A/C overcharged? high engine load, increased running temps, stalled...thx for input - Page 8 - PeachParts Mercedes-Benz Forum

1980sd · #**106** 06-24-2011, 12:42 PM

Sounds like it could be one of your check valves. I had a similar problem and traced it back to the big check valve on the main brake booster line. Maybe isolate everything but the shut-off valve and see if it still does it.

Mine was completely wonky

Wouldn't shut off unless the hi or lo cool buttons were pressed in sequence

I just isolated each system one by one and finally got everything working.

I actually got my servo working great but it binds when it gets hot.

Cools off and it works, gets hot and the servo motor binds causing my amp to get hot and it stops working. Cools off and it's fine again...

I can loosen the screws that hold the "gear plate" (Under the top cover) with it hot and the motor starts working. My body is cracked where the screws go so maybe that has the housing distorted

I just read your whole saga and it sounds just like mine!

Pisser to get the servo part working and have the compressor/refrigerant part crap out

sshanky · #**107** 06-24-2011, 01:19 PM

It sounds like you need a new aluminum body instead of the plastic one. I have an extra.

1980sd · #**108** 06-24-2011, 01:33 PM

PM me if you want to sell it.

sshanky · #**109** 06-28-2011, 12:36 AM

OK, I finally got the gauges on. I'm pissed off that I didn't get to this BEFORE bringing it to the shop last week. He told me he took out some refrigerant, and now I will never get to know what it was like before.

I guess things were pretty decent:

Doors slightly cracked, windows closed, engine idling about 1500 RPM

Big fan blowing directly into front of radiator, right over aux. fan (Aux fan didn't have to come on at all)

Blue gauge: 20 psi (went up to 25 or so with slightly faster idle)
Red gauge: 250 psi
Ambient temp.: 103 F
Cold air temp: 48.2 F on low speed fan (I guess this was pretty good, right?)

Photos

Gauges:

Fan setup:

Thermometer probe in air vent:

Inside temperature:

Outside temperature:

Check out the Benzes outside:

leathermang · #**110** 06-29-2011, 12:02 AM

WINDOWS OPEN !!!!!
Otherwise looks great.... Good job...
A really good shot at good ac for a long time...

LOL, 103 F ambient.... and people wonder why some of us are more into AC than others....

sshanky · #**111** 06-29-2011, 12:06 AM

Actually the doors were open partially, like 1/4 of the way open. So, you think I'm good now? I am sure it was overcharged before I brought it in. I can't believe he wanted to charge me for the visit. I do notice it's not *quite* as cold as it was before -- wonder if I should add a tad of freon.

leathermang · #**112** 06-29-2011, 12:09 AM

I suggest you hold what you have... those are good numbers for that ambient...
Not having the windows down may be why your aux fans never came on.. you need to have it working all the time you are charging so it gets spread around the system...
Will work fine several oz lower than capacity... but one oz over will kill it quickly from overwork...