Blown AC Compressor Seal - What's my Play?
04-18-2015, 05:48 PM
#1
Three Wheelin'
Thread Starter
Blown AC Compressor Seal - What's my Play?
As per my timing belt thread the car hasn't been driven much for the last several months. Took it out last night for an hour or so with AC on. Found a significant puddle of lightweight oil under the front passenger side of the engine this morning, traced it upwards to the front of the compressor which is very wet including the felt wick which is absolutely soaked. Assuming this means the seal has given up so now I need a strategy for fixing it since I'm even more clueless about AC operation than I am about other repairs.
The system is front AC only, is still running R12 and holding a charge well for now. I purchased a rebuilt compressor and drier a few years back when I thought the compressor bearing was going (turned out one of the pivot bolts had become very loose causing the rattle we mistook for bearing noise.) What should my plan of attack be?
I assume step one is to take it to a shop have the R12 captured.
After that I'm unsure - should I have them flush at this time and then replace the compressor and get hoses rebuilt myself and do the o-rings, then take it back for evacuation and recharge with R134? Have an AC shop do the whole thing? If I just have a shop do it is there anything 928 specific I need to make sure they deal with? Any recommendations in the South Bay for a competent shop?
Obviously am cognizant of costs for the job, but I definitely only want to get in there once so please provide any advice you might have for me.
The system is front AC only, is still running R12 and holding a charge well for now. I purchased a rebuilt compressor and drier a few years back when I thought the compressor bearing was going (turned out one of the pivot bolts had become very loose causing the rattle we mistook for bearing noise.) What should my plan of attack be?
I assume step one is to take it to a shop have the R12 captured.
After that I'm unsure - should I have them flush at this time and then replace the compressor and get hoses rebuilt myself and do the o-rings, then take it back for evacuation and recharge with R134? Have an AC shop do the whole thing? If I just have a shop do it is there anything 928 specific I need to make sure they deal with? Any recommendations in the South Bay for a competent shop?
Obviously am cognizant of costs for the job, but I definitely only want to get in there once so please provide any advice you might have for me.
Last edited by zekgb; 04-18-2015 at 06:05 PM.
04-18-2015, 06:08 PM
#2
Rennlist Member
Kevin,
The responsible thing is have the gas sequestered [over here they just blow it in the direction of a Greenpeace ship]. A good auto a/c shop should be able to remove the compressor for you with minimal extra effort effort when they do this- not sure how it attaches on your model year but on my S4 motor it was not too difficult to get out of the cradle- just a little fiddly/cramped when working on your back.
Has the a/c cooling packed up yet? If a seal has gone the gas lasts no time. I had a problem with my a/c compressor but it was a slow leak from the body gasket joints. I did not trust my local auto a/c chappie to physically work on the car so I had the main agents deal with the gas and removing the compressor and then I took the compressor unit to the a/c shop. They stripped the compressor apart, cleaned up the internals, fitted a new swish plate, new body gaskets and a new seal. While they were at it I had them fit a new solenoid clutch as well [quite cheap over here]. The shop also made new barrier hoses for me. Reluctantly I had to run with R134 as I was told there was no more R12 in town-period. To be fair it seems to work reasonably well on all but the very hottest days- however once the needle hits the 44C mark it does not like pootling around in traffic. Surprises me that you chaps over the pond can still get R12 if you try hard enough.
Regards
Fred
The responsible thing is have the gas sequestered [over here they just blow it in the direction of a Greenpeace ship]. A good auto a/c shop should be able to remove the compressor for you with minimal extra effort effort when they do this- not sure how it attaches on your model year but on my S4 motor it was not too difficult to get out of the cradle- just a little fiddly/cramped when working on your back.
Has the a/c cooling packed up yet? If a seal has gone the gas lasts no time. I had a problem with my a/c compressor but it was a slow leak from the body gasket joints. I did not trust my local auto a/c chappie to physically work on the car so I had the main agents deal with the gas and removing the compressor and then I took the compressor unit to the a/c shop. They stripped the compressor apart, cleaned up the internals, fitted a new swish plate, new body gaskets and a new seal. While they were at it I had them fit a new solenoid clutch as well [quite cheap over here]. The shop also made new barrier hoses for me. Reluctantly I had to run with R134 as I was told there was no more R12 in town-period. To be fair it seems to work reasonably well on all but the very hottest days- however once the needle hits the 44C mark it does not like pootling around in traffic. Surprises me that you chaps over the pond can still get R12 if you try hard enough.
Regards
Fred
04-18-2015, 07:41 PM
#3
Three Wheelin'
Thread Starter
Upon further review, although the compressor seal is in fact leaking and will need to be replaced the actual puddle source seems to be either the timing belt tensioner or the crank seal. The oil doesn't seem thick enough to be coming from the engine, but that area is clearly where the large leak is originating. Won't know for sure until I get back in there, here comes teardown number three. Yay me!
04-19-2015, 06:47 AM
#4
Nordschleife Master
Then I discovered that those cans of "compressed air" for blowing your computer clean are commonly r134a (aka HFC-134a aka Tetrafluoroethane).
http://en.wikipedia.org/wiki/Gas_duster
04-19-2015, 10:55 AM
#5
If the system has refrigerant in it, have it removed.
Take off the compressor. If it is a stock Nippondenso model, disassemble it and inspect the piston rings, cylinder bores, wobble plate and section of the shaft where the seal contacts. If all looks good, order a compressor seal kit, all system o-rings, ester oil and a drier. You can handle the R&R of the hardware. If you are experienced in evacuation, charge and testing you can handle that if you have the equipment or can borrow it. Otherwise job that out.
If you find 'debris' or sludge in the compressor oil you will need to liquid flush the lines, evaporator and condenser. 3 cans of Interdynamics Professional-Grade Aerosol Power Clean and Flush (17 oz.), pn CA-1, available in most brick and motor autoparts stores or online. You can't flush a drier, compressor or the TEV.
Inspect the 2 hoses attached to the compressor for signs of cracks or oil seepage, replace if shot.
928 AC
Take off the compressor. If it is a stock Nippondenso model, disassemble it and inspect the piston rings, cylinder bores, wobble plate and section of the shaft where the seal contacts. If all looks good, order a compressor seal kit, all system o-rings, ester oil and a drier. You can handle the R&R of the hardware. If you are experienced in evacuation, charge and testing you can handle that if you have the equipment or can borrow it. Otherwise job that out.
If you find 'debris' or sludge in the compressor oil you will need to liquid flush the lines, evaporator and condenser. 3 cans of Interdynamics Professional-Grade Aerosol Power Clean and Flush (17 oz.), pn CA-1, available in most brick and motor autoparts stores or online. You can't flush a drier, compressor or the TEV.
Inspect the 2 hoses attached to the compressor for signs of cracks or oil seepage, replace if shot.
928 AC