A/C Fix You May NOt Need A New Compressor

KrashDH said:

You should be fine with the old bolts and 1 new one, but if you want the peace of mind replace them if you want. The reason I say this as the OEM bolts are hardened. They have a high tensile strength but VERY little elongation before failure. Ie they will just snap and not neck down/yield before failure. I inspected all my old ones and there is no noticeable elongation or yield. I actually re-used 1 of my old ones because I bought 6 instead of the 7 needed.

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I think I will have to take the head back off to get the broken one out, as it looks like it snapped at the compressor body. At that point I may as well go with all new.

I went ahead and charged it so I could tell if the RCV fixed my problem. It is cooling fine and not leaking, but I think the head could eventually warp with a missing bolt.

Incidentally, changing the dryer was a PITA and I was bleeding from both hands. The Steve Martin short story Cruel Shoes popped into my head. https://www.youtube.com/watch?v=feTrJSWnqdk

3turboz said:

Incidentally, changing the dryer was a PITA and I was bleeding from both hands.

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This was the hardest part of my experience as well. There is not much room in there for normal hands. When you can finally get a tool on that 4mm clamp SHCS, it's one or 2 clicks at a time to loosen it. Getting it out is a whole 'nother game. For me it went in easier than it came out.

I also replaced my stock AL oilpan with the hybrid Al/steel pan at the same time the compressor was out. That was another fun one with those two bolts against the transmission. I "pre modified" the pan on the bench for the steel flanges I knew would get in the way, and then modified the interfering location on the compressor with it on the car and the upper compressor mounting bolt in so I could swing it down and touch it up. WOrked out really well. Buut, now it's September. Well almost October, and A.C won't be needed much round here

3turboz said:

I have read this entire thread today as well as others.

AC has been getting warmer for a few days and pressures are a bit wonky, but not near equal. Low side is a too high (50) and high side was 200. Both fans working fine.

So I am thinking either the clutch is slipping, the RCV is bad, or the expansion valve is stuck wide open.

My real question is whether it is worth trying the RCV on a 230,000 mile compressor or if it is best to spend a couple hundred more on a new compressor. How long can one last?

I am thinking it might be like when I put a regulator and brushes in my Alternator and got another year out of it, but then the bearings went out.

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And after 11 months the RCV looks to be stuck again. Time for a compressor this time I think.

You probably had some gunk in the unit (from overheating) that got loose after you replaced the valve. You weren't circulating much refrigerant, then you are, and..... oops.

Get a TXV (and of course a dryer) while you're at it, and replace all three -- plus flushing out the lines. The black gunk that is likely in there is carbon from the oil overheating (which caused the original failure) and it will plug up the new unit if you don't get it out of there. If you pull the TXV and see what looks like carbon on the high pressure orifice inlet side then the entire system is contaminated and you need to get it out of there.

While you're doing it replace all the O-rings -- they're cheap and you'll be quite annoyed if you do all that work and wind up with a leak. Also consider buying replacement service ports (they're easily replaced) as they're also inexpensive and, same deal -- if you have one leak when you disconnect after recharging... you'll be swearing.

AC in my car had worked the last I'd used it (sometime last year?). Went to use it when on a recent road trip and NADA. 202k miles and no known work on the AC: I got the car with 113k miles and I've never done anything to it.



Both fans work. Clutch is engaging.


Static pressure: L:50 H:48
Running pressure: L:28 H25


From what I've read this sounds like it's an issue with the RCV. Is this a failed RCV or could it be a stuck one (and I might be able to smack it back to life)?


IF I'm looking at needing to replace the RCV how much work is it to remove the compressor vs doing this in-car? My car came to me from Minnesota, without a splash shield, in which case there's an extra risk of having stuff not want to cooperate.


Not sure if my hands have recovered from doing AC work on the wife's car a good three years ago; the drier was a bear (things didn't line up real well and I had to use a dremel to alter part of the radiator, plastic piece, in order to get one of the lines to connect up).

Are you sure your not just low on Freon?
Static pressures just seem a little too low.

No idea. I thought that I'd read that really low levels can keep the clutch from operating? (and high pressures can do something similar)


I'd love for it to be something this simple. I suppose I'm going to have to at least shell out for a recharge.

On my cars I’ve seen static pressure on both gauges just over 100 psi.....

No doubt that my pressures aren't good.


Do folks know of a way to evacuate a system? Can I put the "genie" back in the bottle (I've got an empty can- leftover from AC work on the wife's car and I know there was some in there when I put it on the shelf but now it seems empty)? I've got PAG oil and a vacuum pump (along with my gauges). Perhaps still best to just go to a shop (cost vs headache)?

I know it’s frowned upon here...... but for $hits and gigles you can get a can from the auto parts store and try it....you’d only be out a few bucks.
If it works then you know you have a slow leak....if it doesn’t then try a shop.....

Yeah, I don't think there's a threat of creating excessive pressure if only putting in a small amount.


Is it standard practice for shops to check for leaks (after charging)?

I think you have to ask for it......they put a dye in and run the system then look with a black light.
You can buy a similar set from the auto parts store and do it your self.
You should be able to put a can in.
Again others will chime in naysaying, not to do this but for a couple of bucks at least you’ll know what you have , then you can go from there.

According to information here I'm slightly low on the low side and very low on the high side. They state to add refrigerant. So, I suppose why not!

Give it a shot.

No real affect after adding a can: high pressure doesn't come up. Looks like it's a candidate for an RCV?

Yeah, or the compressor isn't compressing for other reasons (e.g. valve plate is trashed, etc)

UhOh said:

No real affect after adding a can: high pressure doesn't come up. Looks like it's a candidate for an RCV?

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Could be....it could also be as stated above the compressor.
You can gamble and try the RCV.....or find a good used compressor from someone parting a car out , put a new RCV in it and slap that puppy in there.....as long as you don’t have evidence of Black Death going on in there......otherwise it’s a different ball game.....

Sharing my experience opening the AC Compressor

Those considering replacement of the RCV, here are some pics of what to expect.
In this case, I was removing the RCV and replacing it with a bolt and nut. The modification allowed the Compressor to function as the old style in my Vanagon (with ALH engine). This is not what you should do (just sharing my experience and purpose.)

In the pic below, you can see the bolt in place of the RCV

Below, the RCV there in the center of pic.






For what it is worth, I reused the old gaskets without any issues at all... no leaks.
I pressure washed the AC Compressor before removing it. Then, I blocked off the port holes as soon as I removed the hoses. Once on the bench, I cleaned it again before opening........... keep it clean! And, my little garage is air conditioned which reduces high humidity exposure!

I think I'll have the system evacuated and then check to see if it's gunked up or not. If good then I may just buy a new compressor. Don't want to make repairs only to then have something go wrong: my luck would be that I'd get is all back together and then the clutch would take a dump, or the coils, or... and costs for evac and such can start to add up if doing multiple times. I could look to buy the parts to repair this one and have it on-hand for a spare (or hold off doing the repair until I need it).

Yeah if you see any of that nasty black stuff in there, just forget it, get a compressor, a dryer and TXV, flush the evaporator and condenser plus the hoses, purge it REAL GOOD (either scuba air or nitrogen; NOT shop air as it's full of the wrong sort of oil!) and then put it back together and pull a good, hard, long vacuum on it.

The new compressor will come with a new charge of oil in it, so if you flush everything then you're good. If not and there's any hint of black stuff in there you're begging to blow up the new one, but if you insist, do the calcs on the amount of oil presumed in the other components and remove that from the new compressor before you put it in.

Oh, and change all the O-rings. They're cheap but they're also a viton compound; you CANNOT use ordinary rubber or EDPM as both will disintegrate with refrigerant contact, so you have to get refrigerant-specific ones. I'd also change both service valves; they too are cheap ($5 or so for both) and the little ball loves to disintegrate over time. You will swear MUCH if you charge the system and then lose the charge you just put in when you go to disconnect and the service port doesn't seal, plus need ANOTHER dryer since you almost-certainly won't have one of those service ports laying around and thus the system will be open.

Would an AC shop be able to flush such that I only need to swap out the compressor (and dryer [and seals etc])? I'll need to have a shop evacuate the freon anyway. I'd hope that they would be able to note if the system was gunked up: always a gamble whether a given shop can be trusted; if I make it clear that I'm going to do any work/repairs then perhaps they'd be less likely to be shifty.



Also, where's the best place to get a new compressor?