Possible AC Shrader Valve Failure

Pneumo

Member
Hey all!

Hoping to get an second opinion on my diagnosis before taking it anywhere.

Recently while driving, my AC effectiveness greatly reduced. The van has been driven infrequently over the past y months or so here in Montana. I do prescribe to the small incremental temp chance outlined in the manual and have never had issues overly past 4+ years of ownership. Van is an 08 Dodge 2500 sitting at 186k and does not have a rear AC system for what its worth.

I inspected the electrical system, compressor(not sure how best to test the clutch), and lines for any obvious issues. I admit that refrigerant is something I am not at all familiar and I understand that I might not necessarily be able to see a freon leak, but looking over the system seemed like a decent course of action.

Just today I pulled off the dust covers to the shrader valves to take a peak, the van has not been run in a week and was off at the time. I did not touch the valves but did see a small amount of yellow fluid on one valve which was bubbling slightly. I assume this could be the cause of a leak and the decrease in ac performance.

Does this bubbling sound to anyone else like the possible site of failure? I don't plan to fix the issue at home, but if I can diagnose the issue and have a local shop recover, replace the shrader valves, and refill the system to spec, I would prefer that.

If anyone has any diagnostic advice, I'd be happy to hear it! Otherwise I'll go with my diagnosis and see what that would run me locally. If they diagnose a failure elsewhere in the system, is there any concern with having them recover the freon, replacing components myself, and having them recharge the system? I generally prefer to do my own work for the experience and as a hobby, but I'm not interested in doing so if I'll advised for environmental or safety reasons.

Thanks in advance!
 

lindenengineering

Well-known member
Leakage from the charge couplings are not an unusual occurrence or observation.
The valves are modularized and observed them attached to the expansion valve coupling behind the air cleaner box.
Supplied by MB under part number 0028305484 (Hi side )
& 0028305584 lo side they take about 15 minutes to remove and install.
Always oil the threads with Pag oil before installation.
I can't see why a shop wouldn't evacuate the system allow you to install these parts then return for re-charge.
That stated it's such a simple task to swap out the valves, i bet if you present the two units they will probably install them for you FOC or at a minimal charge checking for leaks with profesional leak testing tools to a 2 parts per million settings.
All the best
Dennis
 

Pneumo

Member
I can't see why a shop wouldn't evacuate the system allow you to install these parts then return for re-charge.
That stated it's such a simple task to swap out the valves, i bet if you present the two units they will probably install them for you FOC
Thanks for all of the insight and part numbers Dennis! Hope your shop is doing well these days.

I would fully trust a shop to replace the valves, if that is indeed the failure point. I mostly asked about that scenario in case there is something else that failed in the system, ie lines, compressor, ect.

I may just order those valves and bring the van down to the shop for diagnosis and go from there.
 

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