Automotive Air Conditioning Information Forum (Archives)

Provided by

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

Compressor locking..update

Underdog on Fri August 01, 2008 8:53 AM User is offline

Year: 1986
Make: Chevrolet
Model: Celebrity
Engine Size: 2.8
Refrigerant Type: 134
Ambient Temp: 85
Pressure Low: 40
Pressure High: 175
Country of Origin: United States

I installed a reman HR6 compressor on this Chevy. Also new acumulator, blue orfice tube, all the o-rings. The original compressor turned smoothly and worked fine but was leaking. Since I couldn't find anyone local to reseal it I went for a reman. The original orfice tube screen had a small amount of debris at the base of the screen, less than an 1/8 teaspoon I would estimate. Nothing that would indicate the original compressor was failing. I blew everything out with 150lbs of shop air holding a white rag on the other end of the heat excangers and didn't see anything. I drained the oil out of the reman, and added 8 oz of ester100 puting a couple oz in the compressor and the rest in the evaporator and acumulator.

The system vacumed down well. I started to charge with one can of 134. At around 65 lbs the comp started cycling quickly of & on as I would suspect with a low charge. But, by the time I had one whole can in and started the second, the clutch started to slip on engagement. It progesively got worse and I can't turn the compressor by hand. It was tight out of the box but I have been told that is normal. I could turn it by putting the clutch in a vise and rotating the body. It did have a tighter spot on rotation.

When it did cycle, the low would go down to about 40 and the high to 175. So my question is, did I ruin this compressor or was it junk out of the box. It's hard for me to believe the original compressor worked fine and still turns but this one would fail in 10 minutes.

BTW, this is the 4th compressor I've ordered before getting the correct one. Wish I'd never attempted this project.

Edited: Sat August 02, 2008 at 7:30 PM by Underdog

TRB on Fri August 01, 2008 10:41 AM User is offlineView users profile

What brand of reman are you using?


When considering your next auto A/C purchase, please consider the site that supports you:

iceman2555 on Fri August 01, 2008 11:44 AM User is offlineView users profile

This event is not uncommon.

The problem is not that the compressor was 'tight'....difficult to rotate...these are 'normal' conditions of a new or properly reman'd GM H or R series compressor. The issue with a tight spot are also common to rotation of the unit by use of a spanner wrench or clutch turning tool. The idea of putting the clutch in a vise and then rotating the body....gotta add that one to my list of methods......
The problem encountered is more that likely a compressor that has starved for lubrication. Adding a small amount to the compressor....some in the accumulator....some in evap are not the most advantageous conditions.

During the start up and recharge mode being used...the compressor may actually pump itself dry of lubricant and become noisy or actually lock up. The compressor that you are currently using is more that likely already 'trashed'. Get another compressor....suggest to 'bite the bullet' and obtain a new unit...but it really makes little difference if the system is not prepared and recharged properly. The use of ester (POE) is not the specified lubricant for this system....the true spec is for a PAG 150. This is a bit heavier lubricant. However, the POE/ester 100 will is just a 'lighter' lube.

If it were my vehicle, I would flush the system once insure a proper lube recharge and lubricant condition. Check the orifice.....replace if necessary. If the system is not 'open' for a long period of time....use the same accumulator...simply drain the lube and replace as note below. This will result in a possible slight overcharge of lube....perhaps...2 oz...but this should not be a problem.
Add lubricant to the compressor....3-4 oz.....three is sufficient. Add the remaining lubricant, 5 oz, to accumulator. Simply introduce the lube into the inlet (evap) side of the accumulator. The amount of lubricant in the accumulator should provide sufficient lubricant flow to the compressor during recharge. The problem is that charging by cans....does not allow for sufficient refrigerant to insure complete lubricant flow for the system during the recharge procedure.

The conditions that were described in this post have simply moved the lube from the compressor back to the evap. The amount added to the accumulator....2 or 3 oz was quickly absorbed into the desiccant bag. The lube added to the evap has remained there...not moving back to the accumulator to allow flow back to the compressor.

The increase in lube within the accumulator gives a 'cushion' for the system to maintain lubricant flow to the compressor.

Evac the system.

Start the vehicle and allow the engine to come to normal operating temperature. Engine at idle....doors open....max cool....disconnect the LPCO from the wiring harness. Make a jumper...a paper clip will work great. Use the jumper to activate the compressor by simply jumping the wiring harness terminals. This should be done after adding the first can of refrigerant. This will allow for constant compressor operation and aid in charging the system.

The recharge mode begins....get as refrigerant into the system as quickly as possible...operation of the system with a undercharge will result in repeated compressor damage. Charge the first can as a 'liquid' into the suction side...right into the accumulator.....the heat from the engine and a warm accumulator will boil this refrigerant into a vapor almost immediately. When adding the second can (charge as a vapor) this can in warm water ...this will force the refrigerant into the system more quickly. The idea is to get the system recharged as rapidly as possible...and the system must be charged completely...or the compressor is going to fail once more.

The problem with retro fitting is that charging by pressures is not a viable charge method....134a operates at a much higher pressure and the 12 system is simply not designed to handle this pressure.
MAX COOL...HIGH BLOWER....ENGINE @ IDLE....DOORS OPEN....charge until the inlet and outlet temps of the evap are the same temperature....or within 3-5 degrees of each other. This will insure flooding of the evap and a full system recharge.

Check pressure....and if desired....elevate engine rpm and recheck pressures.....if a high side pressure problem exist...and it may....DO NOT REMOVE refrigerant to 'balance' pressures.....the excessive pressure condition must be addressed with additional air flow adjustment.

Reattach the LPCO....and test system for proper LPCO operations. Evaluate system and post result.

Good luck!!!

The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Underdog on Fri August 01, 2008 1:22 PM User is offline

Tim, it is an Arctic Air. I first ordered a new one from you guys but it was clocked together wrong. You guys did come up with the correct one but it was 466 bucks. 2nd one came from the local parts store (4 seasons) it was clocked right but missing the main mounting lug. Tried another online source & got another clocked wrong. They had me email pics and I finally got the one I have now which at least bolted up.

Iceman, First of all, thank you for the detailed reply. The clamping in the vise deal wasn't my idea. AMA told me to do that when I complained about the first new one being tight. I did pull the new orfice tube and it had a few small specks of aluminum on it. There was lots of oil on it and dripping out the line. My decision to use the ester was from reading I did here that gave me the impression it was the best choice for a changeover. Maybe not. I plan to pull the compressor back off tomorrow and see if it is really locked and what runs out of it.

Thanks again, Jim

Underdog on Sat August 02, 2008 3:39 PM User is offline

Well, I got the compressor off today. Turns out it isn't locked up. Actually, I can now turn it with a 3/8 ratchet on the clutch nut. It apeared to have oil in it but not enough to run out when turned upside down. The one port has a light black coating on it similar to the original one I took off. No signs of metal. I poured some oil in it and turned it. It pumped the oil out the discharge. What came out was darkish grey in color but absolutely no metal particals.

The outfit it came from has agreed to warantee it as long as I have an invoice for the new accumulator. I really hate to go through the hassle of returning it though if there isn't anything wrong with it. Especially since it took four trys to get one that fit. I have a local A/C guy that will flush the system for 50 bucks. I have a bodyshop and he & I have done bussiness in the past so perhaps that's why he agreed to do it. Another acumulator from AMA is only 15 bucks so at this point I wouldn't have a problem with getting another.

So my questions, Should I get the ester all out of it and go back to the PAG as Iceman sugests? Does this compressor sound trashed ?

Another problem I didn't mention in the first post (as it wasn't relevent) As I ended my failed attempt at chargeing it, I heard a hissing sound. The line coming out of the accumulator has a hole in it now. My father had an aftermarket cruise control installed when we got this car some 20+ years ago. They ran the cable to the carb under the aluminum line and over the years it wore into the line. I don't think it was leaking until the presure started to build since I never would have gotten it to vacuum down. It's right on a curve in the line so I don't think a union will fix it. Anyone had luck with the aluminum brazing rods? Years ago I used them on an aluminum hood and know it's pretty tricky.

Thanks for listening to my nightmare.. LOL Any opinions or sugestions are greatly appreaciated.


iceman2555 on Sat August 02, 2008 7:51 PM User is offlineView users profile

A personal preference is for PAG...however, others on this site have used POEs with success. The amount of lubricant removed from the compressor is insufficient to maintain properly lubrication for the compressor. The evidence of dark lube may be traced to possible piston seal (teflon) damage. Could be a possible lube over heating condition, but this is doubtful.
Since the compressor was 'locked' at one time....and the low amount of lubricant removed from the unit.....the possibility of internal damage that may have already occurred.... a suggestion would be to replace the unit now....a possible savings of refrigerant and labor at another time.
If you are going to have the system flushed...please....please...ascertain the type of flush this shop prior to having this done.....there may be some suggestions we can offer to prevent another possible problem......there are flush chemicals available...and procedures that a DIY'er may be able to accomplish that may possibly be more advantageous that those this shop uses.

The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.