Master Cylinder line issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BuckTruck16 · 10-10-2012, 06:55 PM

We have a '79 k10 with a 5.7L, with a disc/drum setup. We just replaced all the lines but are not sure what lines go to what. As in, the master cylinder has 2 ports. The one in the front is larger than the one in the back. Is the bigger port in the front for the front breaks or rear? And which one goes in which for the proportioning valve?

-Thanks

BuckTruck16 · 10-11-2012, 08:51 PM

Any luck?

Keith Seymore · 10-11-2012, 09:09 PM

The larger part of the reservoir, regardless of whether it is at the front or the rear of the master cylinder, goes to the front discs. This is because the disc brake pistons take more fluid to actuate than the rear wheel cylinders.

I believe that same brake line goes into the proportioning valve because it has a "hold off" feature which keeps the discs from applying until the slack has been taken up in the rear shoes.

K

BuckTruck16 · 10-14-2012, 08:47 PM

Thanks Keith, your always there to help me. Appreciate greatly!

motornut · 10-17-2012, 07:56 AM

on my 78/79 the larger line is the rear,smaller res hole
from the valve it goes two small to the fronts
1 large to the rear

10-10-2012, 06:55 PM	#1
BuckTruck16 Registered User Join Date: Nov 2011 Location: Pottstown Pennsylvania Posts: 42	Master Cylinder line issues We have a '79 k10 with a 5.7L, with a disc/drum setup. We just replaced all the lines but are not sure what lines go to what. As in, the master cylinder has 2 ports. The one in the front is larger than the one in the back. Is the bigger port in the front for the front breaks or rear? And which one goes in which for the proportioning valve? -Thanks

10-11-2012, 08:51 PM	#2
BuckTruck16 Registered User Join Date: Nov 2011 Location: Pottstown Pennsylvania Posts: 42	Re: Master Cylinder line issues Any luck?

10-11-2012, 09:09 PM	#3
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,226	Re: Master Cylinder line issues The larger part of the reservoir, regardless of whether it is at the front or the rear of the master cylinder, goes to the front discs. This is because the disc brake pistons take more fluid to actuate than the rear wheel cylinders. I believe that same brake line goes into the proportioning valve because it has a "hold off" feature which keeps the discs from applying until the slack has been taken up in the rear shoes. K __________________ Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/

10-14-2012, 08:47 PM	#4
BuckTruck16 Registered User Join Date: Nov 2011 Location: Pottstown Pennsylvania Posts: 42	Re: Master Cylinder line issues Thanks Keith, your always there to help me. Appreciate greatly!

10-17-2012, 07:56 AM	#5
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: Master Cylinder line issues on my 78/79 the larger line is the rear,smaller res hole from the valve it goes two small to the fronts 1 large to the rear Attached Images __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.