Re: Remote brake fill kits

Posted by Ross On 2014/8/21 20:28:45

The rear seal has air on one side, and fluid on the other once some fluid sloshes over from the main reservoir or the hydraulic seal leaks a tad. So it is sealing a fluid at atmospheric pressure, or at worst a pressure differential of approx 6 psi when the vacuum canister sees full manifold vacuum during a panic stop. The fluid provides lubrication for what amounts to a piston rod packing for a vacuum cylinder. Adding the pressure of an 18 inch high column of fluid is inconsequential--the approx height of the remote reservoir above the Treadlevac.

I have customers who have run those reservoirs on their cars for years with no problems.

In the 40 or more BTV I have rebuilt over the years there is never anything esoteric or bizarre in the failures. There is improper assembly such as seals in backwards. There are rusty or pitted pistons that rip the seals up. Those things cause fluid loss to the vacuum side to varying degree. The instantaneous failures are almost always due to brake fluid that has broken down to the consistency of Gravy Train--the lumps hold the compensator open.