Crappy R4 compressors! - PeachParts Mercedes-Benz Forum

samiam44 · #1 04-09-2010, 08:38 AM

Never had such problems..

I always dropped new ones purchased at Autozone on my car. They drop shipped them from a GM warehouse. I always used straight mineral oil- none of this synthetic stuff. You can purchase it at Napa still.
Some say the oil feed for the front brg must be rotated. You can buy a seal kit if you want to do that. Never had the sealing rings leak= perhaps the rear of your hose needs attention. Make sure all the line clamps are correctly there.
The aftermarket rebuilds tend to grenade in a short time.

The BIG question is HOW are you flushing the system and what hoses do you replace. There is a lot of metal when an R4 dies- I suspect you have bits left in the system. I'd add a screen filter and you need a professional power flushing and some component replacement to get back to a reliable system.

M

Hit Man X · #2 04-09-2010, 11:12 PM

Quit purchasing reman ones, that is your issue.

James L · #3 04-10-2010, 08:25 AM

I have purchased new ones, they do not last any longer than reman, just cost more. New ones have GM sealing washers, reman has o-rings.

The MB R4 is a bad design, On my GMC R4 the ports or up and oil feed to bearing flows down unto shaft. With MB ports are down and oil has to flow up which causes bearing and shaft oil issues.

Before, I have always flushed system before. Replaced dryer exp, ect...My compressor did not lock up,it is working. So I am going to just drop in another, vac and recharge.

I am going to drop in an Oreilly-Murray (four seasons), from texas just like the autozone one (compressor works).

One day I am going to get hoses fabricated and mounts to do a denso.

JimFreeh · #4 04-13-2010, 02:35 PM

Quote:

Originally Posted by samiam44

The BIG question is HOW are you flushing the system and what hoses do you replace. There is a lot of metal when an R4 dies- I suspect you have bits left in the system. I'd add a screen filter and you need a professional power flushing and some component replacement to get back to a reliable system.

M

First thought I had after reading the original post...

Jim

James L · #5 04-13-2010, 03:26 PM

Flushing; In the past 15 years, I have broken apart and flushed the entire system on my two W126s at least a total of four times (2 each), flushing evap, condenser, lines, replacing dryer, exp valve and new condenser, new compressor hoses, 8oz oil just like fsm, rotating 15 times before mounting., ect.

Flushing with approved chemicals and dried shop air (more than most shop do). I flushed even when compressor did not fail and was weak (as in now) also when failed, never saw any metal particles at all, just oil and dye. To really flush right you need a two way powerfull electric/air machine like the hellcat power flusher. No shops in my area ever use such a machine. Anybody here use one?

Anyway....My 1995 GMC at 198,000 miles, still has the original Delco/Harrison R4 compressor with oe 134A. Again it is mounted on top of engine with ports up (with o-ring sealing washers) (x) up and refrigerant oil flows down onto the bearing and shaft seal as it is designed.

MY current R4 on my 1984 MB is working but the the clutch/bearing is now making noise beacuse it has been starved for oil after 3 years.

I will reclaim/recycle the R12 freon, change out to the Four Season reman, look at discarge ports and hoses for any trace of failure (black death, ect) if it looks good. I will seal up, pulll a long vac, with my JB 2 stage deep vac pump with fresh oil. Then Clipligt Dry R for moisture and acid, then cliplight super seal Auto, dye/oil, and R12.

I am going to hunt up a 1986 300SDL in the salavge yard and try to fabricate a mount, v-belt pulley and compressor hoses so I can do a denso next year and be thru with this R4 crap and get better performance and lifespan.

James L · #6 04-13-2010, 04:34 PM

samiam44, screen filter? I would have to have my $100+ compressor hoses cut and fabricated for a screen filter to work.

I notice on this forum everyone wants to bash everyones flushing method and blame this for the R4 failure. In the end it may not even matter as long as you get the debris out (if it failed). Sometimes a flush is not needed if compressor does not grenade. Leave expansion valve and rec/dryer alone and button everything up real quick.