DOT-3 vs DOT-4

Yeah, that's about right. Dot4 is more expensive than Dot3 but it is also better in terms of boiling point. Both absorb water so you don't open the pot until you are ready to use it.

Dot5, just to be particular, is silicone and you can't mix it with the other ones. It used to eat seals by reputation* but the later versions may be ok. I'd say use Dot4 just to be on the safe side, especially as it is you Brian as you seem to be remarkably unlucky in cars.

(* - Much like a killer whale.)

Yep, Dot 5 is silicon, and incompatable with DOT3, and 4, but DOT5.1 is fully compatable with 3 and 4.

Confusing isn't it.

According to BS, all later DOT fluids are compatible with earlier ones and may be mixed if the earlier standard is OK. Make of that what you will...

hmm, I wouldn't be the one to try it. Not with brakes anyway.

Yeah that's true, don't take risks when it comes to brakes and tyres.

Hey guys, my Gold Eagle DOT-3 fluid filled brake system seems to feel different then the day I got them into my system. The pedal feels longer now and the brakes seem to 'bite' more rather than produce a gradual braking force effect.

Could this be caused by the heat altering the molecular properties of the DOT-3 fluid or something? because I've been pushing the car really hard.

Thanks.

If you boil brake fluid, it ends up knackered. I seem to remember the boiling point drops and it might become compressible. OTOH, if you swapped disks and pads at the same time, it's probably just them getting worn in as opposed to being s**te when they're new.

In article , happyguy_spam snipped-for-privacy@microsoft.com spouted forth into uk.rec.cars.modifications...

Yep, hard use will boil it, and lower the boiling point each time, but also with time, water gets absorbed, and water can compress, where the fluids can't. Also water boils at a lower temp as well.

DOT3 is crap. DOT4 is better. DOT5.1 is the best.

Avoid DOT5 - it's silicone-based, and won't mix with your existing fluid.

The price difference between them all is minimal, so it makes no sense to use anything less than DOT5.1

You've boiled the fluid, and now it's shafted.

Bleed the brake system and continually add some fresh DOT5.1 - repeat until you've completely replaced the old fluid. If you're not comfortable with doing that, it's a trivial job for your local garage.

Sure, but it's less trivial to do when you have ABS, it turns out.

Depends on the system.

My ABS-equipped car is bled in exactly the same way as a non-ABS one. You only need to bleed them differently, if the ABS setup has a seperate reservoir for the high-pressure pump (or something along those lines !)