CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Compressor Failure

Two weeks ago, I had a/c repairs done which involved the replacement of the a/c field coil unit and a condenser fan motor. Yesterday, the compressor seized up. Could the repair, if done incorrectly, have caused the part failure?

Sure - Maybe they evacuated the system but just added coolant, forgetting to add lubricant.
Are you sure your compressor is indeed seized? There’s usually a nut on the spindle that you can turn with a wrench. Can you turn it manually?

Lubricant is on the invoice. It is locked up clockwise. It is free counterclockwise. The proprietor told me that because it can be turned counterclockwise, the system does not have to be flushed. By the way, the facility is top-rated by Washington Consumer Checkbook for doing the job correctly the first time, and for price. However, I practiced consumer law for 20 years, and remain suspicious.

So they really just replaced some electrical parts to the AC, it didn’t need any thing else?
Didn’t recharge, add refrigerant?
Not sure what makes a compressor lock up if they didn’t do anything else.

Right now your AC clutch engages properly but your belt slips like crazy, I take it?
The way I understand it is that some compressors give more resistance one way than the other. That could be normal. FWIW, my tacoma and subie ACs turn both ways pretty easily.
If they indeed added lubricant, they must have opened the system. Maybe it was charged improperly or moisture or air got in. The way I understand it, you could get a condition called hydrostatic lock that totally hoses the system up. With air/moisture in the system, some chemical reaction between it and the refrigerant that does a job on seals and the pump.
Note that I’m an not an AC expert by anyone’s stretch of the imagination, but just replaced my Tacoma’s condenser and dryer a couple of days ago: did a lot of reading on the subject to make sure I did it correctly, got the manifold tool, evacuation pump, a couple of cans of R134 and went to town.

Maybe someone else here has seen more AC battles than you and I and can lend some insight.

Off the top of my head I don’t see a field coil and condenser fan replacement contributing to a failed compressor.

However, there are a lot of unknowns about this repair and symptoms leading up to the repair that leave the possibility open that a mistake during the process could have caused the problem.
I’m not wild about the comment regarding the counterclockwise/doesn’t need to be flushed scenario.

A failed condenser fan motor can create problems for the compressor and it could be that the compressor was damaged goods from the get-go because of that.

It requires special removal and installation tools to change the field coil on the compressor. If they didn’t use these tools, and instead pried the old coil off and then and then pounded the new one on, that will definately damage the compressor.

Tester

I meant if they pried the clutch plate off and then pounded the clutch plate on.

Tester

I agree with Tester but made the assumption, right or wrong, that the shop did not use a large screwdriver (or several of them) to remove the clutch and a BFH to install it. :slight_smile: