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-   -   Leaking AC Schrader valve. Is Dealer Crazy? (http://www.peachparts.com/shopforum/tech-help/188123-leaking-ac-schrader-valve-dealer-crazy.html)

pberku 05-13-2007 09:17 AM

Leaking AC Schrader valve. Is Dealer Crazy?
 
The AC Schrader valve on the high pressure side is leaking. Dealer tells me that this valve is not replaceable, but that it part of the AC hose, and that I will need to buy a new hose at a cost of over $500.00. Is this for real? The only thing that prevents the refrigerant from escaping totally is the little plastic dust cap that screws on top. Obviously this plastic cap is not very effective considering the high pressure.

Can I stop the schrader valve from leaking somehow? Any ideas?

Jackd 05-13-2007 09:21 AM

Dearler is not crazy, Mercedes parts prices are sometimes crazy.
Before spending $500. for a leaky shreader valve, I'd remove the schrader valve core and install a new one on top of the old one, using an appropriate adaptor.
Might cost you $10. in parts and a A/C refill

pberku 05-13-2007 11:12 AM

The problem is that the core of the Schrader valve on this car is not removable. and the Schrader valve assembly itself, although looks like its only screwed into the high pressure AC hose, apparently is also not removable.

brewtoo 05-13-2007 11:25 AM

Quote:

Originally Posted by Jackd (Post 1505133)
Dearler is not crazy, Mercedes parts prices are sometimes crazy.
Before spending $500. for a leaky shreader valve, I'd remove the schrader valve core and install a new one on top of the old one, using an appropriate adaptor.
Might cost you $10. in parts and a A/C refill

That sounds like a wise way to handle this problem.

Arthur Dalton 05-13-2007 11:58 AM

Sometimes iti s just dirt..push it in and release it quickly..retest..

Jackd 05-13-2007 02:04 PM

1 Attachment(s)
I'm a bit surprised the valve core can not be removed....but everything is possible.
Second solution:
Remove the hose.
Have the original valve soldered shut.
Cut the original hose and have a new valve soldered on. Any commercial A/C place can do that. Re-install the hose.
refill system.
I'd try a couple of inventive ways of saving that hose.
I know, I'm cheap:)

This is the type of valve you need,

ozawa 05-13-2007 05:14 PM

not unheard of...some Chevy Suburbans are the same way. schrader valve goes bad, have to replace the entire hose assembly. just did one about a month ago...

as more and more OE suppliers get consolidated, i wouldn't be surprised if this setup exists on other vehicles as well.

pberku 05-13-2007 05:48 PM

Quote:

Originally Posted by Arthur Dalton (Post 1505194)
Sometimes iti s just dirt..push it in and release it quickly..retest..

Well. I took Arthur's suggestion, pushed the valve in, and released it. IT STOPPED Leaking. I don't think however that I am out of the woods yet. I also need to change my defective, high pressure switch, and for that of course they would need to evacuate and recharge the system. At that point they will be connecting their AC gauge hoses, so the leaking valve may manifest itself again.

Can the system be legitimately recharges without using a high pressure gauge? Also, my rebuilt compressor came with a Schrader valve built-in. Not sure what that its for, but could the high pressure gauge be connected there instead?

One last thing. Can I get away with only one working cooling fan. The second fan is defective.

Arthur Dalton 05-13-2007 05:51 PM

<<I also need to change my defective, high pressure switch, and for that of course they would need to evacuate and recharge the system. >>


..and just what is wromg w/sw ???

pberku 05-13-2007 05:55 PM

The high pressure switch does not activate the fans. yet the system is full of refrigerant. Until Its fixed, I rigged up a bypass switch that allows me to run the fans (actually only one working fan) continuously, Basically I am shorting the output of the high pressure switch using an external toggle switch

Arthur Dalton 05-13-2007 05:59 PM

You are positive about the refrig charge???..you look at the eye-sight?? you have gauge readings ?? Do you have high ambient temps?

Go read this to save my two little typing fingers this is a recent post..
get back to me

http://www.peachparts.com/shopforum/tech-help/188057-300e-aux-fan-fuses-strip-fuse.html

pberku 05-13-2007 06:14 PM

The charge is not full, I do have bubbles, but its cooling pretty well.

1) I am assuming that by the fact that I can get the fan (s) to work by jumping the output of the high pressure switch, that the the rest of the related ancillary circuits, fuses, relays ect.. are all ok.

2) Turning the AC on, and If I don't switch the fans on mannualy, and touch the AC metal pipes going to the condensor, they become way too hot to hold.

3) I don't really know what my high preasure readings are, ans the last thing that I want to do is reconect anything to the High preasure Schrader valve.

What do you think I should do? Still think that the switch could be OK? Do those switches break often?

Arthur Dalton 05-13-2007 06:42 PM

[QUOTE=pberku;1505443]The charge is not full, I do have bubbles, but its cooling pretty well.

1) I am assuming that by the fact that I can get the fan (s) to work by jumping the output of the high pressure switch, that the the rest of the related ancillary circuits, fuses, relays ect.. are all ok.
That is correct . That is the circuit intergrity test, minus the pressure sw.
[ which may or may not be bad ...VERY FEW are bad]

2) Turning the AC on, and If I don't switch the fans on mannualy, and touch the AC metal pipes going to the condensor, they become way too hot to hold.
Normal, but that is an indication of good head pressure ..the tubes you are interested in are the end tubes and heat across the full condenser .

3) I don't really know what my high preasure readings are, ans the last thing that I want to do is reconect anything to the High preasure Schrader valve.

What do you think I should do? Still think that the switch could be OK? Do those switches break often?
See above.

If you have a lot of eyesight bubbles , you are not fully charged.

You did not mention an important factor ...ambient temps

jbaj007 05-13-2007 07:15 PM

I find it hard to believe that the EPA , with their micro-management of every little aspect of MVAC, would allow a fitting to be used that did not have a renewable/replacable valve core. I know you all are saying it's so, but I just can't believe it. That's nuts.

They mandate systems cannot be topped off without leak checking and leak repair, how can they allow a fitting w/o a fixable seal?

Someone with a 1995 E class, go get your bicycle stem cap, and see if your A/C fitting valve core unscrews a little. ;)

Arthur Dalton 05-13-2007 07:30 PM

<<Someone with a 1995 E class, go get your bicycle stem cap, and see if your A/C fitting valve core unscrews a little.
>>

Yeah, right ..

Did you ever see the design of the valve ports on a 134a system??
Ths is not bicycle inner tube stuff.......


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