A/C help please

[jerrymp]

My a/c had a leak and all the r134a was gone. Had to replace the high side input valve. So that fixed the leak. Prior to finding that the leak was present, had a shop put in coolant and they put gauges on it and with coolant, had high side reading of 300 to 350, just sitting there at idle. Would go down to 250 or so at 1500 RPMs. After fixing the leak, and evacuating the system, a well meaning friend figured we ought to put oil back in the compressor so we added 4.0 oz. I think that was likely a mistake because could only get 12 oz coolant in before the high side pressure got up into the 350 range. Also replace the orifice tube at the same time. It was covered in what appeared to be baked on black crud. At this point, going down the road on an 85 degree day, I get 45degree air out the vents, but at idle at a stop light, temp spikes up and the system goes into "max" which I have read is a symptom of excess high side pressure. So, my analysis is that I got too much oil in the compressor. I have not been able to find a way to remove any of the oil. So, I guess my next step is to replace the compressor. What do you think?

I know that if I replace the compressor, I have to replace the dryer/accumulator/dehydrator aluminum can on the firewall. Would appreciate any helpful how-tos on removing that litttle thing cause I don't want to break the aluminum lines.

 

[Burning oil]

You must have been typing this as I posted my thread on A/C.

You can recover the 134 then blow out the system with compressed air. You may need to disconnect each component and blow it out. The comp may need to be removed and emptied of oil? I don't know how much to put back in, but a shop manual would tell you.

When your blowing out the system you might as well get some A/C flush and do it right.

I was asking in my post what the normal pressures should be high and low side?

 

[fastjohnny]

I recharged mine last night after a complete evacuation. Held a vacuum. Was nice and cold. After I shut things down, I hear an annoying psssssss. Back seal on the compressor is leaking, so I ordered this from the 'bay:


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=320515473715&viewitem=

 

[Brooklyn Tow]

When I pulled my A/C hose (Top big one) off to change it, I'd say a good 3-4 oz. of oil poured out of it.......That should help you.

 

[jerrymp]

When I pulled my A/C hose (Top big one) off to change it, I'd say a good 3-4 oz. of oil poured out of it.......That should help you.

Is that the one with the built in muffler, the bump in the pipe just before the compressor?

 

[Brooklyn Tow]

Affirmitive

 

[jerrymp]

I recharged mine last night after a complete evacuation. Held a vacuum. Was nice and cold. After I shut things down, I hear an annoying psssssss. Back seal on the compressor is leaking, so I ordered this from the 'bay:


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=320515473715&viewitem=

Not to piddle on your parade, but you can get them both new for 230.00.

What about the job of R/R the dryer/accumulator? Leery of screwing up those aluminum pipes. And given my luck, I could sure has heck mess them up.

 

[fastjohnny]

Not to piddle on your parade, but you can get them both new for 230.00.

What about the job of R/R the dryer/accumulator? Leery of screwing up those aluminum pipes. And given my luck, I could sure has heck mess them up.

I got them both new/reman for $130.):h We'll see...

If the fittings on the accumulator don't budge, gently heat them with a propane torch.

 

[WarWagon]

Also replace the orifice tube at the same time. It was covered in what appeared to be baked on black crud.

This black crud is known as "Black Death". This is where the Teflon rings in the compressor melt and get thrown through the system with ground up metal parts. Fords have to replace the condenser because there is no way to get the solid Teflon out that can remelt or break free at operating temps.
Your AC compressor burned up from no oil or overheating. Check the cooling fan and clutch. Check for restrictions like the famous mat behind the oil cooler.

As your high side pressure climbs - well it is because the condenser is hot as hell. I bet you have an issue with the fan clutch or plugged air flow. Temperature of R134a determines pressure. It can take 30 seconds for the temperature to drop after the AC is turned off because gas is still condensing. Only if the low side goes low with high side pressure high then you have a restriction in the system.

Possible it was the PO's compressor that failed and improper repair.

In any case you have a severely contaminated system.

To fix it you need to flush the condenser, evaporator, and hoses. Replace the accumulator - that also has a filter in it BTW is not flushable and holds a lot of contaminates, and replace the main screen-the orface tube. Most shops like to skimp on replacing the accumulator and short AC compressor life is sometimes the result.

If the current compressor is noisy then it is the source of the contamination.

 

[jerrymp]

WarWagon

Thanks. Please define "noisy" as relates to compressor. I ask because I don't hear noise from my compressor.

Thanks guys for all the info. I think my next step is evac system, flush system, new dryer, r134 and probably no more compressor oil.

 

[Acesneights1]

The flush is a ripoff. All the stuff iis , is denatured alchohol. Can buy it at Home Depot. That's all I use in my flush gun. I agree sounds like Compressor came apart. That sucks. Yers ago the cheapskates use to bake the Accumulator in an oven and reuse it. I wouldn't. Flush the entire system. New orifice which may be a bastard to get out. They used to make a repair kit where you could actually cut the tube on the evaporator and remove the piece with the orifice and then a new section with orifice went on vi compression fitting. I actualy had good luck with those but have not had to buy one in years. Don't even know if they still make it. dryer sould always be replaced with compressor or if system has been left unsealed for any amount of time. Also as Warwagon mentioned keeping the condensor cool is paramount. I had an Old dodge motorhome years ago that was drinving me crazy. I replaced every part in teh SOB and as soon as I would try to put more than a pound of charge in the compressor would lock up at idle. I finally tried runnig a garden hose over the condensor while charging it and it worked fine so I had to install a pusher electric fan on the condensor to solve the problem.

 

[WarWagon]

WarWagon

Thanks. Please define "noisy" as relates to compressor. I ask because I don't hear noise from my compressor.

Thanks guys for all the info. I think my next step is evac system, flush system, new dryer, r134 and probably no more compressor oil.

):h You would know noisy. Sounds like marbles down a wash board.

System needs 8 oz of oil. You can pour out the oil from the compressor. As you are flushing the system... Well Oil is in everything. It runs through the system at all times. This means every part has oil in it. Flushing the system removes a lot of oil.

So pour out any oil you can from the compressor, flush the system and then add 8 oz of oil. You will then have the correct amount of oil in the system.

Too much oil is not an issue. It would stay in the accumulator. The tube in it has a small hole to meter oil to the compressor. Surplus oil would pile up in there.

Again check cooling of the condenser. You may have a plugged orface tube. Pull it out and it will be clear if this is a problem. Again check airflow and temp of the condenser...