A/c "problem" Volvo 780 cummins Isx

Once while I was at Volvo I talked to a guy that was there basically for the same reason. The dealer he went to at first didn't have the compressor in stock so he went and got one from another dealer and had it installed if I remember right at the TA. But with the new one it was something different about the hook up and it burnt the new one up so now he was at the dealer getting another new one put on and because he had it installed not at a volvo dealer they wouldn't warranty it so he was trying to get the TA to pay for it. Dont know if he ever did. The way he was explaining it to me that Volvo uses a couple different compressor or the went to a different type and there is something different about the hook up. Never messed with one so dont know what he was talking about

 

I agree on taking it to a professional. I don't know how the dryer/receiver is replaced without contamination. I don't know how to insure the oil charge is right except to do it right the first time because the compressor has the correct oil charge. Now the oil can be lost during refrigerant recovery or left in the system and lost during flushing.

Absolutely do not flush with soap and water, that is contamination and you will have to replace everything before it ever works again. With all due respect you are in over your head and it will already cost you more to get it fixed because you have been working on it. If you keep going, it will keep costing more.

As a trained technician I can work on anything, even if I have never seen it before, but still have little success with vehicle air conditioning. I think it is because I have never changed the dryer/accumulator but I'm not sure. If the system has been open, it needs to be replaced. I wouldn't think of installing a compressor or condenser on a residential unit without a high-side dryer, so that is probably the key. With these the limited time it is open during installation doesn't limit it's ability to collect moisture and contaminants.

I told you how to flush it but you have to read between the lines. As a licensed technician I cannot suggest something illegal. If you put anything in it besides refrigerant or an expensive solvent, made especially for flushing your specific system, you will ruin it. In addition if you get caught venting the refrigerant in the system to work on it, the fine is astronomical.

While the old method of shutting off the vacuum pump and waiting to see if it will hold a vacuum is good, it is not as good as a micron gauge.

The only way to get a proper charge is to weight it in with a scale that weights in ounces or charge using the proper method. The method would be superheat or subcooling depending on the specifications for this unit. I don't know which is correct without the specs. You would need training to be able to charge using either method.

In addition you would need thermometer equipment that can be attached to the proper locations and read multiple temperatures. Sure you can get lucky and throw in some juice and make one work, but that's what it was, luck. The reason that A/C work is so expensive is because of the skills and tools needed to do a proper job.

 

Thanks Redforeman. I thought I just had personal problems with my success rate

One summer after getting into HVAC. I had people wanting me to fix their car A/C's. I decided I could make some extra money. Of course you know now none of them wanted to spend any money.

After working on about 6 and fixing 2, I was in the hole on the refrigerant and got out while I was behind.

 

Yep it wasn't you. About the only thing you can piecemeal with any success on an a/c repair is a leaky hose/o-ring or electrical issue, provided the compressor doesn't die from low refrigerant or oil.

I've had many where you pull the coupler over the orifice tube and the black crud of compressor guts is packed in hard as a rock, and have to dig it out with a pick just to get pliers on the orifice tube tip. You can then go right to the inlet side of the condenser and pull the high side line off (compressor output at the other end) and guaranteed see more crap inside the hose and condenser. IMO there's no effing way you're going to flush that stuff out really well with anything.

The last few years I was doing that for a living, cars coming in with dead compressors automatically got quoted all high side parts to the orfice tube plus a dryer. We'd flush the low side just to make sure the oil quantity was right on the recharge. 100% success and zero comebacks. If the customer tried to nickel and dime it, we'd send them off to precision tune or someone who would deal with the comebacks. The used car dealers we serviced were the worst about doing that, and then expect all the comebacks and reclaim/recharges to be free.

 

You can't just spray freon through the lines and let the freon vent to the atmosphere, that is totally illegal. There are environmentally safe a/c flushing fluids available. We just take everything apart, fill the lines or components with the fluid and then blow them out clean filtered shop air.

 

youve got one of two options here. replace one part at a time and hope you fix it but have problems with it all summer, no money and a truck full of stress orrrrrrrr you can just get it fixed right the first time and not have to worry about it. To fix it right you have to tear the a/c system apart, throw the dryer and expansion valve(or valves if you have two) in the trash, take the comp/clutch assy off and pull the condensor off also. now you need to flush all lines and evaporator(might have two of them) untill the flush coming out is clean and clear, could take 3 cans or 7 just depends on how dirty the system is. then you need to inspect the new compessor you put on, if it didnt get crap in it you could reuse it but i would really really be sure, will have to drain all oil from it, also check your a/c belt while you have the compressor off, if you question it just put a new belt on and keep the old for a spare, you can call the dealer and get the spec for the type and how much the system holds, then just fill the compressor with oil. now the ifffy part, if the old comp blew up and sent junk threw the lines you can bet alot of it is in the condensor, you can try to flush it out and gte lucky that you got most of it out but i dont care what anyone says-you can never get it all out of the condensor, you can take a chance and use the old one but it could push crap into the system and you will have more problems, just replace the condensor. now all you have to do is put everything all back together, never and i mean never reuse o-rings or seals, get new ones, once its all back together i would pull a vac on the system for atleast 30 mins to ensure all flush that might still be in the sytem that didnt get blown out is evaporated and removed, when that is done and holding a vac you can charge it with freon, again when you call the dealer about the oil you can find out how much freon it holds. now just turn the a/c on max in the cab and bunk and feel the cold air from the vents. no worries.

 

anything you replace on AC syatem contaminates it. when you replace the part you need you always have to vacume the system for about 10 to 30 minutes which cleans all the air and moisture out. on volvos they have expansion valve which is a mechanical part that controls the system flow to the condenser so it wouldnt freese up. the dryer is ment to trap all the moisture and contamination that gets in to the system overtime. if you done all that and it still now working than its only clogged condensor or sensors are bad. or a lot of times its that the system has not enough presure.