Bricklin AC Repair
By Scott Isensee
†††††††††††††† On a recent drive in my 1975 Bricklin, it started making an awful noise under the hood and the AC wasnít blowing as cold as usual. Lifting the hood, I could tell the noise was coming from the AC compressor.
My first step in troubleshooting was to check for leaks and top off the Freon. A low Freon level will sometimes cause a compressor to make noise. There were no leaks and the Freon level was good.
I put a stethoscope on the compressor and could tell the noise was coming from at or near it, but I couldnít tell for sure whether it was coming from the compressor or the AC clutch. I took off the AC belt and the clutch spun freely. It didnít seem to have bad bearings, but, since a clutch is far easier to change than a compressor, my next step was to remove the clutch and check it out carefully. I bought a spanner wrench to hold the clutch in place while taking the bolt out.†† A spanner wrench has three tabs that fit into indentations in the clutch face to hold it still. You canít use the AC belt to hold the clutch in place because the outer ring of the clutch spins independently from the center section.† Many auto parts store loan out tools like spanner wrenches, if you donít want to buy one. Alternatively, you may be able to energize the magnetic hub to hold the clutch in place rather than using a spanner wrench.
With the spanner wrench holding the clutch face still, I used a socket wrench to remove the single bolt in the center of the clutch. The clutch is press fit onto a shaft so the next step was to pull it off. Unlike most compressors, the AC compressor on the Bricklin doesnít require a special puller to remove the clutch.† You just put a large bolt into the center of the clutch to slowly back it off the shaft. Use the spanner wrench again to keep the clutch from turning. After removing the clutch, I inspected and all looked good. The most typical point of failure on a clutch is the bearings. If it spins smoothly and there is no noise, the bearings are good.
Now, as I suspected all along, it was clear the compressor was the problem. The York compressor used on the Bricklin is very common. It was used on many makes and models of cars for many years. It was especially common on Fords. I have had bad luck in the past with rebuilt compressors. They often leak at the main seal. Since brand new compressors are readily available and fairly inexpensive, I looked for a new one. The AC compressor on the 1975 Bricklin is a York T210L. After a little research, I found that a Four Seasons 58064 is a new, direct replacement for the York compressor. It looks identical to the original compressor other than the fact it is bare aluminum rather than painted black. I found one for $158 on Ebay. A seal is required on each of the output ports of the compressor. This is an o-ring made out of a material appropriate for use with Freon.† The part number is Four Seasons 24610. The Bricklin service manual refers to these o-rings as service valve gaskets.
I decided to replace the clutch as well. Even though the old one was still good, I didnít want to take any chances on having it fail at a later date. The clutch is Four Seasons 48812. I was unable to find a new one anywhere so bought a rebuilt. There are several styles of clutches for the York compressor and only this one fits the Bricklin so make sure you get the right one. Many cars use a two pulley clutch, but neither of those pulleys lines up with the belt on a Bricklin. The Bricklin AC clutch has a single pulley with a balancing weight behind it.
The AC system needs to have oil mixed in with the Freon to lubricate the compressor. The Bricklin AC system should have 7 ounces of oil. Most new and rebuilt compressors come with oil in them, but not all do, so you need to check by opening the access plug on the side of the compressor and fashioning a dipstick to measure the oil level.
I bled the Freon from the system. Once the system was empty, I removed the hoses from the compressor. Unlike many cars, the Bricklin engine has the AC compressor right up on top where it is relatively easy to get at. Despite that location, some of the bolts were in tight spots and take some work to remove. After some skinned knuckles and use of language intended to intimidate ornery bolts, I got it free.
It is best to minimize the amount of time you keep the system open to the air since moisture may gather in it and moisture is very bad for AC systems.† There is a receiver/drier in the system that many people recommend replacing when you open the system up.
Since the receiver/drier isnít readily available for the Bricklin and since I was going to button the system back up quickly, I left my old one in.
I placed the new compressor in and tightened down the mounting bolts. Next I bolted the new clutch onto the compressor. Note that I waited to mount the clutch until the compressor was bolted in. Thatís because you have better access to the compressor mounting bolts without the clutch in the way. Use that spanner wrench again to hold the clutch from moving while tightening the center bolt. You wonít want the bolt too loose or too tight so it is best to use a torque wrench. It should be torqued to 20-30 foot- pounds.
Now I put in the o-rings and tightened the hose fittings down on the compressor.† The two hoses must go to the same connections they were on originally.
I placed the belt on the clutch and adjusted it for the appropriate amount of tension.
Next the system needed to be evacuated. This draws most of the air out so that the system can be filled with Freon rather than air. This also serves the purpose of drawing out any moisture that may have accumulated in the system. I borrowed a vacuum pump from a local auto parts store.† The pump needs to be run for at least 45 minutes. It attaches to the suction (top) fitting on the compressor. I connected the pump through my AC gauge to the compressor. My gauge shows vacuum as well as pressure so I was able to verify that the max vacuum level had been reached and maintained.
After the system had been evacuated, I turned off the pump and closed the valve on my gauge. The gauge continued to read the vacuum level. I wrote down the reading and left everything to sit for the night. In the morning, I verified that the gauge still read the same vacuum level. This indicated there were no leaks in the system.† If there had been a leak, it would need to be fixed before Freon should be added. I then ran the compressor for another 45 minutes just for good measure.
Now, it was time to add Freon. I kept my system running R12 as it was originally designed for. Many folks are converting to R134 these days since that is cheaper and more environmentally friendly. If you decide to convert to R134, you need to flush out your AC system, put in a different type of oil and make sure seals are of the appropriate material for R134. It is slightly less efficient so your AC system wonít run quite as cool and it leaks a little faster because it has smaller molecule size and the hoses in our Bricklins were not designed for it. If you donít have your own supply of Freon (either R12 or R134) you may need to go to an AC shop to have it added.
The Bricklin AC system requires 2 pounds of R12. I connected my Freon tank to the suction side of the compressor and let it fill until the pressure stopped changing on my gauge. Then I started the engine and ran the AC on full letting it continue to suck in Freon until it had 2 pounds. One way to measure this is to weigh your Freon tank. A second is to watch the sight glass. When the bubbles stop and the liquid Freon is running clear, it is full. A third technique is to measure the high and low side pressure with gauges. The recommended pressures vary with temperature and humidity and are typically provided in a table in the repair manual.
I took it for a test drive and luxuriated in cool AC and the satisfaction of a job well done.