Brake fluid question

[malcolmbuck]

Just fitted the brake pipes. The manual says dont use silicon type brake fluids.

So what do people use? Presumably mineral but what brands are commonly used?
Also how many litres do I need?
And what DOT spec do I need?


Many thanks,

Malc

PS fitting the rear nearside brake pipes was a sod. Next time do it without the diff in the way!!

[maxGD059]

Rob's amazing sponsored links below your post temporarily provided the answer -Dot 5.1 is the highest spec non silicone based brake fluid. how much you need depends on how good you are at bleeding the brakes. My guess is you will need 1 litre but if you buy 2x500ml bottles & have one left, you can get a refund. HTH

[JonnyT]

Depends what system you are running. There is a thread on here - different fluids have different properties as far as I recall - it is not just a case of the higher the number the better the product.

In terms of quantity - I got through 5ltrs trying to blead the brakes on the dax de-dion but I suspect it can be done more easily.

[bogster]

Originally Posted by malcolmbuck

Just fitted the brake pipes. The manual says dont use silicon type brake fluids.

So what do people use? Presumably mineral but what brands are commonly used?
Also how many litres do I need?
And what DOT spec do I need?


Many thanks,

Malc

PS fitting the rear nearside brake pipes was a sod. Next time do it without the diff in the way!!

Hello Malc,

Handy little link attached. DOT 4 - Wikipedia, the free encyclopedia

I used DOT 4 and I've been stopping fine now for over a year.

[Marty V6]

My Cobra had silicon fluid in it when I got it - I've since had to replace both rear drum pistons and the master brake cylinder. when I opened them all up, the rubber piston seals were turning to mush. Unless your system is specifically designed for this 'orrible stuff I would stay away from it.

Needless to sy, I now dont have this stuff in the system any more. I got a 5 litre tub of either dot 4 or dot 4.1 (cant remember which now) from Halfords and pressure bled the whole system - I had to pressure bleed the system cos silicon fluid floats on top of normal brake fluid, so when I was manually pumping the brakes, I was never getting the fluid moving quick enough to get rid of it entirely.

Never had a problem with it since.

Cheers

Marty

[dingocooke]

Older hydraulic systems are generally better with DOT4 than DOT 5; due better lubrication properties of DOT4. DOT5 is higher heat range so good for track day extreme temps, but in normal use DOT4 will mean less sticking of components and less likeliehood of piston seizure when exposed to road crud salt damp etc