Have A Brake Problem! Please Help

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Wed 4 Feb 2004 16:44
Have A Brake Problem! Please Help - CardiffCityFan
I have a shadow 1 (1972) with a brake problem that I am unable to solve. Can anybody give me any advice please?
I replaced the two n/s/r flexi brake pipes closest to the calliper. Unfortunately there was a fluid leak o/night which emptied both reservoirs. On bleeding the system fluid was drained on both rears until no air was evident, however the brake pedal travels to the floor still. When pumped the brakes are good but when this ceases the pedal goes to the floor. The front brakes have now been bled. No air was evident but the problem remains. The warning display, when the brake pedal is applied shows ?partial brake failure? and ? master cylinder? warning lights. Brakes are good when pumped but the obvious problem is air is still in the system. (Possibly in the master cylinder)
Can anybody give me any advise on this problem?
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Wed 4 Feb 2004 17:13
Have A Brake Problem! Please Help - SjB {P}
My starting point based on the info given would be that the piston seals in the master cylinder are worn.

Pumping the pedal is causing enough pressure to force the seals to make good contact with the bore, but when not, they relax, and allow brake fluid to seep past their sides.

Just my 2p as one who had a similar problem on a car I owned in years past, but someone more familiar with your system may be along in a minute!
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Wed 4 Feb 2004 17:14
Have A Brake Problem! Please Help - SjB {P}
My starting point based on the info given would be that the piston seals in the master cylinder are worn.

In fact, to be clear, in the case I wrote about, it was the master cylinder bore that had worn, too, so even new seals didn't seal, if you see what I mean!
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Wed 4 Feb 2004 18:33
Have A Brake Problem! Please Help - Civic8
>>there was a fluid leak o/night which emptied both reservoirs.
I assume you didn`t see where the loss was from?.If you cannot actually see a leek it is more than likely it is draining into the servo in which case a new master cylinder is wanted.
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