The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

Speedster 229 · 09-19-2003, 10:20 AM

On my 70 1/2 ton with power brakes I can't get the line lock to hold. I have all new drum brakes from the master cylinder on. The truck stops fine but when I pump the brakes and then set the line lock it won't hold the truck back for a burn out. I'm running a SBC approx. 400 HP 3:73 posi 7000R4 2800 stall and 315/60R15 Drag Radials. Is there a way to adjust the perportioning valve ??
Any help would be appreciated.

09-19-2003, 10:20 AM	#1
Speedster 229 Registered User Join Date: Oct 2002 Location: Spokane Wa. Posts: 36	Perportioning Valve adjustment On my 70 1/2 ton with power brakes I can't get the line lock to hold. I have all new drum brakes from the master cylinder on. The truck stops fine but when I pump the brakes and then set the line lock it won't hold the truck back for a burn out. I'm running a SBC approx. 400 HP 3:73 posi 7000R4 2800 stall and 315/60R15 Drag Radials. Is there a way to adjust the perportioning valve ?? Any help would be appreciated. __________________ 1970 1/2 ton LWB 350 / 700R Rebuilt top to bottom. Not custom, but really sanitary!!!!!!!!