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Replace GM High Side Service Port with Schrader?
Posted: Sun Jun 26, 2016 1:52 pm
by jamyers
2000 Chevy Silverado 5.3 V8, the high side valve leaks. I thought it was a standard schrader valve in there, but noooooo, GM had to come up with a new and improved (not really) valve.
I can easily get the GM OEM-style valve, but is there a good replacement that uses a standard Schrader valve? From reading online, the OEM ones are problematic enough that people don't even want to hook gauges to them.
Re: Replace GM High Side Service Port with Schrader?
Posted: Mon Jun 27, 2016 6:12 am
by Cusser
Can you seal the leak with a new, high-quality cap? If that takes care of it, that's what I'd do first.
Re: Replace GM High Side Service Port with Schrader?
Posted: Mon Jun 27, 2016 1:47 pm
by jamyers
Nope, the original one is shot. No cap is going to seal this one...
Looks like the Dorman Products 800-955 is a Schrader Valve replacement for AC Delco 15-5438 / GM 52458184, I'm going to get my hands on one this afternoon and see, then post results here.
(With all the EPA freak-out over venting refrigerants, you'd think they'd be all over GM about their OEM valve, which apparently has a long history of leaking refrigerants)
Re: Replace GM High Side Service Port with Schrader?
Posted: Mon Jun 27, 2016 2:30 pm
by 72gmc4x4
It upsets me too to see them fail but if it's the original valve, that thing is 16years old. I'd say that's a pretty long service life. I think the reason the valve failed is because the gauges damaged it.
Re: Replace GM High Side Service Port with Schrader?
Posted: Mon Jun 27, 2016 5:40 pm
by jamyers
72gmc4x4 wrote:It upsets me too to see them fail but if it's the original valve, that thing is 16years old. I'd say that's a pretty long service life. I think the reason the valve failed is because the gauges damaged it.
Yeah, I hear you - 16 years isn't bad...but then the schrader valves in my '71 Buick are all original...and gauges don't kill them.
I'm still adding this valve to my "List of Grievances" that I'm going to take with me if I ever get up to Detroit (which will be NEVER), lol.
I love this forum, best A/C info anywhere!
Re: Replace GM High Side Service Port with Schrader?
Posted: Thu Jun 30, 2016 10:18 am
by jamyers
The Dorman 800-955 is a direct replacement, with an actual schrader valve inside.
http://www.dormanproducts.com/itemdetai ... me=800-955
Re: Replace GM High Side Service Port with Schrader?
Posted: Thu Jun 30, 2016 12:42 pm
by GM Tech
A good cap with rubber washer inside will seal it--they all leak, this is how I test my sniffer- take a cap off to test it....I was like you - did not believe it until I tried it and talked to the lines and hoses engineers at GM- they designed the caps to seal as the primary seal- they tell me the valve is just there to seal off long enough to put a cap on.
Re: Replace GM High Side Service Port with Schrader?
Posted: Sat Jul 02, 2016 6:42 pm
by jamyers
Valves that don't seal by design... Yet another one of GM's many 'improvements', harrumph.
Re: Replace GM High Side Service Port with Schrader?
Posted: Sat Jul 02, 2016 8:08 pm
by wptski
If these valves are designed to leak then why didn't my 1990 Buick leak for twenty years?
Re: Replace GM High Side Service Port with Schrader?
Posted: Sun Jul 03, 2016 3:52 am
by GM Tech
The valves are not designed to leak, the caps are designed to be the primary seal. If you are running without caps, then that is your choice.
Don't believe it? Do what I do, use your sniffer with cap off-- it goes nuts, put cap on (with good rubber seal inside) snug it down - wait 5 minutes- re-sniff with sniffer, and sniffer is happy....I never leak check with hoses attached to vehicle, the cap and port could be the culprit, and you'll never find it with the hoses attached....been there done that after 30 yrs.....