I am Lance, Mobile Air. Today we're going to diagnose a/c system on a 1994 Ford F-series truck. We're going to need minimum of a gauge set, so you can tell the charge amount in the system. You're also gonna need a vacuum pump to evacuate any air and moisture in the system, a recovery unit that the system still has a charge with the recovery tank. A charging scale, a thermometer and the refrigerant. First you wanna diagnose in the situation with this truck. Next we gonna hook up the gauge set. As you can see, we've got no charge in the system. So this system has been completely drained , either due to a leak or the system has been recovered. Next up, we're gonna do is, we're going to disconnect the ground of the battery. Certainly 70,000 miles on it. So we'll start by removing the clutch cover off the compressor to see the if there is an oil leak at the shaft seal. And as you can see, there is oil inside of this wound pressure plate, here. There's also oil and dirt build-up around the shaft seal which is an apparent shaft seal leak. Also you want to do another visual inspection to make sure there's no other apparent leaks or shaving of the hoses. After everything else looks good, start by removing the compressor. Remove the clutch wire. Remove the hose assembly from near the compressor. Let's be very careful not to get any dirt in the hoses.
Next, we gonna remove the 4 bolts holding the compressor to the motor mount. I'm looking inside the compressor to see, if you can see any metal shavings on the discharge port. To see if the compressor came apart internally. And it looks good.
Next we gonna remove the accumulator and the expansion device which in this case happens to be an orifice tube, located right here. So we're gonna start with taking off the plug wire to the switch, cycling switch. I'm removing the cycling switch. This will go on the new accumulator.
This one is a backup wrench for removing any of the lines. Again you wanna be careful that you don't get debris inside of the hoses. Now we're gonna remove the orifice tube. First you must take off the safety clips, retaining clip. With the help of this tool we have to remove the Ford spring lock. Here is a pair of pliers or they make a special tool to remove the orifice tube. Inspect the orifice tube for any excessive metal shavings or the system might need to be flushed. Orifice tubes are color-coded with different sizes with the orifices inside. This is the device used to release the spring in the Ford spring leaf fittings. This is the removal of the accumulator with the brackets attached. When removing, we always must remember to start with disconnecting the negative on the battery, removing all the components of air conditioning system, making sure that you follow the steps while reinstalling the new components.
Install AC Compressor System - Part 2:
In this kit it should have a new accumulator and O-ring and seal kit, refrigerant oil and expansion device, in this case an orifice tube. And of course a new compressor. We want to compare the old parts to new parts, to make sure that you've got everything correct. Some other things to look for: make sure that your clutch has the same diameter and has the same hose ports. Also that the manifold ports are in the same position.
Next, notice that this orifice tube is red in color as is the new one. And finally the accumulator. Look to see to make sure that the hose ports and mounting brackets are correct. To fill the proper amount of refrigeration oil, you wanna take the cap off the rear. You're gonna need some sort of measuring device. Make sure everything is clean before you empty the oil into the measuring device. Put all the oil emptied out of the compressor, now you gonna wanna add the capacity that's recommended by the manufacturer in this case it's seven ounces, a bag of oil.
After the oil has been put back in the compressor, you wanna cycle the compressor by spinning the clutch plate, possibly three or four revolutions.
Remember when changing out the compressor, you must check the compressor for the correct amount of refrigerant oil that is the recommended amount from the manufacture which should be stamped on the compressor. Next we going for flushing the system in case we have a compressor that comes apart internally and contaminates the system, so we might have metal shavings. What you'd want to do with the system completely installed minus the compressor: you wanna shoot the flush fluid from one side of the compressor hose fittings using hot air to push the fluid through the complete system and coming out of the other port.
You can go ahead and start installing the new components. Put the hose manifold back on. Now we're gonna cycle the compressor approximately five or six rotations and turning the clutch plate. Install the compressor clutch wire and install the serpentine belt. When installing the new components make sure you use all new O-rings that are included in the O-ring kit provided.
Install AC Compressor System - Part 3:
Now we're replacing the O-rings here on the Ford spring lock fitting, which is very important as the refrigerant will leak past the O-rings. Use the O-rings supplied in the O-ring seal kit. Now we're ready to install the new orifice tube. All you want to do is with your refrigerant oil keep the O-rings on the orifice tube wire : this helps installation. An orifice tube is directional there'll be an arrow located on it and that is the flow of the refrigerant, in this case going down.
Now, the way you know the Ford spring lock fitting is engaged all the way: push down until you hear it click. Physically try to pull it back out if you can't, you know it's locked in place and put the safety retaining clip back on. Now we're ready to install accumulator.
When all the fittings are snug, then fasten the bolts for the mounting brackets. Next, we're gonna tighten up the hose fittings to the accumulator. Once again, make sure you use the backup wrench. Next, we're gonna install the switch on the accumulator. This switch, you don't need to use a wrench just hand tighten it. Put the electrical connector back on. Make sure you lubricate the orifice tube when installing and make sure that it's installed properly following the arrow of the direction of the refrigerant.
Now, we're gonna evacuate the system. With both of the couplers installed and both of your valves open all the way, you can hook up to your vacuum pump and turn it on. Now notice on the low side gauge, it's to dry vacuum. We're gonna leave the vacuum pump on for approximately 30 minutes to an hour. After you pull the deep vacuum on the system you're ready to recharge the system. Using a charging scale put the recommended refrigerant amount back in the vehicle.
We're going to go ahead and recharge the system. Start by turning off the vacuum pump. Now, the refrigeration scale will manage the amount of refrigerant. Never put it back in the system. This vehicle calls for two pounds and five ounces. Now the system has partial charge, now we're gonna enclose the high side on the gauge set and then start the vehicle.
Started the vehicle and ran it with the compressor off and inspected the serpentine belt to make sure that they are on the poles correctly. After all the work is completed go ahead and check your evaporator temperature by using a probe thermometer in one of the vans. Repairing job is now complete, everything is working properly and our customers is ready to go.