SMC Valve sticking when hot - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Irishpilot · 01-05-2010, 10:22 PM

Hey all, I searched the forum and found one post similar, but my rear valves get partially stuck after the exhaust warms up. So, after driving around town for a while, or on a road trip, if I try either inflate or deflate the rear, the down valve will partially stick open letting that side slowly settle. If I hit the up button a few times it will correct. What's weird is it only does on occasion, but never when the exhaust is cold.

The valves are mounted to the inside of the c-frame right by the rear bags. These valves are near the mufflers, which are towards the center of the bed.

Any ideas??? Thanks!

**N2TRUX** · 01-06-2010, 11:41 AM

Could it be heat transfer from your exhaust? I had a weld pull loose on my catalytic once. It caused the exhaust to be directed down the inner side of the frame. It generated enough heat to take a line out.

Could you be getting enough heat from your exhaust to cause the valve to stick?

Irishpilot · 01-06-2010, 06:42 PM

I was thinking it could be heat transfer, but I'm not sure if these valves would partially stick when overheated. I was wondering if anyone else had this same problem.

smashingchuck · 01-06-2010, 07:45 PM

I think you'll find the problem soon enought if you take them off the truck and blow the valves apart on a bench and clean them up.

Irishpilot · 01-06-2010, 08:31 PM

smashingchuck,

I was thinking the same thing as half of my valves are older. I originally had a 4 valve setup, and upgraded to an 8 valve (which I would recommend to anyone who actually wants to corner these old trucks). I'll give that a shot on my next rotation to the States.

Rollie396 · 01-06-2010, 10:35 PM

Irishpilot,how far from the exhaust is the valve?

Irishpilot · 01-06-2010, 11:46 PM

I'd say 12-18 inches. I mounted the valves on the inside of the frame to hide them from prying eyes and to help protect against road grime, water, etc.

01-05-2010, 10:22 PM	#1
Irishpilot Registered User Join Date: Jul 2006 Location: Kunsan AB, South Korea Posts: 187	SMC Valve sticking when hot Hey all, I searched the forum and found one post similar, but my rear valves get partially stuck after the exhaust warms up. So, after driving around town for a while, or on a road trip, if I try either inflate or deflate the rear, the down valve will partially stick open letting that side slowly settle. If I hit the up button a few times it will correct. What's weird is it only does on occasion, but never when the exhaust is cold. The valves are mounted to the inside of the c-frame right by the rear bags. These valves are near the mufflers, which are towards the center of the bed. Any ideas??? Thanks! __________________ 1971 C-10, 406ci, restoration begun! 406ci sb; zero decked, bored .030, edelbrock aluminum e-tec heads, edelbrock performer RPM intake, comp 268 cam, comp 1.6 pro-magnum roller rockers, MSD street fire HEI, MSD 8.5mm wires, Holley Street demon 770, Hedman LT headers. 10.6:1 compression, Air Ride Tech bags on all 4-corners.

01-06-2010, 11:41 AM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,023	Re: SMC Valve sticking when hot Could it be heat transfer from your exhaust? I had a weld pull loose on my catalytic once. It caused the exhaust to be directed down the inner side of the frame. It generated enough heat to take a line out. Could you be getting enough heat from your exhaust to cause the valve to stick? __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

01-06-2010, 06:42 PM	#3
Irishpilot Registered User Join Date: Jul 2006 Location: Kunsan AB, South Korea Posts: 187	Re: SMC Valve sticking when hot I was thinking it could be heat transfer, but I'm not sure if these valves would partially stick when overheated. I was wondering if anyone else had this same problem. __________________ 1971 C-10, 406ci, restoration begun! 406ci sb; zero decked, bored .030, edelbrock aluminum e-tec heads, edelbrock performer RPM intake, comp 268 cam, comp 1.6 pro-magnum roller rockers, MSD street fire HEI, MSD 8.5mm wires, Holley Street demon 770, Hedman LT headers. 10.6:1 compression, Air Ride Tech bags on all 4-corners.

01-06-2010, 07:45 PM	#4
smashingchuck It'd be alot cooler if you did Join Date: May 2003 Location: Three Rivers, MI Posts: 2,345	Re: SMC Valve sticking when hot I think you'll find the problem soon enought if you take them off the truck and blow the valves apart on a bench and clean them up. __________________ 78 Build Thread 4Runner Build

01-06-2010, 08:31 PM	#5
Irishpilot Registered User Join Date: Jul 2006 Location: Kunsan AB, South Korea Posts: 187	Re: SMC Valve sticking when hot smashingchuck, I was thinking the same thing as half of my valves are older. I originally had a 4 valve setup, and upgraded to an 8 valve (which I would recommend to anyone who actually wants to corner these old trucks). I'll give that a shot on my next rotation to the States. __________________ 1971 C-10, 406ci, restoration begun! 406ci sb; zero decked, bored .030, edelbrock aluminum e-tec heads, edelbrock performer RPM intake, comp 268 cam, comp 1.6 pro-magnum roller rockers, MSD street fire HEI, MSD 8.5mm wires, Holley Street demon 770, Hedman LT headers. 10.6:1 compression, Air Ride Tech bags on all 4-corners.

01-06-2010, 10:35 PM	#6
Rollie396 someday it will be done! Join Date: Sep 2004 Location: Lloydminster,AB. Canada Posts: 1,620	Re: SMC Valve sticking when hot Irishpilot,how far from the exhaust is the valve? __________________ '72 C-10 Proud owner of a million new and used pieces that used to be and will once again be(god willing) a testament to the term "they don't build em like that anymore. '80 LWB 2wd beater '67 GMC long fleet (cab donor) '66 long step (parked till it's turn comes around) '65 short step (parts truck that will donate it's bed and possibly frame to the '66) '06 Grand Prix wife's car (she hardly lets me touch it) my pics

01-06-2010, 11:46 PM	#7
Irishpilot Registered User Join Date: Jul 2006 Location: Kunsan AB, South Korea Posts: 187	Re: SMC Valve sticking when hot I'd say 12-18 inches. I mounted the valves on the inside of the frame to hide them from prying eyes and to help protect against road grime, water, etc.



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