New Truck - '71 521

[Stoffregen Motorsports]

3 hours ago, andyZ00m said:

Any ideas why the brakes would lose fluid and get loose like that?

Install a residual pressure valve in the line between the master and the front (and rear) brakes. Even a small amount of residual pressure, like 2 psi, will help keep the wheel cylinder lip seals "energized" so they won't suck air and loose fluid.

 

I know you say you can't find leaks, but if losing fluid, it has to be going somewhere. Have you checked to see if it's leaking down the brake pedal inside the cab?

[andyZ00m]

8 minutes ago, Stoffregen Motorsports said:

Install a residual pressure valve in the line between the master and the front (and rear) brakes. Even a small amount of residual pressure, like 2 psi, will help keep the wheel cylinder lip seals "energized" so they won't suck air and loose fluid.

 

I know you say you can't find leaks, but if losing fluid, it has to be going somewhere. Have you checked to see if it's leaking down the brake pedal inside the cab?

 

I didnt see anything there or near the MS but I'll check that again just to be sure.

 

Im thinking its possible the new cheapo wheel cylinders might have leaked inside my drums too. I really cant find any fluid but I havent opened up the drums yet to see if thats what happened.

 

Will update when I have more info.

[Slow Loris]

15 hours ago, andyZ00m said:

 

Im thinking it’s possible the new cheapo wheel cylinders might have leaked inside my drums too.

That’s a good guess. I had this happen to a wheel cyl I bought off Rockauto. A good reason at least to switch to a dual master even without discs!