After receiving several notes: Again I caution BN-1 and BN-2 owners about
using silicone brake fluid without making proper modifications.
Reference: Austin-Healey Magazine December 2003, Silicone Brake Fluid &
Brake Hydraulic Systems, Roger Moment
Quotes:
"But among Healey owners, the problem seems to be limited to the 100. In
fact I had driven my 3000 for some 15 years using silicone brake fluid
without any such problem occurring."
"So what keeps the brake fluid from returning to the master cylinder . . .
?" ( problem I experienced )
". . . the piston must travel an additional 0.062 inches or so before the
bleed hole clear(s) the seal lip. . . " ( modification made to mine )
Yes there is a difference between the 4 and 6 cylinder cars, it is the
master cylinder. The article tells how to make the simple modifications. Few
articles are this well written. All BN1/2 owners should read this before
putting silicone fluid in their car.
I also believe the same master cylinder is used on some Bentley's and so the
same problem likely lives there too!
Best To All,
Jim LeBlanc
1956 100-M (modified master cylinder and silicone fluid)
-----Original Message-----
From: owner-healeys@Autox.Team.Net [mailto:owner-healeys@Autox.Team.Net] On
Behalf Of Jim LeBlanc
Sent: Monday, December 20, 2004 5:58 PM
To: healeys@Autox.Team.Net
Subject: RE: brake fluid
Cautionary note to all BN1 and BN2 drivers.
Using silicon brake fluid has been known to slightly swell parts in the
master cylinder. This causes a failure in the pressure release passages.
(Not certain I am describing this correctly.) Then end result is that your
speed is greatly reduced and those brake drums get smoking hot.
This condition is relieved with some additional machine work done to the
master cylinder. I sent mine to White Post and they knew the subject.
Yes I believe in silicon brake fluid and for all the right reasons, but look
into this subject and form an opinion for yourself.
I have never heard of a problem using silicon brake fluid with cars made
after the BN2's.
Best Regards
Jim LeBlanc
1956 100-M
-----Original Message-----
From: owner-healeys@Autox.Team.Net [mailto:owner-healeys@Autox.Team.Net] On
Behalf Of davidwjones
Sent: Monday, December 20, 2004 2:29 PM
To: James Shope; healeys@Autox.Team.Net
Subject: Re: brake fluid
Jim,
I don't know whether current rebuild kits are ok with std brake fluid or
not.
In order to avoid the question altogether, I have used silicon brake fluid,
which absorbs less moisture than the others, and has the added benefit of
not
eating paint if it leaks or spills.
Some claim that the silicon fluid gives a spongier pedal, but I have not
found
this to be so.
David W. Jones
'62 Mk II BT7 tricarb
Cumberland, RI USA
----- Original Message -----
From: James Shope
To: healeys
Sent: Monday, December 20, 2004 11:18 AM
Subject: brake fluid
after destroying my complete brake and clutch system some 30 years ago by
using american brake fluid, i was told that the british used live rubber
and
therefore you had to use ester based fluids, i.e., castrol or lockheed,
etc.
i
have been told that the brake and clutch parts are now made of neoprene or
some such synthetic and that american(petroleum based) fluids are ok. i
still
only use castrol but am i wasting my money or being smart? healeymanjim
|