[Healeys] Master Cylinder

[Peter Linn]

Hi Keith

As you know I've had constant problems with bleeding the brakes on the Ward 
Spl. One thing to check is that there is sufficient free play at the pedal. 
If the pushrod is too long, it's possible that the piston doesn't return far 
enough to clear the hole in the cylinder that allows fluid to flow down from 
the reservoir.

If this is OK, the other issue is that air can be sucked in via the end seal 
on the piston when the pedal is released, as the hole from the reservoir is 
small and with everything ewlse in good condition, the suction created when 
the pedal is released can draw air via the seal. I eventually got a pedal by 
(a) instead of closing the bleed screw after a down stroke, ensure the bleed 
tube is full of fluid, and that it rises vertically from the bleed screw. 
Wait for air bubbles to rise far enough that they won't get sucked back in , 
then SLOWLY relase the pedal. Repeat until there's no more air bubbles. This 
way, fluid gets drawn back in via the bleed screw rather than air elsewhere.

Cheers

Peter

----- Original Message ----- 
From: "Keith Bailey" <keithbailey5 at bigpond.com>
To: <Healeys at autox.team.net>
Sent: Friday, June 18, 2010 5:52 PM
Subject: [Healeys] Master Cylinder


>    I am experiencing problems with my (suspect) Master Cylinder on my BN1
>    With the Master Cylinder on the bench in a vise with the reservoir
> connected
>    to inlet with oil in it and the outlet connected to a pipe which is
> blanked of
>    there is hard pressure. When fitted back to car there is no pressure 
> when
> attempting
>    to bleed brakes all the wheel cylinders are new.I feel sure the problem 
> is
> in the Master
>    Cylinder but lost for answers
>      Regards Keith