Replacement for high side valve?

I suspect my leak is from the high side valve, system won't hold more than 15 pounds.

Any source for a replacement valve?

Are you talking about the high valve for your AC?If so the valve,s,both high and low sides are available at OReilly,s,Advance,Pep Boys and just about any auto parts store.Hope you have a pump and a reclamation machine.

The o-ring under the plastic cap on the HS valve will retain a lot more than 15psi. If it's there, I'd be looking elsewhere for additional leaks.

As Flasheroo implied, proper service of your AC requires more than a Wal-Mart kit with a hose, pretty gauge and a couple of cans of refrigerant (aka "death kit" or "black death kit" in the industry). The only things more likely to cause damage than moisture inside the AC are some of the "sealants" included in those kits.

If you want to understand how to service your B-body AC without permanent damage, have a read through this: http://www.buickforums.com/forums/showthread.php?t=26737

If your high-side port is leaking, your only two options are to replace the whole line assembly (did that, it's not that hard), or simply get a repair cap that clamps on overtop of the existing port and includes a new valve. It's called a service valve assembly I think.

sherlock9c1 wrote:

If your high-side port is leaking, your only two options are to replace the whole line assembly (did that, it's not that hard), or simply get a repair cap that clamps on overtop of the existing port and includes a new valve.  

Nope, they are replaceable. I replaced mine, anyway. You need a special 8-sided socket to unscrew the port from the welded socket on the line, after the system has been evacuated. Then, as described in the link above, the system must be vacuumed and recharged.

However, if the cap and o-ring are in place, that's not likely how the refrigerant is escaping anyway.

buickwagon wrote:

Nope, they are replaceable. I replaced mine, anyway. You need a special 8-sided socket to unscrew the port from the welded socket on the line, after the system has been evacuated. Then, as described in the link above, the system must be vacuumed and recharged.

However, if the cap and o-ring are in place, that's not likely how the refrigerant is escaping anyway.  

Do you have a picture of this?  The GM FSM says the only way to fix is to add a "service repair" port on top of the existing port, or replace the line.  I looked at it pretty closely and it did not appear to be removable.  The low side was a Shrader valve style port and was definitely replaceable.

Read your other thread BTW - nice work!

Actually there is a tool for the HS that allows you to remove and replace the leaking core and not lose any coolant.Cost 30 to 40 dollars and from what I have read works very well.There is also a tool for the low side that does the same thing.

Post up a link or a pic! Sounds like a cool tool.

Paying close attention. I don't have the money to pay someone to do this. 96 degrees today... was miserable.

It is a cool tool. Won't work on the B-body though -- our core is not replaceable unfortunately. Here is an example:

https://www.rockauto.com/catalog/moreinfo.php?pk=3920700&cc=1022184

Here's the fitting installed on the RMW:



The threads seen inside are for the cap -- not a replaceable Schrader valve core.

BTW: while the special socket is readily available in the US, it is not so available in Canada. Apparently there are export restrictions on the socket! Maybe one of your ICBMs or stealth fighters or something uses a similar style bolt head???

Anyway, I had to make my own:

What's a good quality replacement valve? There a brass one made? Not sure how brass and aluminum work together. I know brass is copper and tin, so aluminum and brass should be happy together, right?

So if the system won't take more than 15 pound (past that it just drops down, but not to zero) it could be the valve right? Anything else I think of would be complete void. Only a bad valve would leak past 15 pound imho. Am I wrong?

What year is the car? The valve that's in there is likely at least 17 years old, so I really don't think the quality was an issue. And I can't say as I've ever seen a brass one.

As I said before, I doubt the valve is the culprit, if it has the cap in place. A hole in the pipe is unlikely, as that would leak down to 0, but an o-ring joint or the compressor shaft seal could easily account for your symptoms -- the rubber having just enough elasticity left to seal things up at 15 psi. It's also possible your gauge is no good -- no offense intended, but did you check to see that it returns to 0 when completely depressurized?

buickwagon wrote:

What year is the car? The valve that's in there is likely at least 17 years old, so I really don't think the quality was an issue. And I can't say as I've ever seen a brass one.

As I said before, I doubt the valve is the culprit, if it has the cap in place. A hole in the pipe is unlikely, as that would leak down to 0, but an o-ring joint or the compressor shaft seal could easily account for your symptoms -- the rubber having just enough elasticity left to seal things up at 15 psi. It's also possible your gauge is no good -- no offense intended, but did you check to see that it returns to 0 when completely depressurized?

I filled two other cars that day, so the gauge is good.

When the ac runs, when the compressor runs I hear like a pressurized air sound when it cycles.

I guess I will have to put some uv dye in and find out.

Just didn't want to have to do that as I'd have to fully vacate the system to clean it all out when I find the leak that way.

You can inject UV die without evacuating the system and you can leave the UV die in there for ever afterwards. Many cars come with UV dye in the factory fill these days.

Fill your hose with UV dye and add some refrigerant to the system. That will flush the dye from the hose into the system.

A compact flourescent "black light" bulb in a worklight works very well for illuminating the dye. Incandescent "black light" bulbs are nowhere near as efficient. Some LED UV lights work ok, but many are the wrong wavelength or too weak.

buickwagon wrote:

You can inject UV die without evacuating the system and you can leave the UV die in there for ever afterwards. Many cars come with UV dye in the factory fill these days.

Fill your hose with UV dye and add some refrigerant to the system. That will flush the dye from the hose into the system.

A compact flourescent "black light" bulb in a worklight works very well for illuminating the dye. Incandescent "black light" bulbs are nowhere near as efficient. Some LED UV lights work ok, but many are the wrong wavelength or too weak.

I have a magnaflux blacklight for checking for block cracks. Funny enough we have some very rare minerals here found only in NJ that fluoresce
under black light, so I have a nice short and long wave light.

I'm guessing you have done this before, will the leak be very obvious?

It depends what's leaking, where it's leaking and how clean the environs are. A compressor shaft seal leak tends to spray stuff everywhere, as the shaft is spinning. An evaporator core leak might only be visible at the drip tube outlet under the car. Foam rubber insulation around a swaged fitting may absorb the dye and/or mask the source. And bright lighting can make it difficult to see the dye fluoresce. However, all that said, it's a very good way to pinpoint small leaks in the visible areas of the system. I have an electronic leak detector as well, and it requires a bit of skill and practice. Sometimes a sacrificial virgin. I find the two work best together -- the sniffer will guide me to the general area, the dye will pinpoint the exact location.

I like that idea, sniffer for a rough idea then check with light. Will check and see what I find...