All,

My 240 is going in for re-fit Wednesday. Are there any parts or seals to be replaced under the dash? My mechanic says no, and that it is an easy job with a simple(under $100) kit.

Can any of you recomend a book on automotive AC ?

What would you say the life of the AC compressor could be? In miles or years. Mine is working, the car has 120k on her. The car is used in Michigan where the AC will be unused for five months (bad for it) and run full blast the rest of the time (Black car).

Thanx guys, I am a bit nervous about this converson thing as I spent a FORTUNE keeping up the system on my old Benz.

Mak

No under dash seals should be necessary.

All conversions have to be done carefully. That compressor (Diesel Kiki, probably) lasts pretty well with R134a.

Make sure the orifice tube is changed. Extremely important (and frequent shortcut to leave it out).

Also, one trick for conversion on 91-92 240 series cars, is to jump the electric fan switch at the high side pipe halfway back on the right side frame rail at the bottom of the engine compartment, accessed from the right side of the car under the hood. This is a little "J" shaped pipe with a wiring harness attached to the pressure switch on it. All that has to be done is the wiring harness (two wires) removed and a wire passed between both terminals. Then tape the whole thing up and leave it alone. that will cause the fan to function WHENEVER the air conditioning switch on the dash is on. It makes a very positive impact on the system with R134a. otherwise the fan only runs with pressure of a certain rate.

Also lowering the cycling pressure to the 20 pounds range helps a little bit.
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chris herbst, near chicago

chris,

Thanks for the advice. If Ali does not alter the fan wiring I will change it myself. Guess I will need to trust him on the orifice tube because I dont know what one looks like. I am going to buy a book today and put my nose in it so I know what is going on.

My other car is a Mercedes. A 300SD with 300K on her. Sharp car, but the R12 has escaped over the winter. This system has been a nightmare for both myself and the last owner. A combination of age and shoddy workmanship. The last shop that had it told me not to bring it back. " We will no longer service R12 systems and we will not take your dash apart". A shame, he was the best wrench I had found.

The car has a Harrison R4 compressor and a thermal expantion valve (H Block)under the dash. I dont need to drive the car anymore but I cant sell it the way it is. So it looks like a Shade Tree project. Ali has quoted the job at $900-$1000. I cant do that, the car has almost no value. I need to have fun spending that kind of money. If I spend $400 in parts and $400 on tools I'm ahead.

Thanks again

Mak