Automotive Air Conditioning Information Forum (Archives)

Provided by

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

How to verify if a compressor is blown

geezee on Mon July 21, 2008 10:18 AM User is offline

Year: 1992_96
Make: Honda
Model: Civic
Engine Size: 1.6l
Refrigerant Type: 134
Ambient Temp: n/a
Pressure Low: n/a
Pressure High: n/a
Country of Origin: United States

Hello all,
my first post here, have gotten some great info here already.

Here is the deal,
subject car is a 1992 Civic DX (1.5L) chassis with a 1996 Civic EX engine (1.6L) swap, which my son and I performed 3 years ago.
So the evaporator and expansion valve, accumulator, and some AC plumbing is 1992 Civic vintage, which was R12.
The Compressor, condenser (I think the condenser, hard to recall!), etc are from the 1996 Civic donor car which would have been R134.
The AC has been non-op for about 2 years.
We got the engine swap all together pretty well and the car has operated just fine mechanically for the duration, excluding AC. I was a complete AC system noob (and am only marginally better now!) and this is what I did. Basically everything in the book, WRONG. We reconected the system, using all the existing stuff, including the old accumulator (I know, I know) and charged it with refrigerant, filled with oil. Didn't flush it, didn't evacuate/dry it, nothing. It actually blew some cold air for a while, incredibly enough. It also seemed to put an excessive load on the engine when the compressor clutch engaged, like perhaps it was overfilled w/oil (which it probably was), or maybe the expansion valve puked out, or there were excessive pressure(s) someplace, etc.... So, knowing 'this is not right' we simply abandoned using the AC in the car. Took it into a shop one time and all I recall is thier saying "you need an expansion valve, at least".

Over time the refrigerant has leaked off. The system had no pressure in it this past weekend when I decided its TOO HOT in FL to not have AC in that car (its now my daughter's)- so I tore into the system.

I removed the PS pump and reservoir to get at the compressor.
Removed Compressor.
Removed Accumulator
Removed Condenser and fan assy
Removed Evaporator/expansion valve assy (what a PAIN) - the evaporator was a crudded up mess, on the outside at least.
Removed blower assy (to get the Evap. out, and to clean it also)

First off I wonder is there ANY way to verify if I have blown this poor, abused compressor up ? That is, short of reassembling the entire system, replacing the (other) recommended stuff, evacuating, charging, and 'seeing if it works' ? Its a Sanden, tho I am unsure what model (remember, its off the 1996 Civic EX engine).

I did not measure how much oil came out of the compressor (since I plan to refill per spec) , what (oil) that did drain out was an amber color. There was no evidence of aluminum or other contaminant in the oil which came out of it. It was probably 3 ozs of oil.

I also see its NOT recommended to flush a compressor in any way. I plan to just cycle some new oil thru it, discard, repeat a few times (manually) unless somebody else has some clever ideas.

After trying to clean my evaporator I decided its just too screwed up to salvage.
I did notice when I flushed the evaporator (prior to deciding to scrap it) that some COMPRESSOR OIL came out of it. Is that normal ? Probably 1-2 ozs, hard to tell quantity tho as it was blasting out at about 80psi, along with the flush solution.....

I ordered a new evaporator, expansion valve, Orings, and accumulator from ackits.

I flushed the condensor and no debris came out of it, just flush solution, and it was pretty free flowing. I'm presuming its 'okay' to reuse and will flush it a couple more times, both directions (as I hear they can be real crud traps in the system). I will flush all the other AC lines also, prior to reinstall.

I'll swap out all the orings at reassembly. Those Orings I've seen on the hoses thus far are black rubber, not green. No idea if this is legacy R12 system orings, or thats what the OEM used, black, or what....

NOt knowing if I've destroyed this compressor, my plan is to continue flushing the components I'm reusing, reconnect them w/the new stuff (when it arrives), reinstall the old compressor with appropriate oil fill, pull a minimal vacuum on the system just to get SOME of the humid FL air out of it (I have a rinky-dink little venturi type vacuum) - then take it in to be professionally evacuated/charged/leak checked and see what happens..... Maybe rent a real vacuum pump and do the charge myself, don't know yet.

So anyway any other advice and guidance in reviving an unused AC system is greatly appreciated


mk378 on Mon July 21, 2008 11:31 AM User is offline

That should be a TRS-090 compressor. They often let you know when they're blown out because a big hole will form in the side and several pieces get left behind on the road.

If you don't see metal flakes in the oil, the compressor turns freely, and it will compress air when you hold your finger over the outlet while turning it by hand, it is probably worth trying it on the car. Note that it is of a scroll design so you get one pulse of pressure per rotation instead of several like a multi-cylinder piston compressor does. This will also normally cause the high side gauge needle to fluctuate at idle, leading some techs who don't know about a scroll compressor to conclude that it has a "bad cylinder."

Flush compressors with oil only. Since PAG oil deteriorates when exposed to moisture in the air, do this just before installing the compressor and closing up the system. It may be easier to work on the compressor from underneath, after taking the left wheel and the plastic splash guards off. Flushing a parallel flow condenser can be a problem getting all the flush solvent out.

I think all the 1992 major parts are the same design as the ones used from 94-95 with R-134a, so should be no problem using 134a in that car.

The evaporator box is designed to be removed without taking the blower out. Pull it straight out thru the glove box opening after removing the bolts and clamps and disconnecting the refrigerant lines under the hood.

geezee on Mon July 21, 2008 1:16 PM User is offline

Thanks !
Ya in doing some basic flushing with some compressor oil, after having drained the old stuff out, then spinning it by hand. I didn't plug the orifices but it did indeed make some sputtering noises and spewed a few oil droplets as the innards moved about.... I noted the direction of rotation indicator and went that way only. I'll try plugging and see if it blows back. That'd be great if the compressor is salvagable, especially after what I put it through...! Thanks for the advice on the oil/moisture, I'll crack open a brand new can of oil, flush, drain, and re-fill immediately before closing the system up.

My manual on the car indicated the Evaporator could be dropped out w/o fan removal, also, but I couldn't get it free. And the fan had crap in it like the evaporator housing did also, leaves, crud, old rubber gasket material (breaking down) etc etc -so I wasn't too bad with dropping it, too , for cleaning if nothing else.... Either way that thing really sucks to work on in my opinion ! I hope it goes back in reasonably easy.

I'll remember the compressor can be accessed from underneath. If it doesn't come back to life when I'm done here I'll be able to pull it (only) from the bottom for replacement.... This time I needed to get my PS pump and condenser and accumulator out for work anyway so the 'top access method' worked this time pretty well.
Thanks again,

wasp on Mon July 21, 2008 2:23 PM User is offline

compared to a lot of other cars i've worked with, the evaporator/blower both come out far easier. you only need to take out the glove box, no dash removal required!
the evaporator comes out first, then the blower. the battery comes out to get to the evap lines, then on the inside there's two screws for the recirc door servo and 4-6 screws/nuts/bolts that hold the evap in (12mm hex head). the blower is 4-5 fasteners as well. when disassembling the evaporator housing there are some spring-like fasteners and TWO screws (don't forget these!).

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.