A/C compressor woes

[Edahall]

Last year, I installed a new compressor on my 1990 Suburban. Cooling output was greatly reduced from the previous one. So today, I installed a new parallel flow condenser. I vacuum out the system and was in the process of recharging the system. Just about the time as cool air was starting to come out of the vents, I heard something squeaking and within about a minute the noise got louder and finally, the compressor locked up. What's going on here?

[Pontiac1976]

Was it sitting for a few months. clutch seized or pulley or bearing check try to free see if it spin free, If not time to change to part or the compressor complete.

[Edahall]

Originally Posted by Pontiac1976

Was it sitting for a few months. clutch seized or pulley or bearing check try to free see if it spin free, If not time to change to part or the compressor complete.

Nope, I have been using the A/C regularly and used it as recently as a few days ago. The clutch runs free but the compressor is completely locked.

[Palf70Step]

Maybe oil mixture was off in the recharge. I don't know though, that was the only thing that comes to mind.

[Pontiac1976]

Ok well.Last year you replace the compressor did you replace the O rings seals. If you did maybe check to see if the where leaking there maybe bad seal.If there bad seal maybe why. Or just a bad compressor.

[Eman]

Make sure you have good air flow through condenser. I had similar issue a few years ago. Not enough air flow and the pressure goes up causing compressor to lock up.

[Edahall]

I'm getting a new compressor shipped out to me on warranty!! This is one of those times that spending the extra $80 for a lifetime warranty is paying off handsomely.

[Richard]

In my experience rebuilt/reman compressors are junk, even with the lifetime warranty. Recommend you fork the extra cost for a new Delco unit or you will be replacing it again soon. Not to long ago took back a lifetime warranty compressor and got a full refund. Even though I do the evacuation and recharge myself. Did not want to risk it. That was actually the second time it happened to me. The cost of refrigerant and time is not worth it. I am suspect of the new parts as well. Maybe manufacturing will return to USA in the future and hopefully quality will get better.

[my86lb]

also change your orfice tube
What does the AC orifice tube do?
An orifice tube has no moving parts and contains a permanent restriction within the system. The orifice tube systems control the refrigerant flow through other means, such as cycling the compressor on and off, or the use of a refrigerant regulating valve within the compressor itself.Sep 20, 2016

[v30crewcab]

what compressor are you running? it was probably low on oil.

[Edahall]

Originally Posted by v30crewcab

what compressor are you running? it was probably low on oil.

I'm running a compressor out of a 1990 Dodge Ram. I also suspect that the old compressor died of oil starvation. When I removed it from the truck, I tried to drain the oil out of the old compressor and there was none. There was just a little bit in the old accumulator. Wonder where all of the oil went?

The new compressor came prefilled with 6.5 oz of oil. The system takes a total of 11 oz. I hope that 6.5 oz of oil that the new compressor came prefilled with is enough.

[Palf70Step]

This is what I was told and have read, that always drain the compressor of whatever oil it was shipped with, then add the recommended amount of the proper oil for the type system. I forget what the two main types of oil there is at the moment.

[Warrens69GMC]

Originally Posted by Palf70Step

This is what I was told and have read, that always drain the compressor of whatever oil it was shipped with, then add the recommended amount of the proper oil for the type system. I forget what the two main types of oil there is at the moment.

Ester and Pag (46,100,150)

[Edahall]

Originally Posted by Palf70Step

This is what I was told and have read, that always drain the compressor of whatever oil it was shipped with, then add the recommended amount of the proper oil for the type system. I forget what the two main types of oil there is at the moment.

The problem is I don't really know how much residual PAG oil is still in the system. I rebuilt it 5 years ago and put in 11 oz of oil but since then, I've replaced the compressor (which I added 4 oz of Oil) and the evaporator.

The reason that I changed out the evaporator is because the previous pump cooling output was absolutely pathetic even with the correct amount of charge. And then when I was recharging it, it took forever to draw in the freon. I must have ran it for 45 minutes and maybe there wasn't enough oil circulating throughout the system due to undercharge.

I decided to take my chances and recharge the system. It's blowing cold air now.

[v30crewcab]

I run a 94 dodge compressor on mine. I think I have 7oz of oil in my system, it takes 3lb 14 oz of 134 to charge it. I run a ford expansion valve(slightly smaller orfice) in it and it will freeze you out.

[Edahall]

Originally Posted by v30crewcab

I run a 94 dodge compressor on mine. I think I have 7oz of oil in my system, it takes 3lb 14 oz of 134 to charge it. I run a ford expansion valve(slightly smaller orfice) in it and it will freeze you out.

Ran this new compressor today and it feels much colder than the previous one.

[Edahall]

From what I understand, there has to be enough charge for oil to circulate through the system. If that is true, what keeps a pump lubricated when the system is being re-charged?

When I was re-charging the system after replacing the condenser, the compressor was sucking in the freon slower than molasses. I was about 45 minutes into it when the pump locked up. When I removed the pump, it was bone dry! Since then, I have installed a new pump and cooling performance is much improved.