need help with ac charging

[Old smart]

Originally Posted by a2jack

Jeepster accepted and done.

The leaks, As posted on CsC, were micro seal and line failures attributed to long line runs to the rear engine. But even after seal and line replacements they would pup up again and again. It was obviously a design failure but MB was unable to cure it. Next they reprogrammed ECU to have the air con come on at lower temps with the defrosters in the winter, the theory being lack of lube.
That didn't work either.

It seems to occur each spring with warm air coming out of the AC, from loss of R-134 over the winter.

Go to CsC and read all the threads it's really interesting.

Regards A2Jack.

Yeah, I asked the "leak" question, and the answer is understandable. But now I query (and assuming that the word over time got back to M-B), has there been a substantive change made to the 451? Is this now only a 450 problem? Has a 451 had this problem?

[a2jack]

Oldsmart. The Canadians got their 451s just a couple months before us, so we are all waiting for that first, all winter long use cycle. Spring will tell. As usual, Smart is saying nothing.

As for why the auto mfgs don't use Duracool, 1. it's based on propane instead of CFC's. 2. There was a deal struck by Dupont when they forced R-12 off the market and EPA adapted R-134 (only made by Dupont). Yet Duracool is accepted by DOT and used in commercial refrigeration throughout the world.

I don't know the full story on the Dupont thing, but now I'm interested in what took place there. Anyone know the story?

A2Jack.

[a2jack]

Double post.

.

[sunnyokanagan]

The main cause of a/c leaking in the 450 in Canada (all diesels by the way) was failure of the o-ring seals due to the fact that the compressor is mounted on the vibrating engine and the hoses are all rigid lines running from there to the condenser at the front of the car 7 feet away.

The engine vibrates and the hose mountings do not, so the only possible point of flexion between the two is at the o-ring compression fittings on the compressor. This makes for inevitable failure - year after year - and each replacement of the same rigid hose and fittings will predictably leak in just the same way.

MB/smart has arrived at what we told them years ago would be the only lasting repair: they are supplying replacement linesets of flexible tubing.

We hope to hear in the next 3-6 weeks whether all 450 smarts will get free repairs to this failed design, or whether they think they want to charge those of us who are out of warranty. One CDN smartie was quoted $2,000 for the repair, but that was a few weeks back - we still haven't heard the official MB/smart position on this yet....

I don't know how, or whether, this same issue applies to the 451.