The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 04-19-2004, 02:26 PM   #1
PHOENIX
Registered User
 
Join Date: Oct 2002
Location: Phoenix, Arizona
Posts: 4,703
Exhaust Check Valve (used with somg).

I have been trying to get some things cleaned up and working better on the truck. I decided to remove the smog pump system until I get the new exhaust system on. I had some leaks I wanted to get rid of. Well I got the pump assembly off and the rubber hoses that bring air to the check valves. I started the truck and noticed that some exhaust was making it through the check valve. A very small amount, but you could hear the exhaust leak at idle. I know with the air pump running this probably makes no difference. Anyway if I rev'ed the engine it sounded like it was a good leak. Is this normal for these valves or should I buy new ones when I install the new exhaust system? I ended up pulling the injection tubes and plugging the holes for now.

thanks.
__________________
* AVOID: LOPER'S PERMORANCE / LOPERSPEED.COM OF PHOENIX, AZ & COTTMAN TRANSMISSION *
PHOENIX is offline   Reply With Quote
Old 04-19-2004, 02:48 PM   #2
MylilBowTie
Right turn Clyde
 
MylilBowTie's Avatar
 
Join Date: Nov 2002
Location: Cincinnati, Ohio
Posts: 2,911
Im pretty sure thats normal. Its what mine did when I took the pump and hoses off. Ended up getting the tubes out and had them welded.
__________________
1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73
1992 Camaro RS 305 TBI
MylilBowTie is offline   Reply With Quote
Old 04-19-2004, 10:15 PM   #3
plumbcut
california fill
 
Join Date: Apr 2004
Location: Sunny So-Cal
Posts: 694
Im pretty sure that they should NOT leak. I would bet money on it. That defeats the whole purpose of a check valve, if they are leaking... Replace em! Or.... just leave the whole system off and plug the manifold holes like you did...

pc
plumbcut is offline   Reply With Quote
Old 04-20-2004, 11:56 PM   #4
Chemuk
Registered User
 
Join Date: Feb 2004
Location: Wichita Falls, Texas
Posts: 3
The check valves are not supposed to leak. In fact my right check valve gave way and burnt up the Air valve, melted it like butter. Smoke was rolling out of the truck. If I had not shut it down when I did it probably would have started on fire. I went and bought a new check valve for $15.00 bucks and stuck it in, no exhaust leak and no more smoke. It was easier for me to just buy the new valve then try to weld the tube closed. The check valve stops the exhaust gasses from reaching the A.I.R pump so it doesn't melt.
Chemuk is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:06 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com