Brake Fluid

[myoldjalopy]

I'm gonna have to bleed my brakes - anyone know how much brake fluid I will need to do this properly and not run out part way through?

[kevin s]

A litre should be more than enough.

[myoldjalopy]

Thank you, Kevin. Any thoughts on whether the brakes should be adjusted normally when bleeding, or locked up? I'm sure I have heard of people doing it both ways but can't see why it would make any difference, except that when locked up the cylinder piston can't move out when the pedal is pushed down?

[les]

I don’t know about being locked up but they should be adjusted maybe just binding, have you considered silicone fluid. I’d us nothing else on a minor.

[oliver90owner]

Handbrake applied will sort out the rears. Bleeding is fast down and slow up, with the pedal if bleeding with two people. No point in risking the shoes possibly allowing air back down the line while closing the bleed nipple? I expect it would simply possibly mean using/losing more fluid than necessary.

[Chill59]

I don’t know about being locked up but they should be adjusted maybe just binding, have you considered silicone fluid. I’d us nothing else on a minor.

Why is silicone better in a minor Les?

[oliver90owner]

Why is silicone better in a minor

The technical response is that silicone types, unlike glycol types, are non-hygroscopic.

[myoldjalopy]

Yes, so you don't have to change it like ordinary brake fluid. But from other posts on here and elsewhere, there seems to be divided opinion on silicone v. ordinary fluid with some saying silicone is harder to bleed and gives a softer pedal. A bit like the perpetual points v. electronic ignition debate....or Champion v. NGK spark plugs. I suppose it depends on your actual experience - good or bad - as to whether you recommend something or not.

[alanworland]

Only had good experiences with silicone - filled in early 2000!

Alan

[kevin s]

Silicone fluid is a contentious issue, the advantages are it is not hydroscopic and doesn't damage paintwork, disadvantages are it has a slightly lower boiling point than new dot4 (only an issue on high performance cars and dot 4 is worse when it has water in it), costs more and some people claim it has caused seals to swell if a system has been used with dot4 (they are supposed to be compatible though).

My personal summary is if you change dot4 as recommended every couple of years it doesn't make a lot of difference and at least your bleed nipples stay free, I wouldn't put it in a system already wet with DOT4 or a modern with complicated ABS either.

[paul 300358]

I have midget disks on the front. When I fitted new callipers about 2 years ago the paperwork clearly stated that they are not suitable for silicon fluid. I don't know if its the seals which are the problem.

[King Kenny]

I run with Ford disks and I have not changed my Silicone fluid for 10 years. Before I hade to refurbish the rear cylinders every year. I replaced the whole braking system with copper/nickel pipes and filled it with Silicon brake fluid about 25 years ago. Never had a problem in all that time. Used it on my Honda CB400T.