86 Carrera AC compressor

[janz]

Hate to beat this subject to death but. My car came with all the parts and pieces intact for AC. Here's what I've found so far. Compressor wire disconnected, system empty, front blower motor for condensor cooked. Now I have the compressor off the car and it turns fairly easy and can hear only sucking like noise so I think it may be Ok. Tried tipping it on its side in a container to see if oil comes out, so far nothing. I remember years ago doing AC work (cars) and always put new oil in at the same amount you get out, nothing came out after sitting for 1/2 hour. Should I still put in the 2 oz Bentlys says the compressor holds? Next I plan to replace the R/D with new one, shouldn't need oil there. Then replace all the easy to get to "O" rings. Then pulling a vaccumn on the system to check for leaks while waiting for my new front cond. blower assembly from our host. If all holds well I plan on using the freeze 12 and see what happens. Hoses look good (almost look new) but if I have any troubles I'll spring for the rennair complete kit, nothing worse than a black and black 911 on a 90 degree day even in New England. So any ideas as to why no oil is coming out of compressor, tried turning it to find the open valve/piston that my let the oil out but no oil, and should I just go ahead and put the 2 oz of oil in as other may be missing but I seem to remember the oil never leaves unless you remove it. I would hate to have to much oil in the system as that can be just as bad as to little. Figured I'd give it a try before springing for the $1700.+ kit.

[janz]

BTW its a nippo denso compressor.

[mthomas58]

The total oil capacity for your system is 6 oz. At a minimum to get you up and running I would do the following:

1) flush the system to get rid of all old oil and contaminants - particularly if you don't know the history of the A/C system (do not flush the expansion valve)

2) replace all o-rings (use blue nylog on all o-rings & threads)

3) replace the drier

4) pour 3 oz of the correct oil in the compressor and pour 3 oz down the low pressure suction line at the compressor.

5) vacuum, leak test and charge.

If your compressor is bone dry, oil has leaked out somewhere and you may still have a leak somewhere in the system. If your system is original, the components are past their useful life and subject to failure at any time.

While replacement kits sound expensive at first, piecemeal repairs on an old system can quickly nickel and dime you to death (ask me how I know).

[rusnak]

I have to agree with Mark. He has the right sequence too. In fact, I would do #1 a few times just to save yourself some dough.

[janz]

Well haven't known a flush job that was worth a crap. As for expense so far its only for the receiver dryer. Thats only $40 bucks so I have everything else its just a matter of give it a try. Actually found a small amout of oil coming out of the compressor finally so I know its not bone dry. The system (mine) only holds 4.8 oz of oil. I guess I'll let it drain a little longer and add the 2 oz and cross my fingers for a good vaccumn test. I do beleive the system was evacuated at some point for other work to be done and it seems to have been properly closed but just never recharged, at least thats what I'm hoping for. The freeze 12 is pretty cheap as I can get 3 total charges + for $100. so I guess I'm going to give it a try, never know I may get very lucky.

[mthomas58]

Originally Posted by janz

Well haven't known a flush job that was worth a crap. As for expense so far its only for the receiver dryer. Thats only $40 bucks so I have everything else its just a matter of give it a try. Actually found a small amout of oil coming out of the compressor finally so I know its not bone dry. The system (mine) only holds 4.8 oz of oil. I guess I'll let it drain a little longer and add the 2 oz and cross my fingers for a good vaccumn test. I do beleive the system was evacuated at some point for other work to be done and it seems to have been properly closed but just never recharged, at least thats what I'm hoping for. The freeze 12 is pretty cheap as I can get 3 total charges + for $100. so I guess I'm going to give it a try, never know I may get very lucky.

With a non-working system you've got nothing to lose by trying a low cost repair. Yea, you might get lucky. However, this forum is filled with those of us who have not been so lucky.

Keep us posted on your progress.

[janz]

OK changed the "O" rings and added 2 oz of oil to compressor. Reinstalled everything except new RD just to see. Put a quick vacuumn on system and went right down to 25-26 left it there for 5 miinutes and isolated system from pump. 15 minutes later still held steady at 25-26 so started pump up again and leaving overnight in morning will isolate again and let it sit till I come home from work 8+ hrs and see where it is then. If good (lucky) will change RD and check again and draw down for 24 hrs then maybe add the freeze 12 and then have to wait for front blower for condensor to come in delivery date July 7th the waiting will kill me if all is Ok to that point. Will keep you all updated, if gambling man figure my odds at being sucessfull at about 100 to 1. LOL

[rusnak]

might want to change shraeder valves too since they are cheap and well, it will give you something to do while you are waiting for the big brown truck.

[janz]

The ones on there look great but I do have some that came with the kit I bought for new parts. Not a bad idea. The truck is red white and blue (Fedex).

[rusnak]

which kit, the conversion kit? Did you buy it to do the conversion, or do you mean to obtain the o rings? The reason I'm asking is that you don't want to mix the diff types of oil, as I'm sure that you already know.

[janz]

The kit was just a seals kit only from pelican. Has O rings, some plastic washers, shreader valves and caps. The O rings in the kit are green will they be OK to use with R12? I think its all black for R12 and green will work with both R12 and 134 ?

[janz]

Ok here it is. My freeze 12 came in and wanting to try everything out before my front blower assembly for front condesor comes in next week I took an old 12 V fan and hooked it up to blow down on the front condensor, putting my hand under the car I could feel plenty of air moving through the condensor so I figured this would work OK at least for the big test. Had nice vacuumn on over night and then isolated in moring before going to work, came from work after 8+ hrs and vacuumn was still perfect so I guess it was time to add the freeze 12. First can went in almost completely using the no running suck it in the high side using the vacuumn in the system. Closed hi side and opened lo side and Started up and set to 2,000 rpm and started adding rest of first can and second can. Had thermometer in drivers side AC vent and it started getting cold. Almost got the complete second can in (figured it needed 3 cans total) and something started to go wrong. I opened the engine lid only to see oil and refrig spraying from compressor pully. Crap I thought the seal on the compressor was bad. Nope when I closed the engine lid first time it pushed the low side guage hose right against the pulley and burnt a hole right through it. I quickly disconnected the low hose from the compressor valve and everything stopped spraying. Now I'm wondering if I sucked in any air or can I just continue with another hose. Well I decided to add another 1 1/2 cans of freeze 12 and had a press of 260 hi and 20 low so I stopped there and checked my thermometer. 40 degrees holding solid from the vent. Cleaned everything up and buttoned it up and took it for a ride. Very nice having AC and it stayed between 40 and 45 degrees the whole time, city and highway. Do you think I may have sucked in bad air when the hose ruptured? Should I leave well enough alone? I am considering to having it evacuated and start over from scratch when my real front blower comes in but leave it for now. Any thoughts on this as I would rather have the correct volume of refrg than go by the guages. I still have enough freeze 12 for 2 + complete fillings of the system. Did I mention how nice it is to have AC in the middle of the day, now I don't have to wait till the sun gets low or goes down to enjoy going for a drive. BTW the hi side was 150 and the low was around 35 when the hose blew. The system is smooth and you can't even tell when it kicks on except for the cold air coming from the vents and doesn't seem to drag the engine down at all or loose power at all nor does it get any hotter than normal.

[rusnak]

After driving for a longer distance, say 10 miles, check your vent temps again to see how cold is your ultimate cold. I think you'd want it to be in the low to mid 30s, that way your AC can also dehumidify the cabin air.

[janz]

38 - 39 degrees is the coldest it got, I'm happy with that, in fact very happy with that as I had to turn the fan down because it was getting like a walk in cooler in the cab. The cab itself is very tight so it doesn't take much to get it cold inside. As long as I'm not sweating in there I'm very happy. Still looking for thoughts on should I redo it because of the hose problem during charge.

[rnln]

38-39 degree at the vent? What was the outside temp at the time?
My experience, it kick in smooth too, can't even notice, but when I accelerate on hwy, I can tell that it is much slower.

[GH85Carrera]

I can't see how air could be sucked in when refrigerant was under pressure and blowing out. As long as there was pressure on the system air should not go in.

[janz]

That was my thought also that there was no way to have air sucked in when it was blowing out. Then thinking about it the low side is marked as suction and the high side is marked discharge so i guess i'm Ok. Ambient temp was 85 degrees when i had 40 degrees at vent.

[rnln]

Great. I got similar. On 80+ day, I got as low as 43 degree. On 90+ day, I got 48 or 49 degree. The thing is it takes a long time to get there. Not sure how long it'll keep it that way.
Thank to Rusnak, jFairman and others.

[janz]

You asked for an update on my results. System is working. Yesterday was 97 and today was 94 out there with high humidity. Temp at vent was 51-56 degrees. Not bad for an old system that was dry for who knows how long. Cab is pretty tight so I think this helps a lot. Kept me cool enough for comfort. Condensation was plentiful coming out of bottom of car. So far I guess I got lucky, now its just a matter of how long it will last. For the $80. I spent on it so far I am pleased with the results. Guess you never know till you try. The freeze 12 worked pretty good for a cheap replacement of R12 without oil change or flushing or taking apart all the components or changing expensive parts. New receiver dryer, new "O" rings all around and a good vacuumn overnight and 36 oz of freeze 12 did the trick so far.

[rnln]

Similar to what I got. Yeah, same question, how long it'll last. Mine did not last that long, but still hope it last this time.
Good luck.