primary function is to store liquid refrigerant and make sure only gas refrigerant gets to the compressor. An AC compressor is designed to compress gas, not liquid, so if too much liquid refrigerant gets to the compressor, it may be damaged.

Instructions
1. Find Your Low Pressure AC Valve. Every AC system has a low pressure and high pressure side. The low pressure valve will be on the hose that goes from the accumulator or evaporator to the compressor. The high pressure valve will be on the hose that goes from the compressor to the condenser or the condenser to the evaporator. The low side valve is the blue cap in the picture. Follow the instructions that come with the smart charger for hooking it up to the proper valve. In this case, the smart charger's valve won’t fit in the high pressure AC valve, so if it isn’t fitting right, you’re messing with the wrong hose! (Fig. A)
2. Install the Included AAA Batteries into the smart charger as shown. (Fig. B)
3. Start the Vehicle and Turn the AC to Max. It also isn’t a bad idea to roll down the windows so the compressor won’t shut off.
4. Once the Vehicle is Running and the smart charger is on, hook the blue hose of the smart charger to the low pressure valve. Press and hold the black button for a second or two and then release. The smart Charger will now diagnose your AC system. Consult the instructions that come with it for what to do if certain lights come on. (Fig. C)
5. If the White “Low Charge” Light Illuminates after diagnosing the system, shake a can of refrigerant and while the car is still running and the AC is still on, screw the can into the base of the smart charger. (Fig. D)
NOTE: MAKE SURE NOT TO TIP CAN UPSIDE DOWN, refrigerant will leak out. You should wear gloves and eye protection as refrigerant can cause frost bite in seconds.

6. Once the Can is Attached, squeeze black trigger for 15 seconds and then release to rediagnose the system.
7. Periodically Check the Vents to feel if the air is getting cooler.
8. If After the First Can of Refrigerant, the air isn’t any cooler, consider consulting a professional. It should take about 1 minute to empty a 12 oz can of refrigerant.

Summary
  1. Find the valve on the LOW pressure side of your AC system
  2. Turn on your car and set the AC to MAX
  3. Attach the smart charger to the LOW pressure valve
  4. Press the black button on the smart charger to diagnose the AC system
  5. If the system is low, screw a bottle of refrigerant into the smart charger
  6. Hold the black button for 15 seconds, then release to diagnose the AC system; repeat until the AC system has a proper charge

Conclusion
Although repairing a car's AC system is probably far out of the scope of the DIY, he or she can recharge a system low on refrigerant. It would be wise to purchase some sort of charging kit that has either a digital or analogue gauge to prevent over charging the system. If you are still having problems, or find that you need to recharge the system frequently, then take the car into a shop equipped to work on AC systems. They can add dye to the refrigerant to help find any leaks and fix any other problems.

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Replacing Spark Plugs

To keep your car's engine running efficiently, the spark plugs and, if necessary, spark plug wires, should be changed at their maintenance interval. Old and worn out spark plugs lead to weak combustion which robs your car of power and fuel efficiency. Depending on what vehicle you drive, doing a spark plug job can be anywhere from easy to difficult.

Always follow the factory recommended maintenance interval found in your owner's manual when servicing your vehicle.

Instructions and photos courtesy of Andrew and Peter.

The Patient
The car featured in this spark plug how-to article is a 1999 Nissan Altima, the same one as can be seen here. This car has four spark plugs located on the top of the engine, making this one of the easiest spark plug jobs you will ever find!

Before you begin you will need to gather the tools and parts necessary to change the spark plugs. In this case we will need:
  • Four spark plugs for this vehicle (OEM/NGK recommended)
  • Dialectic Grease
  • Anti-Seize Compound
  • Spark Plug socket (a spark plug socket has special padding to protect the porcelain section of the spark plug)
  • Ratchet with long (at least 6") extension
  • Spark Plug gap tool (wire loop type recommended for platinum plugs)

1. Clean the Area around the spark plugs so that when the plugs are removed no dirt or debris will get into the engine.
2. Pull the Spark Plug Wire Boot straight up and off the first spark plug. You may have to twist it back and forth while pulling up to free the boot from the end of the spark plug. Always make sure that you pull on the boot and NOT the wire! (Fig. A)
3. Insert the Spark Plug Socket and remove the spark plug. (Fig. B)
4. Clean the Spark Plug Wire Boot with a clean rag. (Fig. C)5. Gap the New Spark Plug to the specified gap (0.042").
Note on gapping spark plugs: If you have "Double Platinum" type spark plugs you need to be very careful when gapping them. You can very easily break the platinum tip off the ground electrode!

6. Apply Anti-Seize Compound to the spark plug threads. This will keep the spark plugs from getting stuck in the engine. (Fig. D)
7. Install the New Spark Plug. Start by fully seating the spark plug into the spark plug socket, this way the socket will hold the spark plug and prevent it from falling and bending the ground electrode. Once it starts to thread properly, tighten it to its proper torque rating (between 14 and 22 ft. lbs.). If you do not have access to a torque wrench, tighten the spark plug to where you have to start putting a little bit of force into the wrench, then another quarter to half turn. It should not be over tightened and 14-22 ft. lbs does not require much effort when using a ratchet. (Fig. E)
8. Apply Dialectic Grease to the spark plug wire boot. (Fig. F)9. Install the Wire Boot by pressing it firmly down onto the spark plug.
10. Continue Until All the Spark Plugs Have Been Changed. Work on one plug at a time to avoid mixing up the spark plug wires.

Summary
  1. Remove spark plug wire boot from spark plug.
  2. Remove old spark plug.
  3. Gap new spark plug.
  4. Apply anti-seize to spark plug threads.
  5. Install new spark plug.
  6. Apply dialectic grease to spark plug wire boot.
  7. Install spark plug wire boot.

Conclusion
The reason replacing spark plugs on this car is so easy is due to their easy accessibility. On other vehicles, especially 'V' type engines (i.e. V6, V8) the spark plugs can be difficult to reach. If you have a V6 front wheel drive car you will be able to reach 3 of the 6 plugs without a problem, but the other 3 will be hard.
Changing spark plugs is one of those iconic jobs that comes to mind when a "tune-up" is mentioned. In this case it was a quick, easy, and inexpensive job and was worth doing.


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Replacing Dashboard Lights

Whether you call them dashboard lights, instrument cluster lights or gauge lights, it can be a real pain when they burn out and have to be replaced. I had the light that illuminated the fuel gauge burn out so I decided to replace all the lights, but with a twist. I replaced the stock incandescent bulbs with LED bulbs that will last virtually forever.

The dashboard, instrument cluster and several other important components can easily be broken or damaged during this procedure if you are not careful. Proceed at your own risk.

Why LEDs?
Perhaps before I get into the step-by-step instructions for replacing the dash lights, I should explain why I chose to use LED bulbs. LEDs (Light Emitting Diodes) last much, much longer than traditional incandescent bulbs, they use less energy, and they are generally brighter. On the downside, their initial price is higher, their light typically shines in a narrow spot light beam, and they are much harder to find.

The first step in picking replacement dash bulbs is to find out what type of bulb you need. You can go to an auto parts store and they will be able to look it up for you, but chances are they will only have the stock replacement bulbs. You can also use the online Sylvania bulb replacement guide by following the link under the "Favorite Automobile Sites" at the bottom of this website.
To combat the downside of price and availability, I turned to eBay to find replacement LED bulbs. After searching and researching, I decided to get some bright white inverted cone LEDs. The inverted cone design helps spread the light of the LED to give a more uniform illumination.

If you are replacing the light bulbs behind your dashboard and do not wish to use LEDs, I would recommend two things: first, replace all the bulbs, even if only one has burned out. Second, you can get "long life" incandescent bulbs (usually marked by the item # and then 'LL'). For example, my truck uses bulb# 194 type light bulbs. You can replace these with 194LL (long life) or LEDs designed to be plug-n-play with 194 bulbs.

Instructions
1. Remove the Radio Bezel by removing the two 7mm screws and then pull the bezel out. (Fig. A & B)
2. Remove the Four Screws Holding the Kick Panel, these are also 7mm screws. Two of these screws are under the hood release latch, remove these screws, let the hood release latch hang and fully remove the plastic kick panel. (Fig. C)
3. The Kick Panel Metal Brace needs to be loosened. Loosen the bottom two 8mm screws and remove the remaining 8mm screws, then pull the metal brace out far enough to reach the bottom screws of the instrument cluster bezel (see next step). (Fig. D & E)
4. Loosen the Instrument Cluster Bezel by first removing the bottom two 7mm screws (see Fig. E) and then the top three 7mm screws. (Fig. F)
5. Tilt the Steering Wheel and Transmission Selector Out of the Way. If you have tilt steering, move the steering wheel to its lowest position. Then block the wheels, put your key into the ignition and turn it to ON (not START), press the brake pedal and move the gear selector to its lowest position, '1'. (Fig. G)
6. Remove the Instrument Cluster Bezel by prying around its perimeter until all the plastic tabs have disengaged and the bezel can be pulled out. The bezel will still be attached to the truck via the headlights selector and dimmer switch. You do not need to remove these. Carefully pull the bezel out and over the steering wheel and lay it to the side, out of the way. (Fig. H & I)
7. Remove the Instrument Cluster Screws, there are four of them and they are 7mm. (Fig. J)
8. Pull the Gauge Cluster Out and to the right. Pull it out far enough to reach behind the cluster to disengage the three electrical connectors (as seen in Fig. L). The cluster will still be attached to the truck via the speedometer cable. You can remove this cable if you wish, but it is not necessary. To remove the speedometer cable, disconnect it where it meets the transmission. (Fig. K)
9. Twist the Black Caps to remove the bulb sockets. With the bulb socket out, pull the bulb out of the socket. Install your new bulb. Figure M shows the stock incandescent bulbs above and two LED bulbs below. You can see which bulb was burned out and that one was well on its way to burning out. (Fig. L & M)

NOTE: LED bulbs have to be installed with the positive and negative in the right direction otherwise they will not work. The following steps will detail how I was able to make sure all the bulbs were installed correctly.

10. Reattach the Electrical Connectors, but leave the gauge cluster out far enough to where you can access the back panel and the bulb sockets. If you are working in a light area, use a cloth to drape over the gauge cluster, turn the headlights on to check to make sure each of the six bulbs are functioning. If you install LEDs and a bulb does not work, unscrew that bulb's socket, remove the bulb and install it in reverse to get the correct polarity. When all the bulbs work, reinstall everything by following these instructions in reverse. (Fig. N)

Summary
  1. Pull the radio bezel out.
  2. Remove the kick panel.
  3. Loosen and pull the kick panel metal brace out.
  4. Drop the steering wheel to its lowest position (if equipped with tilt steering) and put the transmission into '1' (if automatic).
  5. Remove the instrument cluster bezel.
  6. Remove the gauge cluster.
  7. Replace the bulbs.
  8. Test the bulbs.
  9. Reinstall in reverse.

Conclusion
There are many options when working with gauges and gauge lights. I know a lot of people like to get custom gauges or change the color of their dash lights, but I had decided to save my money and, besides switching to LED bulbs, remain stock. However, not everything always works to plan. I was expecting the lights to remain the stock green, but due to the difference of LED white light versus the more natural yellow light of incandescent bulbs reacting with the colored film covering the gauges, the lights turned from green to blue. This was an unexpected side effect, but not necessarily a bad one, after all, my basic color scheme for my truck is white and blue.
The whole process was not as difficult as I thought it would be. With good directions, it took about an hour, and that included the time it took me to take pictures along the way.

And now, the before and after photo, notice you cannot see the fuel gauge in the before(top) shot (sorry for the poor quality):

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Swapping a 2-Piece Drive Shaft for a 1-Piece in a 1983-1997 Ford Ranger

Extended cab Ford Rangers* up through the 1997 model year use a 2-piece drive shaft to connect the transmission to rear axle. In 1998, Ford replaced the 2-piece shaft with a single shaft of either steel or aluminum.

*1994 and newer Mazda B-Series trucks are mechanically identical to Ford Ranger, therefore driveshafts are interchangeable and the procedure would be the same.

Anatomy of a Drive Shaft
Before I get started, perhaps it would help if I did a quick explanation of the parts of the drive shaft.This diagram shows the drive shafts arranged so that the front is on the right and the rear of the shafts are on the left. The slip yoke slides into the transmission on two wheel drive vehicles. 4x4 vehicles have a flange that bolts onto the transfer case. The U-joints allow the drive shaft to flex and move as the vehicle's suspension travels up and down. The rear flange bolts onto the pinion flange which comes out of the rear differential (the large "pumpkin" shaped thing you see on the rear axles of trucks). The carrier bearing connects the front and aft shafts on 2-piece drive shafts.

Why and When Would You Want to Swap the Factory 2-Piece Drive Shaft for a 1-Piece?
In stock form, the 2-piece drive shaft functions without problem, however there is an extra u-joint and carrier bearing which adds to the drive line maintenance.

The 2-piece's main shortcoming is that it does not lend itself to non-stock suspension heights. Adding even a slight suspension lift kit or lowering the suspension will cause the drive shaft to vibrate at certain speeds which is not only incredibly annoying, it can also lead to premature u-joint and carrier bearing failure. This drawing I made illustrates the cause of the vibration:As you can see in the picture, in stock form, the line between the transmission and the rear differential (hidden behind the rear tire in the picture) is straight, as indicated by the red line. When the vehicle's suspension is raised, the transmission (large silver object in picture) and carrier bearing (light blue object that connects the fore shaft and rear shaft) are also raised because they are connected to the vehicle's frame. This takes the driveline out from the straight line and causes the u-joints on the drive shaft to operate at extreme angles. This in turn causes a vibration that usually occurs at very slow speeds and highway speeds.

There are two possible corrections for this problem.
1. Lower the carrier bearing. By dropping the carrier bearing, you can help restore the proper angle of the drive line. However, it is impossible to completely remove the vibration because the front and back of the 2-piece drive shaft will never be in phase with each other.
2. Replace the 2-piece drive shaft with a single piece. You have two options within this option: get a custom drive shaft made at high expense, or find a used drive shaft from a newer Ranger, usually at a very reasonable rate.

It may seem like #1 would be easier, but swapping out the entire drive shaft is no more work. I have done both with my truck and would highly recommend skipping the hassle you will face trying to fine tune the carrier bearing height and go straight for the drive shaft swap.

Which Drive Shaft Can I Use?
All 1998 and newer Rangers* with the extended cab (sometimes called supercab) come with a single piece driveshaft, however, you will need to get the right one. The easiest way is to match up the specifications of your truck with the donor truck. These criteria will need to be fulfilled in order to get a good match:
  • Same drive train: 4x4 or 4x2?
  • Same transmission type: Automatic transmission or manual?
If your truck is a 4x4, it will not matter what type of transmission the donor truck has because the driveshaft attaches to the transfer case.

Note: 1983-1989 Rangers use a smaller flange on the rear axle. You will need to swap the rear u-joint section with one from the front of the shaft.

Note: If you get a drive shaft from a 4x4 with the aluminum drive shaft, it will have a larger transfer case flange and you will either need to swap in a smaller u-joint unit from the rear of the shaft (the exact opposite of what you need to do in the 1983-1989 note) or swap the flange on the transfer case.

You may ask where you can find a suitable drive shaft for the swap. Your best bet is a junkyard. You may also have luck searching online used car part sites (e-junkyards), online auction sites, or classified sections of online Ranger forums (there are several good ones). I purchased mine off a fellow member of a Ranger forum at a decent price.

There are two types of drive shafts available: steel and aluminum. I first thought all the shafts from 4x4s were steel and all from 4x2s were aluminum, but that is not entirely true, some of the newer 4x4s have aluminum shafts and I have heard of a few rare instances of 4x2s with steel shafts. It really boils down to availability and personal preference.

What Else Will I Need To Swap Drive Shafts?
The only tool you will need to swap the drive shafts is a 12mm 12-point socket and ratchet. Unfortunately, that is not all that needs to be done. Remember that carrier bearing on your old drive shaft? It is attached to a frame cross member. That cross member must be removed too, and that is no easy task.
So, besides the socket for the drive shaft you will need an angle grinder with metal cutting/grinding wheel, a punch and heavy hammer.

Before You Remove the Drive Shaft
You will want to set the parking brake and block the wheels before removing the drive shaft. Having the transmission in Park will do nothing once the drive shaft is removed since the transmission will no longer be attached to the wheels.

Removing the Carrier Bearing Cross Member
The first step is perhaps the hardest: freeing the frame cross member that supports the carrier bearing. The cross member is held onto the frame with two large rivets on either end. In addition to the rivets, each end of the cross member has a tab that sticks through a small slot in the side of the frame.Here you see a cross section of the frame where the cross member is riveted on. The yellow piece is the frame rail, the green section is the cross member, and the red part is a rivet. The green arrow points to the cross member tab that sticks through a slot cut in the frame. The red arrow points out the head of the rivet.

Start by grinding the rivet head off. Hold the grinder so that the sparks fly away from the vehicle since the gas tank is nearby. If you need to, improvise a spark shield out of cardboard or some other suitable material to place between where you are grinding and the gas tank.

When the rivet head has been completely ground off you need to take your metal punch, a stout metal bar, or some other suitable tool and use a heavy hammer to punch the rivet up and out of the hole. Repeat for the second rivet on the side you are working on, then move to the other side of the cross member and remove those two rivets.

On 4x4 models, you will also need to remove the gas tank skid plate.

With the rivets removed, you will need to remove the tabs from the ends of the cross member. I used the grinder to remove as much of the metal as I could from end of the tab protruding through the frame, then used a chisel and hammer and pounded the rest of the tab back, bending it and getting it free from the slot in the frame rail. Alternatively, you could cut the cross member in two and then slide each end out.

When the cross member is free it should just be resting on the inside of the frame. Our attention now moves to the carrier bearing. It is mounted onto the cross member by two bolts. Remove those bolts.

Position a jack stand under the carrier bearing because once we remove the cross member, the bearing will not be supported. You will have to rotate the cross member in order to get it completely free and off the vehicle. Exhaust and fuel system components may be in the way. With a little work, the cross member should come out. With the cross member out, support the carrier bearing with the jack stand.

Note: This cross member's only function is to support the carrier bearing, therefore it is safe to completely remove the cross member and discard it.

Removing the Drive Shaft
The dive shaft is attached at the rear differential flange by bolts. You will need a 12-point 12mm socket or wrench to remove the bolts. Once all the bolts are removed, the rear of the driveshaft should come loose. If it is still stuck on the flange (which it very well might be), try giving it a few light blows with a rubber mallet. Just be careful to not damage the mounting surface on the differential side.

When the rear of the drive shaft is loose, slowly pull the front of the drive shaft (the slip yoke) out of the transmission (4x2 models) or unbolt the front flange from the transfer case (4x4 models). The old 2-piece drive shaft should now be free from the vehicle!

Installing the "New" Drive Shaft
Before you install the new shaft, lubricate the teeth in the slip yoke with a little grease. Also notice that there is one tooth missing, this is for indexing purposes. If you look at the transmission you will see how the slip yoke (front of the driveshaft) needs to be orientated to slip into the transmission. Now is also a good time to inspect the transmission seal and replace if needed (if it is leaking transmission fluid out of the output shaft - where you will be inserting the drive shaft).

Orientate the drive shaft slip yoke with the transmission and insert it. If it does not want to go in, slowly turn the slip yoke until the indexing teeth match up. Slide the drive shaft slip yoke in slowly until you can bring the rear of the drive shaft up and rest it against the differential flange.

With the rear flanges lined up, reinstall the 12mm 12-point bolts. Tighten the bolts a little at a time to even out the pressure, like when you tighten wheel lug nuts. Fully tighten them to 85 ft. lbs.

Release the parking brake and remove the wheel blocks.

And there you have it, a nice solid 1-piece drive shaft!

Summary
  1. Remove the rivets holding the cross member.
  2. Detach the carrier bearing from the cross member.
  3. Remove the cross member.
  4. Remove the 2-piece drive shaft.
  5. Install the new drive shaft.

Some Additional Notes:
I can also say that there were no clearance issues for me using an aluminum drive shaft in a 2wd truck. Some people say you may have to modify the floor boards or lower the transmission to accommodate the aluminum shaft's larger diameter, but that is not true.

Apart from removing the carrier bearing cross member, this was an easy and affordable swap that has completely eliminated the drive line vibrations I was having after lifting the truck.

Relevant Sites
Here are some external links to sites with information relevant to this article. I would like to thank The Ranger Station for these great articles!

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Replace a Thermostat

A car's thermostat controls the flow of coolant to keep the engine in its prime operating temperature. Thermostats can become stuck in either the open or closed position. In either case, it will need to be replaced.

The following instructions are based off a thermostat I replaced on my 1996 4.0L Ford Ranger. Other vehicles will be similar but these instructions may have to be slightly altered for them.

Too Hot, Too Cold, or Just Right?
I noticed the temperature gauge needle never got off the very bottom mark unless I drove on the interstate for over 20 minutes. Even then, it barely got above the cold mark. I knew either the thermostat or the temperature sending unit were bad. Since I was flushing my cooling system, I decided to go ahead and replace the thermostat to see if it would fix my problem. Thermostats are inexpensive (around $5 for most domestic vehicles), so well worth the price to "throw parts" at a problem to see if the problem can be fixed.

Troubleshooting the Thermostat
A working thermostat will let the engine get into its normal operating temperature within a few minutes of running and keep it there. You will also be able to get heat from the HVAC controls relatively quickly. If your car has a problem with any of these, the thermostat may need to be changed.

The thermostat may be stuck open if...
  • The engine takes a long time to heat up - indicated by either the temperature gauge not wanting to leave the "C" or "Cold" mark. (Check to make sure the Temperature Sending Unit is working properly, as this may cause an incorrect temperature gauge reading).
  • It takes a long time to get heat from the HVAC.
  • The upper radiator hose never gets hot, even after the vehicle has been driven for several miles.
The thermostat may be stuck closed if...
  • The engine overheats after a consistent amount of time driving, shortly after starting the engine and no leakage can be found from the radiator, hoses, head gasket, or heater core.

Tools and Materials
  • 10mm socket (1/4" drive)
  • 1/4" ratchet (there is not enough clearance for a 3/8" ratchet)
  • Small 1/4" extension
  • 10mm combination box-end and open-end wrench
  • New thermostat with gasket
  • 50/50 mix of coolant and water to top off the radiator if any spills out during operation

Changing the Thermostat
A good time to change the thermostat is when the cooling system is empty, like during a coolant system flush. It is possible to change the thermostat with a full cooling system but some coolant will leak out of the disconnected hoses.

Follow these photos and captions for the thermostat changing instructions on a 1996 4.0L Ford Ranger:

Locate the thermostat housing by following the upper radiator hose to where it connects with the engine block.


Here you can see the thermostat housing tucked away.


You will have an easier time accessing the thermostat by removing the throttle cable splash shield and disconnecting the electrical connector that goes into the air intake. You can also completely remove the air intake hose, but I opted not to.


You will need to remove these two 10mm bolts.


And there is one more underneath.


Here is the thermostat (red arrow). The blue arrow shows the Temperature Sending Unit which controls the temperature gauge. The TSU will always have one wire coming out of it. The green arrow shows the Temperature Sensor, this sensor tells the car's computer how hot the coolant is. This sensor will always have two or three wires coming out of it.


Remove any old gasket material from the hose side and engine side of the thermostat housing.


Here is the new thermostat with rubber gasket installed. Note how it is installed. The spring side should go towards the engine.

To finish: follow the steps in reverse.

Before it took a lot of driving to even move the temperature gauge needle on my truck, now the truck warms up quickly and stays in the normal temperature range like it should. This should help keep the engine running well, improve gas mileage, and keep emissions low.


Summary
  1. Locate the thermostat housing, it will always be at the end of the upper radiator hose where it connects to the engine block.
  2. Remove anything that is in the way, such as electrical connectors, splash shields, etc.
  3. Remove the thermostat housing bolts (3 10mm bolts on this particular engine).
  4. Pull the hose side of the thermostat housing away from the engine block and remove the old thermostat.
  5. Install the new thermostat.
  6. Reinstall the thermostat housing, bolts, and any other components you removed to access the thermostat.

An Easy Fix
Thermostats are usually very inexpensive and easy to change so I would almost consider them a routine maintenance item if the original one did not last almost 200,000 miles. Nevertheless, I would still recommend making a thermostat replacement part of you preventative maintenance schedule by changing the thermostat about every other time you flush your cooling system.

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Drum Brake Maintenance

The good thing about drum brakes is that they require little and seldom maintenance. Commonly, the brake shoes need to be replaced every 60,000 - 100,000 miles. I will show how to change the shoes and perform some other maintenance on drum brakes in this article.

These instructions, though intended for a general audience, are specific to a Ford Ranger with 10" drums. The drum brakes on your vehicle may be slightly different but should still be similar enough for this article to help. If you are not comfortable working on critical components, like the braking systems, you should probably let a qualified professional mechanic do the work for you.

If you are not familiar with drum brakes or would like to learn more about them I have a short article summarizing the history of drum brakes and a real brief description of how they work here.

Parts and Materials
1 Set of Brake Shoes
1 Drum Brake Hardware Kit
Brake Grease
Brake Spring Compressor Tool Pictured at Right
Brake Spring Plier Tool Pictured at Right
Left & Right Brake Adjuster Hardware Kits
Wheel Cylinders
Brake Drums
Brake Cleaner


TOOLS REQUIRED
Jack
Jack Stands
Appropriate Wrenches to remove wheels
Needle Nose Pliers
Brake Spring Compressor Tool
Brake Spring Pliers Tool
Vise Grips
2 Flat Head Screw Drivers
Catch pan
7/16 Brake Line Wrench (if replacing Wheel Cylinder)
1/2” Wrench/Socket (if replacing Wheel Cylinder)

Step-By-Step Instructions
1. Release the Parking Brake, loosen the lug nuts on the rear wheels, chock the front wheels, jack the rear axle up and place it on jack stands. Remove the rear wheels.

2. Remove the Drums. If they do not slide off you will have to retract the shoes. On the back side of the brake backing plate you will see a rectangular rubber plug near the bottom. Remove the plug and shine a light through the hole. You will see a wheel with teeth. Insert a flat head screw driver and rotate that wheel UP to retract the shoes.
This photo shows, from the inside, what you will be doing to retract the shoes. Circled in red is the rubber plug that needs to be removed. The green arrow shows the adjusting wheel. If the adjusting wheel does not turn, you may need to insert a second screw driver and depress the adjuster (the pivoting metal piece partially circled in red).

3. With the drums removed, you should see this:
Hopefully you will not see this:
Put both drums aside. You will need to work on one side at a time and use the other side as reference.

4. Place the Catch Pan Under the Brake Assembly and liberally spray the brakes with brake cleaner. Let air dry.

5. Remove the Shoe Retracting Springs (A), the Adjusting Cable eye (B) and the Anchor Pin Plate (C). If you bought the hardware kit, the springs can be disposed but keep the adjusting cable and anchor plate.
Remove the Parking Brake Strut which is the metal bar just below the Wheel Cylinder with a spring on one end. The Wheel Cylinder in the above photo is the large horizontal cylinder in the middle of the photo, directly below the springs and above the wheel lug nut stud.

6. Now the Shoe Retaining Springs and Pins need to be removed. There is one per shoe. These can be discarded if you purchased the hardware kit.

7. Remove the Adjusting Screw (A), the Adjusting Cable (if it was not completely removed in step 5) (B), the Lower Spring (C), and the Adjusting Pawl and Spring (D). The Lower Spring can be discarded if you purchased the hardware kit.
The Primary Shoe should be completely free - remove it. The Secondary Shoe will still be attached to the Parking Brake Cable via the Actuating Lever. Separate them.

8. Everything except the Wheel Cylinder should now be removed from the brake backing plate. Now is a good time to spray down the brake with brake cleaner one more time. Let it air dry, then clean it thoroughly with a rag. Spray it again if necessary.
This is also a good time to take all the hardware and parts that will be reused and clean them thoroughly. I would suggest putting all the parts to be discarded off to the side but do not discard them yet - just in case you need to reuse something.

This is a good time to replace the Wheel Cylinder if you need to. If not, skip ahead to step 9.
WC1. If your brake looks like this:
You definitely need to replace the Wheel Cylinder (referred to as WC from here on out). If you are not sure if the WC needs to be replaced, carefully pull back on the rubber seals. If brake fluid escapes, you should replace or overhaul the WC.

WC2. The WC is held on by two bolts and the brake line that go through the brake backing plate. Use a 7/16” brake wrench to loosen the brake line. Use a 1/2” wrench or ratchet to loosen the two bolts. If they are on too tight, spray the area with penetrating oil like PB Blaster. Now would be a good time to start cleaning the parts while the oil soaks in.

WC3. Remove the brake line fitting - it does not need to be pulled back from the WC. Remove the two bolts.

WC4. Pull the old WC out and clean the mating surface before installing the new WC. Place the new WC in the slot, install the two bolts, and then install the brake line. These need to be tightened down pretty good. Now is also a good time to loosen the bleed valve to make bleeding the brake easier.

It should now look like this:

9. At your work bench, remove the retaining clip (C) that holds the Secondary Brake Shoe (A) and the Parking Brake Actuating Lever (B) together. I found it very difficult to remove without destroying it. You should have a new one in your hardware kit, but my kit came with only one new retaining clip but an extra shoe retaining clip.

The old Brake Shoe can be discarded but we will be reusing the Actuating Lever.

10. Install the Actuating Lever and retaining clip on the new brake shoe. Then install the Parking Brake Cable to the Actuating Lever making sure it is installed the correct way (use the other brake as reference). Let the brake shoe and lever hang down for now.

11. Apply Brake Grease to the shoe backing plates. Make sure you get all of them.
Lubricate the threads of the threads of the Adjusting Screw with brake grease.


Refer to this Photo for the installation steps:
12. Position the Shoes, one at a time, on the backing plate. Insert the Shoe Retaining Pin from the back of the backing plate all the way through the shoe. Place a Retaining Spring over the pin, then use the Brake Spring Compressor Tool to install the Retaining Spring Cap (see the photo from step 6). This step can be very difficult by yourself because the brake shoe may not want to stay put while you try to install the retaining clip. Although not strictly necessary, I had a MUCH easier time performing this step with the brake spring tool. (PHOTO - A)

13. Install the Parking Brake Strut with one end in the slot in the primary shoe and the other end in the Actuating Lever - not the Secondary Shoe. Use the other brake for reference.
Make sure the Wheel Cylinder pushrods are in the proper slots in the brake shoes. (PHOTO - B)

14. Install the Adjusting Screw into the bottom of the Shoes in its appropriate slots. The long end of the screw should be facing the front of the vehicle (PHOTO - C). Install the Adjusting Pawl and spring (PHOTO - D) and then the lower Spring (PHOTO - E).

15. Now for the top of the brake. Install the Anchor Pin Plate (PHOTO - G) and the Cable Guide (PHOTO - F). The cable guide should fit flush against the shoe. One of mine did but the other one took a little filing to get it to seat properly.
Install the eye of the Adjusting Cable (PHOTO - H).

16. Install the Shoe Retracting Springs (PHOTOS - I & J). This is where the Spring Pliers really come in handy. Slip the hooked jaw of the plier over the spring hook and place the end of the other jaw in a hole on the top of the opposite brake shoe. Then squeeze the plier handles together and the spring should easily slip over the stud. This method is so much easier than trying to strong arm the springs into place using vice grips.

17. Finally, route the Adjusting Cable around the cable guide and connect the hook at the end to the Adjusting Pawl. The hook should attach from behind the Pawl, not over top of it. You can lift the pawl up to make installation easy.

18. Make sure everything is seated correctly including the Wheel Cylinder pushrods, Parking Brake Strut, and Adjusting Screw.

19. If you have new drums, install them. If you are reusing your old drums, either have them resurfaced or at least scrub any hard spots with fine emory cloth.

20. From behind the brake, use your screw driver to push DOWN on the adjusting screw until the shoes come into contact with the drum, then back the screw off. If you installed a new Wheel Cylinder, now is a good time to bleed the brake. Remember to top off the brake fluid. The brakes should self adjust when you apply the brakes while going in reverse.

21. Now repeat for the other side!

Summary
A "quick" version is below:
  1. Remove the drums from both wheels.
  2. Remove the old brake hardware.
  3. Remove the brake shoes.
  4. Install the parking brake actuator on the new shoe.
  5. Lubricate the shoe backing plates.
  6. Install the new shoes and shoe retaining clips.
  7. Install the parking brake strut.
  8. Install the adjusting screw.
  9. Install the anchor pin plate, cable guide, and cable eye loop.
  10. Install the shoe retracting springs.
  11. Connect the adjusting cable to the parking pawl.
  12. Install new drums or resurfaced old drums.
  13. Manually adjust the shoes until they touch the drum, then back them off a bit.

Maintenance That is Often Avoided
Working on drum brakes often seems too complicated to the novice DIY mechanic. They may hear horror stories of the complexity of the brakes and how somebody could not reinstall a spring. Honestly, drum brakes are not too hard. The key is to work on one side at a time so you can use the other side as a reference. If you hesitate at the notion of working on your own drum brakes but don't even flinch at the thought of working on disc brakes, you have nothing to worry about. Just image drum brakes as jigsaw puzzles with only a few parts!

Relevant Sites
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Replace an Accessory Drive Belt

Serpentine and Accessory belts are considered maintenance items because, with time and age, they wear out and need to be replaced. Is replacing a belt an easy task or are you better off letting a professional do it?

These instructions were made while replacing an air conditioning condenser belt on a 1999 Nissan Altima. Vehicles with multiple belts will probably be similar.

How Many Belts?
I recently had the pleasure of helping my brother replace the air conditioning belt on his 1999 Nissan Altima. Most vehicles sold today either have one serpentine belt that weaves its way around all the pulleys, or two separate belts. In the case of the Altima, the main belt drives the power steering, alternator, and water pump. A secondary belt drives the air conditioning compressor.

As a side note, reading the belt diagram or following the route of the belt is an easy way to identify these automotive components.

This diagram is general representation of a two belt system. The red line represents the main belt and the blue line represents the secondary belt.

Luckily for us, the AC belt was the outer-most belt. This meant we did not have to take the main belt off in order to change the secondary belt.

Whenever changing a belt, you will always have to relieve the belt tension. Some systems use a spring loaded automatically adjusting self tensioner that must be rotated to relieve the tension. On the Altima, the belt tension is manually adjusted by a bolt. The belt tensioner pulley is attached to a pin that can slide up or down in a bracket. Here are the steps taken to replace the belt:
1. Remove the Splash Shield from behind the passenger's side front wheel. There will be a few screws or bolts holding the plastic splash shield in place. Once the shield is removed you will have clear access to the belt.
2. Remove the Bolt and washer from the belt tensioner pulley (blue arrow)
3. Remove the Adjusting Bolt (red arrow)
4. Note How the Pulley, Pin, Bracket, and Adjusting Bolt go together.
5. Remove the Pulley and inspect it. Lubricate or replace if needed.
6. Remove the Old Belt while taking note of how it is routed.
7. Reinstall the the Pulley Assembly but do not tighten the bolts yet. The pulley should freely slide up and down in the bracket.
8. Install the New Belt. Move the pulley to its highest point in order to get the belt on. It may still be a tight fit.
9. Make Sure the Belt is Properly Seated in each of the pulleys - the crankcase (engine), AC compressor, and tensioner.
10. Tighten the Pulley Bolt (blue arrow), then tighten the adjusting bolt to 26 ft. lbs.
11. Check to Belt's Tightness. To check, measure the amount the belt will deflect when you press against it at a point half way between two pulleys. The amount of deflection should be about 1/4" If it deflects more than that, tighten the adjusting bolt. If it does not deflect, then it is too tight and you need to loosen the adjusting bolt.
It is also a good idea to clean the the pulleys when you have the belt off. You should also check each pulley to make sure it spins freely (with the exception of the crankcase pulley). If any of the pulleys grind or resist spinning, try cleaning them or replacing them.

The Quick Version
  1. Remove the passenger's side front wheel splash shield.
  2. Remove the main bolt and adjusting bolt from the belt tensioner.
  3. Remove the belt tensioner pulley.
  4. Remove the old belt.
  5. Reinstall the tensioner pulley assembly.
  6. Install the new belt.
  7. Tighten the tensioner adjusting bolt to 26 ft. lbs. or until the belt deflects about 1/4"

Not Too Hard
No special tools were required to replace the belt and we did not even have to raise the front of the vehicle up. The only time we had any kind of trouble was getting the tensioner adjusting bolt to move. We found years of sediment compacted in the threads of the bolt that made it difficult to remove.


Relevant Sites
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