[Healeys] heavily dragging brakes on 100 after using silicone brake fluid

[T+ B Willig]

Hello,

 

in the archives of this list you can find an e-mail of Jim Leblanc related
to this problem:

 

>>>>>>>>>>>>> 

In reply to an inquiry I will openly post an answer.

This problem I describe with silicone brake fluid applies only to 100-4's,

as far as I know.

The problem I noticed was dragging of the wheels with overheating of the

brake drums. Upon inspection I noted the master cylinder was failing to

release fluid. The pedal height and play at the push rod were excessive. The

piston was sticking. Also the brake lights stayed on. (pressure in the

system)

According to Roger Moment's article, the piston must release an additional

0.062 inches to permit the master cylinder bleed holes to operate.

To accomplish this, the pusher piece needs to be machined to remove 0.062

inch. The pusher piece is the first part behind the push rod and first

inside the retaining clip. See an exploded view of the master cylinder.

Best Regards,

Jim LeBlanc

1956 100-M

>>>>>>>>>>>>>>>>>>> 

I am facing the problem of dragging brakes exactly as described above. My
BN2 received a full brake overhaul (new cylinders, calipers, brake hoses and
brake lines) about 12 months ago. Until last Friday all was well.

I just wonder why this problem only occurs when using silicone brake fluid
are the rubber parts swelling in silicone brake fluid? 

Please enlighten me.

 

Best regards

 

 

Thomas Willig