NEW R4, Seized!?!? - PeachParts Mercedes-Benz Forum

300SD81 · #1 04-05-2007, 05:23 PM

My new remanufactured R4 compressor just got here, and I cannot turn it! All the shipping plugs, etc are still on, does something need to be removed before it is turnable?

rrgrassi · #2 04-05-2007, 05:57 PM

Those compressors are very stiff, and come with some oil in them already, but that does not mean to not fill the system w/oil before buttoning it up for evacuation.

I put mine on last summer, and I still can't turn it by hand. It will turn easier one installed, but do not turn it until the lines are hooked up, as oil will flow out. Don't ask me how I learned that one!

300SD81 · #3 04-05-2007, 06:01 PM

Theres a label on the shipping plug that says "no oil" I pulled the plastic plug out for a spilt second to see if it was pressurized, but with how loose the plug is, it would pop out... There was no oil inside. Would it be ok to get one of those compressor wrench thingys with the triangle and 3 pins to turn it around with?

rrgrassi · #4 04-05-2007, 06:06 PM

Wow mine had thick clear oil and a small charge of nitrogen. It said to spin, but not to drain it. Spinning it drained it a bit.

You should be able to spin it by hand/tool. To be safe, put some oil in it before you spin it, that way it won't start up dry on initial on car activation.

300SD81 · #5 04-05-2007, 06:59 PM

Spins easily after breaking free with the wrench and putting a little oil in... Now, as soon as my expansion valve gets shipped here, I can get to work

tobybul · #6 04-05-2007, 08:05 PM

Before messing with it, I would probably call the outfit that sold you the item and ask them these questions... they should be able to tell you the state the compressor is in. This way, you won't void any warranty that came with the unit...

300SD81 · #7 04-05-2007, 08:13 PM

Going to void the warranty anyway, the warranty papers require proof that a qualified shop installed it.. thats not going to happen

mespe · #8 04-05-2007, 10:33 PM

Quote:

Originally Posted by 300SD81

Going to void the warranty anyway, the warranty papers require proof that a qualified shop installed it.. thats not going to happen

That's when you get the required proof afterwards, if you need it.

Astroman · #9 04-06-2007, 08:44 AM

I've had 2 brand new compressors grenade within 30 seconds of installation. One of them I installed, one of them a shop did the work. I'm thinking that the quality just isn't too great on them these days.

#10 04-06-2007, 09:36 AM

Quote:

Originally Posted by Astroman

I've had 2 brand new compressors grenade within 30 seconds of installation. One of them I installed, one of them a shop did the work. I'm thinking that the quality just isn't too great on them these days.

New or remanufactured?

tangofox007 · #11 04-06-2007, 11:44 AM

Quote:

Originally Posted by Astroman

I've had 2 brand new compressors grenade within 30 seconds of installation.

Were they turned by hand first?

Astroman · #12 04-06-2007, 12:21 PM

One was new, the other was a Reman. Both were shipped with oil, which was drained first. Both were installed in accordance with proper procedures which involves hand rotating, adding an appropriate amount of new oil, hand rotating some more, then finishing up with the installation.. They both cooled for 90 seconds or so before failing so it wasn't a hydraulic lock. The first time I couldn't figure out why it wasn't cooling until I took it back out, and all kinds of metal pieces fell out of the ports. So I had to buy another receiver/dryer and do a complete flush. After that I took it to an indy, let him order another (new) compressor which promptly did the same thing. Do the whole procedure again and now she's golden.. Next time I'm going to machine a new bracket and install a vane style compressor. I think if you took a poll, you'd find that half the people here have had a working compressor for 20+ years, and the other half goes through one yearly.. My '78 still has it's original which works great, so does my '82 but the '81 can't seem to catch a break..lol

#13 04-06-2007, 01:03 PM

Mine seem to last about 100K each, I've just decided that I'll be spending $1000 every few years on the AC system, about $.01 per mile.

tangofox007 · #14 04-06-2007, 02:27 PM

Quote:

Originally Posted by Astroman

I think if you took a poll, you'd find that half the people here have had a working compressor for 20+ years, and the other half goes through one yearly..

I replaced the original compressor in my '82 300D last year at 140k miles. It was still working, even after five years on R-134. (I reverted to R-12 and installed a new R-4.)

Kuhlrover · #15 04-06-2007, 03:36 PM

If i read your quote correctly, you said you tried turning the compressor while you still had the plugs in? You should crack these open so you don't have a sealed tight system before trying to turn pulley. Keep in mind this is a pump. It is trying to suck air in on one side and compress it out the other side. If you have it completely sealed and it is a tight rebuild then you are trying the impossible.

Also, drain what ever oil is in the compressor out into a clear measuring cup. Even if it is tagged "shipped without oil" I have almost always found oil in the compressors. It is a residual from the testing a remanufacturing. You will need to measure the oil going back into the system. You should also drain the old compressor and measure the oil coming out of it. If you didn't have a huge leak where you obviously lost a lot of oil, then pour back into the new compressor the new oil you drained out of it the same amount you emptied out of the old compressor. Do not use the old compressor oil.

TimK