Author Topic: brake fluid ? (Read 2913 times)

richard · « **on:** June 30, 2006, 11:11:50 AM »

hello there, i have just replaced my master brake cylinder and all brake lines and hoses

can anybody now tell me what type or spec of brake fluid to use and how much you think i will need for the job , of replenishment

on my 1972 fiat 500l

reguards

richard

PaulB · « **Reply #1 on:** June 30, 2006, 02:28:40 PM »

DOT 3 is the type used in the 70s - it has problems - absorbs moisture easily, boils a bit too readily and strips paint. Its also getting harder to find.

DOT 4 will be fine and is more readily available. It offers improvements in the short term, but is worse when old (it boils more readily than DOT 3 when its contaminated with water, but it absorbs water more slowly, if that makes any sense).

Either way - its best to change the fluid every two years to be safe - likewise, don't use brake fluid that's been opened for long.

I've read that DOT 5 may attack the rubber in the cylinders and hoses - don't know if that's true, but its expensive anyway, full of air and I avoid it (its also unsuitable for ABS so i really don't know who uses it?).

DOT 3 and 4 can safely be mixed, but never with DOT 5.

Hope this helps!

I've always found a standard bottle (1 litre?) more than enough to flush and fill the system.

Nurudin · « **Reply #2 on:** July 04, 2006, 12:57:34 AM »

I was thinking of changing my brake fluid. Can any one tell me the best way to do it? Do I just let it bleed, and then fill back up?

PaulB · « **Reply #3 on:** July 05, 2006, 02:33:14 PM »

Start at the wheel nearest the master cylinder, and work back doing the furthest last.
Just pump new fluid through until its clean and bubble free - make sure the reservoir doesn't run out our you'll need to start again.
Use a "one man" bleed kit - it saves a lot of time and frustration.
Its much quicker and easier with the wheel off.
Also make sure the fluid is fresh and bubble free before using it.

ChrisRLewis · « **Reply #4 on:** July 05, 2006, 02:42:26 PM »

yes make sure the brake fluid is bubble free!
It's a very common mistake to shake the can of brake fluid just before using it.

Bruce · « **Reply #5 on:** July 05, 2006, 06:25:28 PM »

get a one man bleeding kit, they are pretty cheap and use the spare wheel to presurise the braking system. they are very easy to use and are great for changing fluid aswell. aslo it is a lot quicke rthan the usual 2 man job.