Sounds like a sticking servo. Quite often the black neoprene(?) ring that
holds the main/big piston in tight against the bore is too big and won't let
the piston move. Have a look. If you get the feeling that the servo has
recently been rebuilt, then the neoprene ring becomes more of a suspect.
People cut them down &/or put some grease in there. (Not any old grease. The
servo man over here sold me some black stuff and it works well).
I've been through this myself!
Simon
-----Original Message-----
From: healeys-bounces@autox.team.net [mailto:healeys-bounces@autox.team.net]
On Behalf Of gturl@sympatico.ca
Sent: 29 April 2013 15:36
To: healeys@autox.team.net
Subject: [Healeys] BJ8 Brakes not releasing
Our BJ8's (Phase II) brakes are not releasing properly.
We acquired the car last summer and the brake issue developed over about a 6
week period. It got so severe we had to take the car off the road. The rear
wheels (drums) remained cool but the front wheels (discs) got too hot to
touch after just a short city drive.
Since then I have...
- Replaced the brake fluid (by bleeding the brakes until the fluid "ran
clean")..
- Replaced the rubber bits in the calipers..
- Replaced the pistons in the left side caliper assemblies.. (the right side
pistons seemed to be fine)..
- Replaced the flexible hoses to the front brakes..
Although the car had been very well looked after by the previous owner, my
understanding is it had not been driven very much at all over the last 5
years or so.
The interesting thing is that with the engine not running, the brakes
release properly. With the engine not running and the car on a slight slope,
regardless of how hard I apply the brakes, it will start to roll as soon as
I take my foot off the pedal. With the engine running however, after I apply
the brakes and remove my foot from the pedal, the car will not move. If I
let sit, after 3 or 4 minutes the brakes will release and the car will start
to roll. I observed the same behaviour late last summer once, although I
only had to wait about 30 seconds.
Other symptoms are..
- Thebrake lights go out when I take my foot off the brake as one would
expect, even when the brakes have not released.
- I had replaced the brake fluid before I replaced the rubber bits in the
calipers, but I still found a lot of "junk" in the fluid in the calipers.
- We do not appear to be losing brake fluid.
My "prime suspect" at this point is the vacuum booster itself. To be more
specific, I suspect there may be dirt or other contaminants in the fluid in
the booster, or possibly lack of lubrication somewhere.
Before I go any further, any thoughts/comments/suggestions on further tests
or flushing the fluid without disassembly or other possible causes would be
appreciated.
Geoff and Carol
$12.75
Archive: http://www.team.net/archive
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
http://autox.team.net/mailman/options/healeys/simon.lachlan@homecall.co.uk
_______________________________________________
Archive: http://www.team.net/archive
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
|