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Two bad new AC compressors

G

Goose57

Well-Known Member
Messages
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Location
Eureka Mo.
Hi all just trying to finish up my Optimizer build but I can’t get a good compressor. Bought 2 new Murray compressors and both were bad, What are the odds of that. Both of them started screaming right out of the gate when I jumped the pressure switch.


The first one I didn’t let it run long. Maybe got a half can of freon in after I pulled the system down and checked for leaks.First thought it was the clutch and coil causing the noise but when it drained the oil from the compressor and there was a small amount of black oil mixed in with the rest of the oil. That’s when I decided it wasn’t the coil bearing making the noise. Pulled the orfice tube and it was luckily clean. May it didn’t get to the condenser. New Evap. and condenser, dryer and orfice. Got a new compressor warranted from O,Reillys and made them give me some flush and the flush tool. Had to repair the flush tool because it leaked.🤯 Flushed the system ( it wasn’t very dirty) and pulled it down, jumped the pressure switch and it too started screaming right away WTF🤯.
Both of the compressors came w/3oz. of oil in them and I topped them off at 8 oz. the required amount as per the paperwork.
I let the second bad compressor run longer getting almost 2 cans in while trying to figure out what’s going on. In the above video the belt was chirping on start up without the compressor running and went went away when I disconnected the vacuum supply to the boost switch. Then when I jumped the ac switch it got louder. Strange🤔. The second video below is after I ran the compressor longer and the chirping turned to screaming. Pulled the compressor again🤯 and the oil was a lot blacker but there was less oil compared to the first compressor. I did let it run longer so maybe the oil did get to the condenser. Both videos are of the second compressor only. Anybody have any problems w/ Murray (Four Seasons) compressors? Any suggestion on a different make of compressor they’re probably all from China. Maybe I’ll try a rebuilt one. Thanks guys.

 
That is a tremendous amount of belt jumping around in the first video right from the beginning.

Im no help on who makes good ones currently. I am 90% of the way to scrapping my factory system- hummers uses mostly gm parts but interior is horrible layout with horrible evap. I seriously might end up with a coleman rv unit on my roof.
 
in your first video even without the compressor running that belt is very loose and floppy!

with all ac systems new or reman, I always try to add a little oil in the ports of the compressor and rotate it by hand. you should not need to "jump" the pressure switch at any time when filling the system. you should be able to dump at least 90% of the first can in to the system under vacuum without the engine even running. as for adding oil in the system. after a full flush and making sure it's fully dry and empty of all flush, I always take the 8 ounces of oil and distribute it between the accumulator, condenser and lines where I can get it in while the system is still open. never dump it all in one component. problem with that is when the compressor sucks that oil in in a gulp it can "hydro-lock" the compressor braking the reed valves or blowing out the teflon rings around the pistons. same goes for when filling after you discharge that first can while the system is off, let the rest go in slowly watching the clear glass on your gauges so you don't flood the compressor with liquid. that and the "gulp" of oil will instantly kill the compressor.


first thing first... check the belt tensioner to make sure it's putting enough tension on the belt. Then on the warranty... they might warranty it out for the third time, but most places will look at you and deny the third time thinking it's something with the vehicle and not a bad batch of compressors.

if they are willing, have them order the new one but from somewhere else other than their shelf or their same distribution center. it's very possible that they have a bad batch on their hands or those compressors have sat on the shelf too long and have internal aluminum corrosion (could be from being in a high humid warehouse)

one thing to note: if you are using one of those "ez-fill" hoses with the plastic connections just for the low side, get you a set of real gauges. also if when you go to dump the first can in with the engine off and it seems to go in too slow, replace the valve cores. especially the high side if it has GM's infamous rubber ball valve. those dam things are junk and are a guaranteed leak point. order you some replacements off the jungle site or from the auto parts that have real valve cores in them. and I'm sure you already know, don't EVER OPEN the HIGH side port (red knob) on the gauges with the engine running. you can open it during evacuation and pulling vacuum but that is it else risk BOOM goes the can in your hand and a trip to the hospital!

I'm sure you already knew that but I have to mention it, it's the things I have seen in my years working at an autoparts, things people do out in the parking lot!
 
BTW 8 oz is what the compressor and auto parts say to add. your truck might need more. I don't have the specs nor do I have the factory charge sticker anymore ether. GM and their infamous wisdom put that sticker on a disposable part a-top of the acumulator. Why they did that IDK. they should have put that sticker on the hood or rad support like all the other mfg's did.

iirc my 95 truck being a 3500 CC seems to be happy with around 40oz of 134a and 8-9 oz of pag oil. Ester oil is find as a universal oil but in some climates it too gets thick in cold weather and viscosity changes wildly with temp changes I can't remember if I used pag 100 or 150, but that depends on how hot of a climate your in too.
 
Thanks guys I’m at a loss on this one. The guys a the parts store are going to think I’m nuts. I can’t count on how many compressor replacements I’ve done. The four seasons paperwork said my truck 95’ ext.cab Denso comp. 32 oz a134 and 8 oz pag 150 oil. I agree the belt is sloppy I do remember changing the tensioner before, but after the first compressor I went ahead and picked up a new one and installed it with the second comp.
and it still looks loose. I’m at a loss. I did find a previous video (a while ago) of my truck running w/ the original comp.
on and the belt isn’t flopping. It was free wheeling I wasn’t trying to charge it at that time but it still wasn’t flopping and the previous tensioner was on there. I definitely need to figure this out before the next comp. Installation. Going to check the belt routing. I was using the belt diagram from the red 95 C/K manual but I do remember having trouble. I ll have to recheck. Maybe put the previous belt tensioner back on. I do believe there is a belt problem causing all that noise but would that cause the black oil come out of the compressor? There was not a lot of oil in there compared to the first comp. I believe unfortunately the rest is in the system because I ran the comp. longer.
My plan if I get another comp. A different make maybe even rebuilt:
Get the belt tension figured out w/ the comp.free wheeling
Flush Evap,condensor and lines
Check orfice tube
New valves in the lines
Let everything dry overnight
Add required oil in comp., condenser and lines. (8oz is not a lot of oil)
Let comp. sit upside down to get the oil to the front seal. ( as instructions) did that the previous times.
Rotate comp. by hand 10x ( as instructions ). Did that also.
Then try it again.
When I check the orfice and if the dirty oil got in the condenser maybe get a new one because I’ve read somewhere that this type of condenser is hard to flush. Did I miss anything? I’ll report back.

IMG_0291.jpeg
 
Do you still have your factory GM belt tensioner? the pulleys on the auto parts units are narrower, not sure on the diameter though. what is the part number on the belt you have on there. I have seen where some auto parts catalog's reference the incorrect belt. Belt should be a gates K06120HD or a 102" 6 grove belt. There is a gates K061015HD which is a 101.5" 6 grove belt shown on RA that also fits a 95. I assume that comes in if the alternator has ever been replaced and the owner didn't save on the original pulley which is larger diameter for the tach to read properly.

When you have the belt off, check all the other pulleys for resistance. the only one you will have a slight resistance on is the vacuum pump but it also should not be very tight to rotate by hand.

Here is the belt routing for the 95
6.5 Belt Routing.PNG
 
One thing I forgot to add is check and inspect your crank pulley and balancer. if the rubber is wearing out on the pulley, but hasn't given way yet, this can also cause a belt to bounce around too.
 
Hey guys I did have the belt on the wrong side of the vacuum pump pulley. Sure making a lot of work for myself. I’m getting too old for this shit. All that chirping and screaming was probably the belt slipping, my bad🤯.
I went back up to the parts house and there going to get me an AC Delco warranted compressor. That first compressor I didn’t run long might have been good but it did have a small amount of black oil in it. I guess I got lucky they didn’t question it. But they didn’t question the second one probably because I showed them that black oil in that previous picture. I did pull the orfice tube and it was covered in black oil. I figured that it got to the condenser. I’m not sure what I’m going to do about that. The compressor coming Friday. I’ll get back to you guys.
 
Ok- but as pointed out above: DO NOT bypass anything to force the compressor on.
Evacuate, flush, disperse the oil across the different locations, charge it and let the compressor come on when it should. Forcing the compressor will damage the new compressor because the oil isn’t properly circulating yet. & when you force it on you push out the oil but there is no circulating oil throughout the system which is in suspension with the refrigerant.
 
Will L. said:
Ok- but as pointed out above: DO NOT bypass anything to force the compressor on.
Evacuate, flush, disperse the oil across the different locations, charge it and let the compressor come on when it should. Forcing the compressor will damage the new compressor because the oil isn’t properly circulating yet. & when you force it on you push out the oil but there is no circulating oil throughout the system which is in suspension with the refrigerant.
Click to expand...
Thanks for reaching out William. That is a good suggestion. I will even if it takes all day. It might not take that long mine only takes 2 1/2 cans 32oz. I can’t tell you how many times I’ve jump compressors to get the flow going with problems. I probably did that back in grease monkey days we were on time and materials lol😎 I hate to ask but what’s your opinion on flushing the condensser? I thought I read somewhere that gm recommends closed loop flush w/ 134a not chemicals. Probably because of today’s condenser make ups. Hell the Evap is problem like that🤯. Thanks again.
 
Goose57 said:
Thanks for reaching out William. That is a good suggestion. I will even if it takes all day. It might not take that long mine only takes 2 1/2 cans 32oz. I can’t tell you how many times I’ve jump compressors to get the flow going with problems. I probably did that back in grease monkey days we were on time and materials lol😎 I hate to ask but what’s your opinion on flushing the condensser? I thought I read somewhere that gm recommends closed loop flush w/ 134a not chemicals. Probably because of today’s condenser make ups. Hell the Evap is problem like that🤯. Thanks again.
Click to expand...
I have used the flush stuff inna can on my old clunker~junkers and then did a diuble rinse with lacquer thinner, blowed them out good with compressed air and never hadda problem.
Before the lacquer thinner stage I would band several layers of white rags over one port of the evaporator then blow air into the other port to make sure it was clean, then pour in some lacquer thinner and bliw it dry.
Condensers, i always replaced those. Not worth the risque of having crap hung up in those.
 
Flush in both directions. in the past I always used brake cleaner but the kind that dries fast. only don't flush the accumulator, replace it. the thing about the condenser, if you can blow through it one way and it seem free flowing but builds up pressure in the other direction, that means there is a restriction of some kind in it and it needs to be replaced.
 
Goose57 said:
I agree the belt is sloppy I do remember changing the tensioner before,
Click to expand...
Goose57 said:
Flush Evap,condensor and lines
Check orfice tube
New valves in the lines
Let everything dry overnight
Click to expand...


The tensioner for 1995 and older engines have to deal with the compressor load on the belt so they have a stronger spring than the 1996+ engines that have the compressor on the driver side of the engine. As above verify belt routing and proper length.

Aftermarket doesn't F'N get it and they all use the weaker 1996+ spring tension for the 1995 and older engines. At least around 2010 when I had a problem. (Check a 1998 and 1993 and see if it's the same part number? Aka OOPS! if it is.) I couldn't hardly get the compressor to start turning in our heat without the belt screaming. I ordered one from a GM Dealer.

Do you have the fan shroud? It's missing in the video.

Are you using compressed air to "dry the system" of the flushing agent after flushing? "Dry overnight" Not how it's done. You can't have any "solvent" left in the system. As above you flush the system without the compressor or accumulator in the system.

Are you using a vacuum pump to pull the system down 30 min (to a couple hours) before charging?

At this point the system is contaminated. Replace the condenser again.

Good to learn how to DIY, but cheaper to hire a shop and one and done esp. figuring your time.

FWIW the R4 compressor was a POS on R12. Worse with the higher R134A pressures. They leak and then run low on refrigerant. Low refrigerant means poor to no oil return. Like a 2-stroke engine the R4 depends on a steady oil flow to live. There are tougher compressors out there that can live with low refrigerant charges, but, not this one. Low charge means quick death and quick system contamination.
 
I agree on that. the R4's are junk from the get go. On my 93 since the pressure switch threads are standard SAE and not metric, I opted to install a pressure switch that fits to old mid 80's rigs. they are adjustable so I could get it to cycle at 15 psi rather than the 22 psi from factory. then charged the system with R152a AKA office duster cans. it's pressures are very similar to R12 and cools better than 134a just not as good as R12.

I got really lucky with it since the system had been open with the accumulator missing since 2009. flushed out the system and charged it up. it hasn't leaked a drop even with the compressor it had on it!

I could have left the factory pressure switch but opted to go that route in prepping it to be converted to enviro-safe AKA propane/butane refrigerant. Since it hasn't leaked nor stopped working, I've left it as it is. figured when the compressor shitz the bed, I'll replace, flush and finish converting it over. Texas heat is something else with the high humidity. Will's area is hot too but dry. humidity plays a huge part on how AC's will perform.
 
I don’t remember when the change over happened for the non-flush evap. I look it up each time which are flushable and which are scrap metal.

My preference changes based on how good the overall system works. Gm trucks always seemed sub par, so adding the newer style ones help it run cooler.

But no matter what- the best option is thermal coating the evap & condenser. 30% improvement is massive. The type that TSP coats with is the best when its cured in a kiln. But the air cure type isn’t far behind.
 
Will L. said:
But no matter what- the best option is thermal coating the evap & condenser. 30% improvement is massive. The type that TSP coats with is the best when its cured in a kiln. But the air cure type isn’t far behind.
Click to expand...

To the OP my signature line details the TSP condenser I put in my Dodge Cummins. Money well spent! But after you get the system working…
 
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