Brake problems Aurelia & Appia

[Erik]

Dear Lancia-friends,
The brakes of our Lancia's (my Aurelia B 20 GTS 5° serie and Hans' Appia 3° serie) are sometimes not reliable and are 'gripping' at unpredictible moments. The brake-pedalpoint is displacing from the normal stand (middle) to the top of the pedal. The more on the Aurelia, the clutch-pedal (hydraulic circuit) is suddenly going down to half a stroke.
This phenomen is apearing by an oildispenser under normal pressure and with no or few pedal-use.
In my opinion, but also by experienced mecanics, the brakingshoes are correctly mounted: there is no friction in normal conditions and the brakes are working synchronically on the 4 wheels (the B 20 was tested on a brake rollertestbench).
I hope that someone outside can help us, because we don't understand the problem !!
Greetings, Erik (en Hans)

Erik Vermaelen
Voorspoedlaan 13
B 1700 Dilbeek
Belgium
Tel: +32/2/569.36.19
Gsm:+32/476/42.74.70
e-mail: erik.vermaelen@skynet.be

[Brian Long]

I am not sure if this will help but I understand that there is a compensating drilling in the master cylinder adjacent to the hole which is connected to the reservoir.
I have not determined how this works but I do know that it is necessary that both of the holes are clear of the actuating cup (rubber) in the master cylinder when the brake pedal is fully retracted.

[Erik]

Brian,
Thanks for your quick reply.
We mounted last year a new master brake cylinder and I think that the holes are still clear.
Maybe there is a problem in the oildispenser or in the master clutch-cilynder; we have to look at it.
Kindest Aurelia-greetings, Erik

[Huib]

The point is that the plungers must retract fully for the cups to clear the holes. You have to make sure the pedal has a few mm of free play before the pin hits the plunger.

[Erik]

Hoi Huib,

Thanks for the reply - I will check the free play.

Aurelia greetings, Erik