Brake master Cylinder

[markm]

Right before I do something, looking for a bit of advice/ confirmation from the DDK knowledge bank.

For the last couple of years I've gad a long soft brake pedal. Bled the system but it still ends up coming back. So thought to myself maybe I have a leak. Removed the belly pan and no signs of a leak


So next thing is master brake cylinder seals might possibly be worn. The car is 41 after all.

So my question, do I just disconnect the cylinder as shown in the shot, replace the rubbers on the piston, re-assemble and refill & rebelled the system.

[Lightweight_911]

If you suspect the master cylinder I'd buy a new one rather than rebuilding your existing one.

[MT]

I got mine from this lot. £69 less 35% at the moment. Genuine ATE.

http://www.mister-auto.co.uk/en/master- ... _g258.html

Mick

[markm]

So is that just a drop off and on

[markm]

If you suspect the master cylinder I'd buy a new one rather than rebuilding your existing one.

I'm not 100% sure it is, just a process of elimination, no visible leaks anywhere but the pedal keeps going soft, so I thought it must be the cylinder.

If anybody has any other thoughts I am open to them

[Lightweight_911]

When was the last time the brake fluid was changed ?

[markm]

When was the last time the brake fluid was changed ?

Winter 2010

[davep]

My experience when I used the car as a daily driver was that the MC lasted about 8 years, and most often leaked into the pedal cluster. I always changed the fluid twice a year, certainly before track season and winter. I learned the best way to get a full flush was to drain the calipers since a simple bleed would not change the fluid in the outer halves unless the caliper had a cross-over tube and an outer half bleed nipple. The bore of the MC is often corroded by water in old fluid (one year old) so new seals would not likely work by themselves. Rebuild kits are rare enough let alone new seals.