a/c locked up but lost no refrigerant

883 Views 26 Replies 6 Participants Last post by ehbrown1, 11 d ago

gnidlowastro

Discussion Starter · 2 mo ago

the pressure was at 150+, clutch could not turn the compressor. So I relieved the pressure, the condenser got real cold clear to the top but no loss of refrigerant, just air. I start the engine turned on the a/c and now the clutch and compressor turn, what do I do next?

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MechBob

· #2 · 2 mo ago

"So I relieved the pressure, the condenser got real cold clear to the top but no loss of refrigerant, just air. "
This makes no sense, perhaps explain better?
The clutch on a compressor is a wear item, when it wears down it can get to a point it does not clamp enough to spin the compressor shaft.

gnidlowastro

Discussion Starter · #3 · 2 mo ago

The belt was smoking and the compressor was not turning. I turned off the a/c and was able to continue on. At idle the car stalled when the a/c was switched on and the car would stall and start very hard, and make the belt smoke. The pressure was check with motor off. With motor off I lowered the pressure with a charger device and no can. No refrigerant escaped, and the condenser got colder and colder. After all of this I could turn the a/c on and it ran like normal. I do not know if the pressure "running" had went up from "0" and I did not want to damage anything. Do you have any experience with this?

Mmusicman

· #4 · 2 mo ago

You "relieved refrigerant" from the system to get compressor to work again?
You can't remove "air" without removing "refrigerant" as well.
If there was in fact air in the system, then something is wrong.

Was it overcharged? If not, then it is now clearly undercharged.
Sounds like a bad compressor.. especially when they lock up.

Reactions: 1

ehbrown1

· #5 · 2 mo ago

Something doesn't sound quite right here. From the disaster I gather, I would recommend emptying the system of whatever is in it, obviously its not all refrigerant if you have 150psi with the system off.
Open, inspect and clean the orifice tube.
Jump out the low pressure switch to run the compressor for a few seconds. If it turns with no noise or drag, evacuate the system and dial in the correct charge of the correct refrigerant and check operation.
If it does not turn and the belt squeals, replace the compressor, then evacuate and charge.
We can go from there if need be.

Reactions: 1

MechBob

· #6 · 2 mo ago

ehbrown1 said:
Something doesn't sound quite right here. From the disaster I gather, I would recommend emptying the system of whatever is in it, obviously its not all refrigerant if you have 150psi with the system off.
Open, inspect and clean the orifice tube.
Jump out the low pressure switch to run the compressor for a few seconds. If it turns with no noise or drag, evacuate the system and dial in the correct charge of the correct refrigerant and check operation.
If it does not turn and the belt squeals, replace the compressor, then evacuate and charge.
We can go from there if need be.

Yep.
"Let the air out but not refrigerant"????????
Makes me wonder if system was flat, and someone overcharged it with parts store/walmart "quickie" cans.

chevymaher

· #7 · 2 mo ago

Sounds to me like the compressor got slugged. That means it had liquid refrigerant in it.

Reactions: 1

ehbrown1

· #8 · 2 mo ago

If a compressor is flooded with enough liquid refrigerant, it will either lock up, blow the valves or snap the crank if it continues trying to turn.
If lucky enough, it just locks the rotating assembly and lets the clutch or belt slip without destroying the compressor. Liquid cannot be compressed so something has to give.

The only way that would happen is if it is EXTREMELY overcharged or someone tried charging liquid in the suction side with the system running or dumped liquid refrigerant into the accumulator with the system off. When restarted, that liquid flooded the compressor.

If it locked before damage occurred, once the liquid is evaporated or removed, evacuate and charge the system correctly and it should resume normal operation.

Since you had 150psi with it off, you are either overcharged or there is air in the system or more than likely - both.

There is no way to let air out without letting refrigerant out.

gnidlowastro

Discussion Starter · #9 · 2 mo ago

well, all that make sense; did the "Walmart fix", Ifollowed all the instruction including Utube lessons, it ran and cooled for at least a year. I can't understand why it would suddenly lock up after running many hours without a problem. I heard there is a shut off if there is no refrigerant in the system. took it to a shop and they evacuated it, that would explain why the clutch is not engaging the compressor. The shop quoted me over $2000. to fix it. I am in the process of restoring but, what now.

gwd

· #10 · 2 mo ago

Sounds by the price of it they will probably just install all new parts and fill it it up with fresh R134.
Just go to RockAuto and see the prices for 3 main easily accessible parts plus the hose/pipe items.
They will probably leave under dash and most of rear parts as is unless they detect a leak after assembling the new parts.
Most of the items total, including Freon/R134a will be under $1000.
The other 1000 is for profit.
The above part is for labor and tax.

ehbrown1

· #11 · 2 mo ago

Might be a good idea to find the actual problem rather then replacing everything and hoping for the best.

Simple check. With the engine off, turn the outer ring of the compressor and see if it turns. If it does, compressor is probably good. If not, probably locked up or close to it.
Next check, with the engine running temporarily jump out the low pressure switch with a wire or cotter pin and see if the compressor engages. If the compressor turns and is not noisy, move on. If it doesn't turn - you have a wiring problem. If it turns and is noisy, bad compressor.
If the compressor is good, open and check the orifice tube. Check for junk clogging the screen, That checks out?
Close the joint at the orifice tube and pressurize the system with just air 100PSI is good and check every joint with soapy water for a leak (also compressor shaft seal). If you find one, replace the bad o-ring and retest. If the compressor shaft seal, replace compressor.
No leaks? With that same air in the system, turn on the ac and see if the compressor engages on its own. Only for a second or two with air in the system. Compressor works?
Then go to parts store that rents tools and get a gauge set and vacuum pump if you don't have any. Most rent them for a few bucks.
Connect the gauges, evacuate the air and vacuum the system down for 2 hours.
If you have to use little cans to charge, it's no biggie. If you know what you are doing, you can do nearly as well as we pros do. (NEARLY)
When hooking up the can, allow a small amount of refrigerant (vapor) to purge the hose as you connect it. Not much, just a little puff to purge air out.
Charge the system to the correct amount and check operation.

If you did a quickie and it worked for a while, there is air in the system. When you run a system with air in it, you increase the operating pressures and reduce the efficiency of that system. More than likely, you have a leak.

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gnidlowastro

Discussion Starter · #12 · 2 mo ago

I appreciate the help and that you did not make me feel like an idiot --- like many of the others. You obviously read my comments completely before replying; thanks!!! I will let you know what happens

ehbrown1

· #13 · 2 mo ago

Just because one does not understand or never had the experinence doesn't make one an idiot.
When someone explains it to you, you nod your head, say you understand and do exactly the opposite, that's an idiot.

Good luck !!!

gnidlowastro

Discussion Starter · #14 · 2 mo ago

ehbrown1 said:
Just because one does not understand or never had the experinence doesn't make one an idiot.
When someone explains it to you, you nod your head, say you understand and do exactly the opposite, that's an idiot.

Good luck !!!

ha ha Ha!

ehbrown1 said:
Just because one does not understand or never had the experinence doesn't make one an idiot.
When someone explains it to you, you nod your head, say you understand and do exactly the opposite, that's an idiot.

Good luck !!!

Does anyone make a rear a/c block off kit for 1997 Astro van?

Mmusicman

· #15 · 2 mo ago

gnidlowastro said:
Does anyone make a rear a/c block off kit for 1997 Astro van?

NO.. because MOST people would never do this.
You have to HACK it to disable it

ehbrown1

· #16 · 2 mo ago

There is no kit as most love having it.
If you want to eliminate it, just get the two lines from a non-rear AC model and change them out. Much easier and won't leak. Don't use the stupid plug fittings they offer.

gnidlowastro

Discussion Starter · #17 · 1 mo ago

ehbrown1 said:
There is no kit as most love having it.
If you want to eliminate it, just get the two lines from a non-rear AC model and change them out. Much easier and won't leak. Don't use the stupid plug fittings they offer.

Yes sir!
Already figured that one out and pick the part up today. I am having trouble getting the white nut loose on the collector (left side from the front) any Ideas?

ehbrown1

· #18 · 1 mo ago

At the accumulator or the orifice tube? The accumulator nut can take time. Either one takes patience some times. When aluminum is in contact with aluminum for extended periods of time, they like to stick together. Spray a little PB blaster on the joints and let sit for an hour or two. Still tight? Wait a little longer and If not already, USE TWO LINE WRENCHES to break them loose. You should then be good to go.

Once you get them apart, put a little never seize on the rotating nuts to aid in assembly and disassembly in case you ever have to take it apart again.

Reactions: 1

gnidlowastro

Discussion Starter · #19 · 1 mo ago

You have bee a great help; thank you

ehbrown1

· #20 · 1 mo ago

You are quite welcome. Anytime.

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