how difficult?

[texasplaya]

i got my a/c checked and they said my high side shreeder vavle is leaking how hard is it to change and can it be done by me if all the freon is leaked out trying to save me some money

[brcidd]

They have not found the leak-- they are guessing- because they do not know that as designed- the little plastic cap (with the rubber insert in it) is the PRIMARY seal, the schrader valve is there just to allow time to put the cap on. Believe it or not- but I know this for a fact-the plastic cap seal it off when in place properly-- so do you use the caps? does your cap have the rubber insert gasket in it? Lots of cars I see are missing the caps- mechanics drop and don't retrieve them.

You failed to mention the model year of your car-- but the number one leak location is the compressor shaft seal followed by the compressor belly o-rings- both of which can be replaced....If you replace that schrader valve- then recharge- you will be back soon asking your "ace" mechanic where the real leak is...

is the front of compressor pulley area greasy- is there an oil sling path from pulley area?

[Airjer_]

Originally Posted by brcidd

the little plastic cap (with the rubber insert in it) is the PRIMARY seal, the schrader valve is there just to allow time to put the cap on.

Interesting? That little plastic cap is supposed to hold back a couple hundred PSI on the high side?

[brcidd]

believe it or not- been that way for several years- I did studies on them as well- because I did not believe it at first.....why else would there be a rubber seal if the shrader was the primary seal??

[Airjer_]

Oh, i don't know maybe to keep out water, dirt, debris, misc leaking fluids, misc. engine cleaners, etc?

They put rubber seals in valve caps for your tires as well. Is that because the cap is the primary seal? They have seals in the caps for the fuel test ports on a lot of vehicles, are those caps the primary seals also?

[richtazz]

I'm with Airjer here. The cap is just to keep dirt/debris out. The schrader valve is the pressure seal point and no freon should escape unless it is pushed in.

[brcidd]

Well I happen to work with the lines and connection designers for a/c so believe what you want......

Have them leak check with their sniffer with the cap on-- then tell you that is where the leak is......see if they can keep a straight face- and see if your a/c works all summer....

[ctwright]

Originally Posted by brcidd

the schrader valve is there just to allow time to put the cap on. Believe it or not- but I know this for a fact-the plastic cap seal it off when in place properly

I'm sorry but how could you possibly know this, it is impossible to fill it up with no valve because as soon as you went to put the cap on you would have a problem, and if you filled it up with the valve, then put the cap on, there is know way to take the valve out, so how do you know for a fact that the cap will alone hold the pressure?

[troy1]

I've always considered the cap the secondary seal. keeps the junk out and small leaks contained if for some reason the schrader valve has not seal properly.

[brcidd]

The point is, that the fact that the schrader bubbles a little-is that the cap will seal it- replacing the shrader will not fix the system leak-- he has a leak elsewhere.

I know that the caps seal because I have built test systems where I evac and fill from other ports I made for the system- and I have been able to put caps on filler ports and seal them without a shrader valve under them...