S3 E-Type

Rebuilding the Brake Servo
Seal Replacement

by Administrator

The Servo is an important part of the brake system & at risk of internal malfunction. If you keep adding brake fluid then most likely the servo is consuming it....

The vacuum portion of the servo is secured by the metal band and comes apart quite easily:

You are then confronted by the rubber diaphragm, this can be removed to leave a large plastic disk on the end of the operating rod, held in place by the spring pressure behind it. In the centre is a small black plastic disk, if you look carefully around its edge you'll see the end of the metal key that holds it together.

If you gently push the plastic disk against the spring pressure then this key is released and can be removed:

Now you can see the spring (and in this case the final resting place of all that brake fluid):

The hydraulic system can now be unbolted and the first rod & seals can be removed.

To remove the second rod a small pin must be removed from the base of one of the hydraulic line connections:

Below the parts in the rebuild kit (with the exception of the diaphragm):

and here's the parts pre-assembled ready to be fitted back to the bore:

That small leakage of brake fluid had probably accumulated over some time, but eventually it can damage the diaphragm and start to get picked up into the vacuum system creating smoke out the exhaust as the fluid is sucked in thru the engine. With mineral fluids such an occurence is annoying, with Silicone brake fluids that is catastophic!! As I know to my cost (on a Triumph TR4A) when that silicone is burnt in the engine it forms Silicon Dioxide... aka Sand...within 1000 miles all the piston rings fail.....ugly.
Rebuilding the Brake ServoAnonymous|26 Jul : 16:06

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very helpfull best seen on brakes great pictures can now do the above asap

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