Scott_Hower
Luke Skywalker
Offline
I've been using silicone/DOT5 brake fluid for a few years now. I have a small fortune invested in the Glasurit paint job and refused to take any chances with it.
As luck would have it, I've had a persistant brake fluid leak that I could not seem to trace. After about a month or two, the MC reservoir would be half empty with no obvious trail of fluid. No wet floormat, no garage floor puddle, nada. Pedal was pretty firm, so I had brakes (DOT5 is spongier to begin with). Drove me bonkers.
I decided to get serious two weeks ago. I taped newsprint under every single brake fitting all around the car and let it sit for a few days, occasionally working the brakes. The culprit? The brake pressure differential valve; the little devil pictured here. One of the flare fittings had a burr in it that distorted the brass seat and refused to seal. I discovered a drip would appear when pressing hard on the pedal. I filed the burr down with a tiny swiss file and tried to refit it. No dice, still dripped, it spit fluid now, even worse. I ordered a rebuilt one from University Motors Ltd/John Twist. I fit the new one last night (after checking/burnishing all of the flares) and so far all is well, although I have yet to STAND on the pedal as in an emergency stop.
What a freaking relief; I've been chasing this for at least a year or two. Photos is the rebuilt unit showing no sign of a leak (yet). Cross your fingers...
As luck would have it, I've had a persistant brake fluid leak that I could not seem to trace. After about a month or two, the MC reservoir would be half empty with no obvious trail of fluid. No wet floormat, no garage floor puddle, nada. Pedal was pretty firm, so I had brakes (DOT5 is spongier to begin with). Drove me bonkers.
I decided to get serious two weeks ago. I taped newsprint under every single brake fitting all around the car and let it sit for a few days, occasionally working the brakes. The culprit? The brake pressure differential valve; the little devil pictured here. One of the flare fittings had a burr in it that distorted the brass seat and refused to seal. I discovered a drip would appear when pressing hard on the pedal. I filed the burr down with a tiny swiss file and tried to refit it. No dice, still dripped, it spit fluid now, even worse. I ordered a rebuilt one from University Motors Ltd/John Twist. I fit the new one last night (after checking/burnishing all of the flares) and so far all is well, although I have yet to STAND on the pedal as in an emergency stop.
What a freaking relief; I've been chasing this for at least a year or two. Photos is the rebuilt unit showing no sign of a leak (yet). Cross your fingers...