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  #1  
Old 07-06-2003, 11:54 PM
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Join Date: Aug 2001
Location: Evansville, Indiana
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Nice cool AC

I replaced the expansion valve on the 300TE before my trip to Cleveland this weekend and recharged with R134a.

Other than flaky temp control (have to twiddle the temp dial to get proper temp once in a while, it tends to "stick" on AC sometimes, gets too cold), we were comfortable, even with six people in the car in city driving. Gets a bit warm sitting a stop lights, but this is about normal for European cars.

I also replaced the o-rings at the expansion valve -- I hope they were the only leak.

Those Firestone Affinity LH 30s drive nice, too, especially in the two heavy rainstorms on the trip!

Peter
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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
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Old 07-07-2003, 12:11 AM
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I don't know if this is an easy conversion, but I would think if you replaced the condensor and aux. fans with the 94/95 parts then you might 'solve' the not so cold A/C at stoplights!

Good luck!
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  #3  
Old 07-07-2003, 12:15 AM
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wjm wjm is offline
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That's great news. I had the same problem long ago. It is also recommended that you change the receiver/dryer whenever you open up the system.
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  #4  
Old 07-07-2003, 12:17 AM
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Join Date: Aug 2001
Location: Evansville, Indiana
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Im not THAT much of a masocist (sp?)! I'll cheerfully wait until the evaporator goes before I spend a week replacing it!

I can live with the poor cooling at idle, no different than any other car I've ever had with AC, none of them cool well sitting in traffic.

I ran a vac of 30" for an couple hours while changing a tie rod end, so I didn't bother with changing the R/D -- I'm fairly certain the water is mostly gone from the desicant with that vac (really more like 100 mTorr -- it's a "real" vac pump from work).

Peter
__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
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  #5  
Old 07-07-2003, 11:07 AM
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Join Date: Jun 2000
Location: Plano, TX
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Good job on the changeout. There's nothing like the satisfaction of a nice, cool breeze on a hot day

Changing the condenser and radiator fans isn't going to do much for idle performance on this car. The main problem is the a/c compressor - it's too small (displacement-wise) and turns too slowly. It simply doesn't "pump" enough at idle. This can be observed with a set of gauges. On my 1987 300TD (same compressor) the low side pressure rises to 45-50 at idle. (It's about 25 at 1500RPM, which is just where you want it.) Evaporator temperature is directly related to low side pressure - with R-12 it's pretty much the same as the pressure. So this means the evap is 50 degrees at idle. Broad rule of thumb is that discharge air is ten degrees warmer than the evaporator, so 60 degree vent air at idle. A better condenser will lower the high side pressure - not a bad thing at all - but without a change in low side pressure you won't see any better performance at idle.

- JimY
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