No Brakes on my 407

Nick Challacombe · #1 (**permalink**) 26-04-23, 11:45 AM

Good day fellow Bristolers.
I went to remove my 407 from its garage and it started first turn, put my foot on the brake pedal and it went straight to the floor. Looked under car, no sign of a leak. Undid big brass filler nut on the lockheed master cylinder, no brake fluid at all.
Moved car out of garage which has a tiled floor and drip trays, no sign of brake fluid. I filled the reservoir and pumped the pedal and had some resistance but on releasing the pedal air bubbled up out of the reservoir. Still no sign of fluid anywhere.
Any ideas, has the fluid been sucked into the servo? or the vacuum tank , I am baffled, the fluid I put in the master cylinder is still there, I can still pump the pedal and get resistance and the brakes hold but when I take my foot off the pedal air rushes out of the reservoir. No sign of damp on any of the calipers.

Please help, Nick Challacombe.

Geoff Kingston · #2 (**permalink**) 26-04-23, 01:23 PM

Nick,
Sounds to me like the servo may be the culprit and the fluid is leaking into the shell of the unit, if it was being sucked through into the engine you would see white smoke from the exhaust, I had servos on my 410 and 411 rebuilt as they were leaking internally, I had this done by past parts or Power Track Brakes (it was some years ago!)
This link while not specifically relating to the a Bristol may be of help or interest.
Geoff.
https://www.v8register.net/subpages/V8NOTE228.htm

Nick Challacombe · #3 (**permalink**) 27-04-23, 02:46 PM

Thank you Geoff, I contacted PowerTrack Ltd this morning and they are delivering a new servo tomorrow. The rebuild time was lengthy but an off the shelf new one was roughly the same money.
The forum is so useful, I should be able to get the car safely on the road for various Coronation events and the 50th Anniversary of the Ipswich to Felixstowe car run for over 50 year old vehicles.
Hope to see you soon.