A/C problems are BAD - PeachParts Mercedes-Benz Forum

Biglex · #1 06-08-2007, 01:31 AM

dealer retro fitted my 92 300D to the 134, recharged it and all that good stuff, said they saw no leaks, drove off, it was fine. Next day, NO A/C. Took it back, $1105 was the quote I got. Yeah, I told them I would trade it for another one (a used one) before I paid that for AC. Damn Nazis.

JimFreeh · #2 06-08-2007, 06:27 AM

Quote:

Originally Posted by Biglex

dealer retro fitted my 92 300D to the 134, recharged it and all that good stuff, said they saw no leaks, drove off, it was fine. Next day, NO A/C. Took it back, $1105 was the quote I got. Yeah, I told them I would trade it for another one (a used one) before I paid that for AC. Damn Nazis.

Well, first, it could just be coincidental. This is a 15 year old car we're talking about here.

Also, when a description only includes the cost, it's hard to speculate on what the problem could be, but I'll try....

At that price, it's too low for the evaporator to be the problem, so that leaves the compressor, the condenser, the hoses and the electric controls.

First, determine if the system has pressure. If not, then its mechanical, if it does, and at rest has between 60 to 100PSIG, then look for an electrical problem. Since it did work initially, I'd guess the freon is gone. Another tip is check what was perturbed when the last work was done. Chances are, the conversion was merely a removal of any residual R-12, a changeout of the hi and low pressure connectors, a system vacuum, then a charge of R134. It's a long shot, but maybe the connectors/adapters are not properly sealed. Low side is blue and forward of the brake booster, high side is red and beside the condeser in front of the radiator.

There is a step by step process in the manual/CD to find the problem. When working on A/C, you need to have A/C specific tools such as a manifold gage set, a freon sniffer, and the normal stuff like a voltmeter.

Jim

Dee8go · #3 06-08-2007, 08:50 AM

Shouldn't the dealer have checked the system for leaks prior to doing the conversion? It seems like they should do something for you.

dannym · #4 06-08-2007, 10:06 AM

That's BS. They should have some kind of guarantee beyond 1 day!

Danny

winmutt · #5 06-08-2007, 10:09 AM

I would contact MBUSA.

ILUVMILS · #6 06-08-2007, 12:22 PM

Quote:

Originally Posted by Dee8go

Shouldn't the dealer have checked the system for leaks prior to doing the conversion? It seems like they should do something for you.

There are several different schools of thought when it comes to A/C diagnosis. Some think the system should be leak-tested first. Others think it's best to convert the system and verify the refrigeration circuit ( compressor, expansion valve, etc ) is in good working order before spending time checking for leaks. I've found that it almost always works out better for the client to convert the system, verify correct function, and then give it a quick leak test. If no leaks are found, we'll add some UV dye to the system and re-check it at the clients' convenience.

Biglex · #7 06-11-2007, 12:08 AM

for the most part, I am pissed off how this was handled. It is no big surprise when a 15 year old AC system goes out, it is the fact I paid $225 to have it leak tested, retrofitted and recharged, then the next day it was out again. They even added dye. One of the mechanics even said when I came back "it is probably leakin like a siv". Well dumbass, you should know, you worked on it, why did you tell me you found no leaks???

Just thinking about this again has my blood boiling. I cant wait to talk to them tomorrow.

pmckechnie · #8 06-11-2007, 07:50 AM

I have seen this happen many times before. I work on an old car, no freon at the time, charge it up, check for leaks and find none. Later when the system is run for a while, the pressures go up from siting in traffic, something lets go and the freon comes out.
Now, a question for the AC experts, How do you find a leak without charging the system first? What do you do if you can't find a leak, but there was no freon in the car when it comes in? I recharge the system, add dye, check again, and hope for the best. $225 is not a bad price for that. I agree that it cost the customer and he has gained nothing except now the leak can be found.
I have a 92 300E coming back today that I charged up about a month ago. I couldn't find any leaks then. I learned that the car had just had a head gasket put on so I figured the freon was lost then and was not recharged. I did put dye in it so I should be able to find the leak this time.

vstech · #9 06-11-2007, 09:29 AM

on a flat system, you KNOW there is a leak unless like said above, major engine work was recently done. I always pressurize the system up to 100psi with dry nitrogen and wait 24 hours and test pressure, if it's not still around 100psi, ther is a leak. if it is less than 50 psi there is a BIG leak. evac. fill with UV dye and run the system. EXPLAIN this to the customer and wait for the customer to return so the leaking component can be identified.
it sounds like the dealer did what was asked, but failed to explain to you what was needed. a leak is not something that can be found on a car in a few hours, it sometimes takes WEEKS for enough freon to leak out to show up a stain. did you want to leave the car that long? did you want the techs to drive your car for the requisite days to get the leak to show up? relax. and chalk it up to busy techs.

Biglex · #10 06-12-2007, 01:22 AM

well i gotta admit, after reading the last 2 posts, I do feel a bit better about the whole situation. I am still not going to pay $1100 to get it fixed. I may buy the part and do it myself, or have an AC specialist do it. They tend to be a little cheaper than the dealers on labor at least.