On the way home from work the servo assist failed: braking required a hefty stomp and was accompanied by a pulsating noise from the servo unit.
1. no fluid leaks anywhere
2. the vacuum hose is OK
3. when the hose is disconnected from the servo while the engine is running a pulsating suction can felt
What's next in the diagnosing procedure ? Check valve ? And after that ?
Many thanks.
Sounds to me that the bladder in the servo has got a hole in it. If so, the only way to fix is replacement. I have a spare one if you are interested that works.
GTV Veloce, will do further diagnosing tomorrow.
Do you have a replacement servo unit or just the membrane ?
Just the servo unit as a whole. I had one that went once and everything I read and was told was don't bother trying to repair them. The spare one I have came out of my donor car (83 GTV) and was working fine.
what's the secret to refitting the seals in the master cylinder without damaging the seals' lips ?
The secret behind not damaging the seal lips is to be very carefull when refitting them, use rubber brake grease and, if possible make up an aluminium tapered lead intool to guide the seals onto the piston and a aluminium tapered sleeve to help the pistons and seals enter the master cylinder bore without getting knicked, BUT first of all, get a price on a new master cylinder, as they might be cheaper than what you think, however rebuilding the master cylinder is a good experience, if done properly, Colin.
as you guessed I am doing it for the experience, after all seal kits are available and therefore there must be an installation procedure, it may not be easy ... see how it goes.
Every time you fix something, you learn something and its more information you can store for the future, so you can relate it to another job in the future and you get to spend more quality time in the shed tinkering with your car, Colin.