Is anyone running a residual valve on their brake systems? I'm having some pedal bleed down. Have to pump pedal after a bit. Thinking I might need a residual valves.  7/8 Willwood master cylinder was stoptech brakes.

Is anyone running a residual valve on their brake systems? I'm having some pedal bleed down. Have to pump pedal after a bit. Thinking I might need a residual valves.  7/8 Willwood master cylinder was stoptech brakes.

Typically, as long as the master cylinder is higher than the brake calipers, when you have some pedal bleed down, there is some air in the system. Using a power bleeder that pushes the fluid & air out of the lines & back in the master cylinder reservoir is the best way to fix it. If you try & just can't get it, running 2# residual valves is a fix. Not ideal, as it it creates a little drag in the brakes.

Awesome will try the power bleeder.
Thanks Ron

We run them on street driving applications when the calipers are higher than the master cylinder reservoir. But as Ron mentioned if you are trying to race with them they will not let the brake cool properly due to the little bit of drag left in the system. It has been by experience that the pumping you are referring to could be being caused by brake knock back.   

Ok I haven't power bleed the brakes yet. Iam running stoptech brakes on a 67 fire bird did not think about knock back thanks for the information I will definitely check into that. Thank you.

Ok I haven't power bleed the brakes yet. Iam running stoptech brakes on a 67 fire bird did not think about knock back thanks for the information I will definitely check into that. Thank you.

Scot is spot on about knock back. I don't "think" you're experiencing knock back in the StopTech calipers, as I designed those with 6# of anti-knock back spring rate on each piston. But it's still possible.  Power bleed the master first.  Then run it & see.

Sounds good   Haven't been able to bleed yet.  snowing today in Colorado