Sounds to me like a non-return valve is leaking. I don't have a GT6, I have
a TR6, so I don't know if your brake master is one chamber or two. In any
event, there is a non return valve that is closed during brake application.
You will see exactly those symptoms, light pressure and the valve leaks back
into the reservoir, hard pressure and it really closes and doesn't leak. Its
rebuild time. Just did that same thing to my clutch master for the same
reason. Make sure the rubber pieces go back facing the same way as the old
ones. As to the bore I'd wait to see what it looks like.
Jim Altman jaltman@altlaw.com Illigitimi non Carborundum
http://www.altlaw.com/metro/jaltman.html 69-TR6#CC28754L(O) W4UCK
-----Original Message-----
From: owner-triumphs@autox.team.net
[mailto:owner-triumphs@autox.team.net]On Behalf Of
Aribert_Neumann@magna.on.ca
Sent: Friday, August 27, 1999 3:52 PM
To: triumphs@autox.team.net
Subject: Question - a sinking GT-6 brake pedal
In general, the brakes on my GT-6 work good (especially since I switched to
Hawk
HPS front pads - now I can actually lock the front wheels in a panic stop).
Problem: the brake pedal sinks very slowly if the petal is VERY lightly
applied
and the car is rolling slowly (i.e. creeping traffic on a gentle downhill
slope). The pedal has sunk to about double the distance (approx. 1 in. off
of
the firewall) as when the petal is applied with moderate to firm pressure
(normal stopping - pedal stops approx. 2 in. off of the firewall). The
pedal
does not sink when the car is not rolling - therefor does not appear to be
air
in the lines. The pedal does not sink when moderate to heavy pressure is
applied. Why? FWIW, the brake fluid level has not changed in the master
cyl.
and the runout on one of the rotors is about 0.008 in. over tolerance (but
not
enough to feel a pulse in the brake pedal).
It's been about 7 or 8 years since the last master cylinder rebuild so I am
planning on rebuilding the master cyl. this winter. Is there any advantage
in
having the bore in the master resleeved if it is not pitted? This is my
semi
permanent car and I expect to still have it in 10 years.
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