Are there any a/c compressor alternatives to that famous and cursed R4?(W126 1981-1985)? I wonder if one of those Seltec or Unica A6 styles could work? They make one with a two groove pulley clutch for regular belts. I know I would need a different mounting bracket/manifold hose/condenser-how about a bracket/hose/condenser off a 1986-87 300SDL? (inline 6 same as inline 5?)

Ackits has the universal Seltecs/Unicas for less than $200; they offer; heavy duty-quiet operation, long life-integrated oil sump. The one on my 1993 W124 is a workhorse!

R4 problems;

1) Bad oil circulation-the R4s I have been through (5) the stamped X (between the clutch and the compressor body-marks the oil dispersement hole) is on the bottom near the ports and gravity keeps the oil from circulating to other areas and shortens compressor life.

2) New R4s suction/discarge GM style washer seal issues; hello jimmyL crushing a/c developement!, tangofox...many others, I read the many forum searches on this topic; My car, the manifold hose has an insert on the discharge, flat on the suction, manifold block is straight across, not warped; I have tried; green discharge, red suction (jimmyL W123) was slanted-terrible hissing leak, next green discharge, yellow suction (no insert) leaked, last month; green discharge, yellow suction with my homemade copper insert jb welded and tapped, leaked. I tried installing washers/seals with cfc nylog and another time dry, made no difference still leaked both times.

My new R4 (GM style seal washers) purchased 4-3-6 from Ackits (actually made/rebuilt? by B & T Champion Parts, Inc. Port Richie, Florida) $298 running on R12 and Castrol 500 visc mineral oil is now toast after 6 months.

3. Rebuilt R4s (hey at least you get the o-ring suction/discharge) Here is what I have gone through in the last 6 years all using R134A (before I knew better); GM Harrison, Four Season, Factory Air, Apco. All lasted about a season.

So now I am again planning on my anual spring time W126 a/c project. Is the A6 style Seltec universal compressor possible? If not I will probalby go with a rebuilt Behr R4 ($148) with the o-ring ports, R12, mineral oil, the usual flush-this time I am going to drill out one of my many used expansion valves. new rec/dryer, new expansion valve, rebuilt a/c hose....possible condenser, my electrical switches are 6 months old, so probably ok.

Sorry for the long post, had to inform/vent/seek advice!
Thanks

__________________
1993 Mercedes Benz 300D 2.5 205K (ex wife's)
1984 Mercedes Benz 300SD 320K (SOLD)
2004 Mercedes Benz C240 75K
1995 GMC Sierra 2WD 5.7L 188K
1983 Mercedes Benz 300SD 239K (SOLD)
1987 BMW 325i 220K (SOLD FOR SALVAGE)

609 Certification

For heaven's sake. Call AC Kits or AC Source and get a GOOD suction side filter for this go-round.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Yeah i thought about a filter but how/where to attach to the manifold hoses? And oh yeah I thought/am thinking of calling ackits to see about a warranty/return on the NEW R4 but I would probably get the same sorry GM seal washer compressor.

__________________
1993 Mercedes Benz 300D 2.5 205K (ex wife's)
1984 Mercedes Benz 300SD 320K (SOLD)
2004 Mercedes Benz C240 75K
1995 GMC Sierra 2WD 5.7L 188K
1983 Mercedes Benz 300SD 239K (SOLD)
1987 BMW 325i 220K (SOLD FOR SALVAGE)

609 Certification

ackits and acsource has an in line "high side" filter. where would it attach? would I have to splice rubber hose and have fittings made? could it go between the hose and condenser connections? how would it effect a/c pressures? seems like the extra resistance could make the high side pressure more.

__________________
1993 Mercedes Benz 300D 2.5 205K (ex wife's)
1984 Mercedes Benz 300SD 320K (SOLD)
2004 Mercedes Benz C240 75K
1995 GMC Sierra 2WD 5.7L 188K
1983 Mercedes Benz 300SD 239K (SOLD)
1987 BMW 325i 220K (SOLD FOR SALVAGE)

609 Certification

The high side filters on there website look nice, but there are low side filters for the low side that go right before the compressor intake. You would have to call Warren or Tim at those sites to hear what they might have.

There is an AC Delco filter/screen made specifically for the A/H6, R4, V5 series that "presses" in the suction port. I'd try to find one, given the history. Thorough flush goes w/o saying.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Thanks for replys jba, not trying to be a na-sayer but what good does a low side filter do? The discharge high side is where all the black death compressor crap will will go in the event of failure. So many a/c questions like;

Flushing Question; all the commercial flushes like FCJ, Interdynamics, Castrol says they are for all oil types, but they are ester based and would be fine on an R12-R134A conversion, but if I am staying with R12. I am wondering about pag/ester residue from this type flush.

Flush Gun Question; would like on of those $34 Robinair flush guns that you refill and use shop air. Are they only good for ther above type flushes? how would they work with say a semi-flamable like minreal spirits? May just use the good ole brake cleaner, mineral spirits, laquer thinner, acetone, finish up with the brake cleaner. and forget the commercial flush and gun.

R12 Mineral Oil Question; does anyone know of a good true synthetic mineral oil? Not the ester based like BG Frigiquiet; but a true mineral oil based synthnetic.

I love the challenge of a/c work!!!!

__________________
1993 Mercedes Benz 300D 2.5 205K (ex wife's)
1984 Mercedes Benz 300SD 320K (SOLD)
2004 Mercedes Benz C240 75K
1995 GMC Sierra 2WD 5.7L 188K
1983 Mercedes Benz 300SD 239K (SOLD)
1987 BMW 325i 220K (SOLD FOR SALVAGE)

609 Certification

Reason for low side filter:
What's the ONE component (where something could hide) that almost NEVER gets replaced after a compressor failure?

The evaporator. Even though the TXV will catch most debris; it's not like the orifice tube/accumulator systems which actually have a screen at the OT. I'd put on the screen that Delco makes for the R4 compressor inlet, with the history of your compressors. As components go,the condensors trap the most crud, true; but they can be changed. It's a loop system so you're right, high side filter is the most common, but low side filters (permanent or, often, temporary) are used.

Flush materials have many proponents/opponents, but the last flush needs to be really volatile. Safety, though.

HeCat is a great way to flush; For the DIY, Robinaire type gun is #2, air driven suction nozzle #3, pouring the flush in.. #4+.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)