Vacuum brake vacuum line

[ttypewhite]

This thread is for those that did a vacuum brake conversion but your brakes still feel soft. When my Powermaster went south on me, I converted to the vacuum brake deal and also changed the brake pedal to the one with the correct ratio. I bled the system and they worked, not not good. They felt soft and needed to be pumped a couple times to work decent. So I started trouble shooting it, and started with the master cylinder. I bench bleed it first, then bled all 4 corners multiple time with the same results. I didn't like the idea of the rubber hose going from the vacuum brake to the intake. So I decided before I buy another master, I was going to replace the line and brake check valve first because the rubber stuff looked odd under my hood.

I have drilled and taped my 1" spacer for the vacuum source with is the rubber line at the back of the intake.

I was looking through the Summit Racing catalog and saw this check valve for the master. Part# is on the box

I made up my own line using #6 line and Russell fittings (#6 straight and #6 90)

Installed it on the car

Then I took it out of the garage and gently touched the brake pedal and the difference was night and day. The car stopped very aggressively and worked perfectly. I would advise guys to try out a new line and check valve before throwing in the towel.

 

[larrym]

Looks great cool idea.

 

[gusszgs]

Thanks for posting this. Probably make this upgrade next spring

 

[nonosv6]

Mike, great write up as per usual. What do you think the increased performance is do to? Better source of vacuum or the stiffer braided line or maybe combo of both?

 

[ttypewhite]

Mike, great write up as per usual. What do you think the increased performance is do to? Better source of vacuum or the stiffer braided line or maybe combo of both?

I believe it is the increased vacuum, for all I know the plastic check valve that came with the master could have been the issue.