Two bad new AC compressors

[Goose57]

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.

 

[Will L.]

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.

 

[dbrannon79]

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!

 

[dbrannon79]

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.

 

[Goose57]

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.

 

[dbrannon79]

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

 

[dbrannon79]

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.

 

[Twisted Steel Performance]

I'm no expert but I don't run the compressor till I am almost done filling, then I run the compressor on and off several times to slowly get stuff circulating...

 

[Glagulator]

Looks like the belt is on the wrong side of the vacuum pump in the 1st video.

 

[dbrannon79]

Good catch @Glagulator I had to go back and look, sure enough it does look that way.