1991 300D A/C pipe (hose) identification help - PeachParts Mercedes-Benz Forum

sfsegui · #1 05-09-2016, 05:32 PM

Developed a slow leak in my air conditioning towards the end of last summer in my 91 300D. Did some investigation and found where the leak was coming from. It is the pipe that goes through the firewall on the driver's side to the expansion valve (I believe). Is this the suction pipe? If someone can give me clarification on the name of the pipe or even better, a part number that would be great. You can see the refridgerant leaking from the pipe directly behind the large nut in the pic I posted. There is a small cut in the pipe. The gasket surrounding the pipe somehow worked its way behind the firewall letting the pipe rest against the firewall and over time with my poor motor mounts (recently changed) I guess the vibration finally caused the pipe to crack allowing the leak (and I bet contributed to the premature failure of my engine mount on that side). Thanks. -Scott

vstech · #2 05-09-2016, 07:21 PM

Yes, that is the suction line. I think you have to get a compressor manifold to change it...

vstech · #3 05-09-2016, 07:24 PM

I got stung by a wasp opening my hood to look for you... It hurts...

sfsegui · #4 05-09-2016, 08:34 PM

Thanks for the confirmation and sorry about the sting. No good deed goes unpunished, right?. Actually, I haven't decided if I will be changing it or not, meaning I may just get the part and hopefully my indie will replace it for me. When you said I would need a compressor manifold to change it, it isn't just a matter of unscrewing the big nut and removing the suction pipe from the switchover valve (after the system has been drained)?

vstech · #5 05-10-2016, 04:12 AM

If the pipe in the firewall is damaged, yeah, just replace that. Duh on me... with the amount of residue... I don't think much refrigerant will need to be drained!