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brake fluid
bill132hotrod - 28/4/08 at 07:12 PM

Hi all The question is which Brake fluid to use in my new luego running a full race C20XE, ive been told to use silicone, but which one and where do i get it ? cheers BILL.


Mark G - 28/4/08 at 07:22 PM

you can use silicone if you want to, be sure not to mix it with normal brake fluid though as they don't get on well and results in poor brakes.

Brake fluid you would find in a road car is Dot 4, Dot 5.1 has a higher boiling point and is better for faster applications. I don't know much about silicone fluids but I think its also knows as Dot 5.

I'm going to use dot 5.1 in my indy when ready for it.


meany - 28/4/08 at 07:25 PM

tell me if im talking crap here....lol

dont use silicone unless your brake system is spec'd for it.

Dot 5 is silicone
Dot 5.1 isnt.


mookaloid - 28/4/08 at 07:50 PM

I have been a fan of DOT 5 (silicone) for a long time. I used it in my Indy. It works fine for vehicles which don't do a high mileage and which might stand around for long periods (say laid up over winter)

You should only use it if all the components are new and have not been exposed to mineral fluid.

Ordinary fluids DOT 4 or DOT 5.1 are ok but they do attract moisture which can lead to corrosion of the components. They should be changed every couple of years but do give slightly superior performance if you are racing say.

A bit of a controversial subject but hope that helps.

Cheers

Mark


chriscook - 28/4/08 at 08:39 PM

quote:
Originally posted by mookaloid
You should only use it if all the components are new and have not been exposed to mineral fluid.



Bear in mind that new components may have been assembled using conventional fluid and even that small amount can cause big problems.....


coozer - 28/4/08 at 10:50 PM

Halfords 5.1 here. Not sure why but better than the normal stuff??


britishtrident - 29/4/08 at 12:35 PM

After 12 months in the UK climate the boiling points of DOT 5.1 and DOT 4 are only a few degrees different.

The higher the boiling point when new of a conventional glycol ester brake fluid the more hygroscopic it is. Racing fluids are more hygroscopic than DOT 5.1 which is more hygroscopic than DoT 4.

DoT 3 fluid is pretty well history now and mainly restricted to the USA.

[Edited on 29/4/08 by britishtrident]


britishtrident - 29/4/08 at 12:41 PM

quote:
Originally posted by chriscook
quote:
Originally posted by mookaloid
You should only use it if all the components are new and have not been exposed to mineral fluid.



Bear in mind that new components may have been assembled using conventional fluid and even that small amount can cause big problems.....


Yes because conventional glycol ester fluid is hygroscopic and DoT 5 isn't its the small pockets of conventional fluid that will contain any moisture that gets into the system.


MikeRJ - 29/4/08 at 12:59 PM

DOT5 (silicone) is also excellent at holding air bubbles, which means that you nearly always get a softer pedal than with glycol based fluids.

The fact that major players such as AP don't recommend using silicone fluid in their products is reason enough to avoid it IMO.


[Edited on 29/4/08 by MikeRJ]


bill132hotrod - 29/4/08 at 09:30 PM

Cheers guys thats a great help thanks again. BILL