Brake fluid?

Rich H · Post by **Rich H** » Sun Jul 02, 2006 8:09 pm

Evening all,

Can someone explain the difference in brake fluids? I'm not entirely clear.

I have been using Castrol Response Super Dot 4 and I have boiled it twice (I think) The pedal went spongey and recoved with time mostly leaving a bit of spongyness. I have done it once on the road (After changing my hoses for braided and being an idiot) and once on my first (And only so far

) track outing. Last time I couldn't find any Castrol so plumbed for the generic Dot 4.

What is the difference btwn Dot 4, Super Dot 4 and Dot 5?

Also should I be looking at changing the EBC Greenstuff pad / OEM disk combo seing as I appear to have a heavy braking foot?

I have a bit of cash to spunk ATM......

mac · Post by **mac** » Sun Jul 02, 2006 8:19 pm

Rich,

Dot 5 is a mineral based fluid IIRC.

The difference between DOT4 and Super Dot4 is the dry and wet boiling points. (wet boiling point is the temp at which it boils when it absorbed water)

There is different dry & wet boiling points between different makes. Try
ATE super racing blue.

Mac

Rich H · Post by **Rich H** » Sun Jul 02, 2006 8:29 pm

OK will do, where can I get it?

I have heard that my brake pad combo runs hot at the best of times, but only anecdotally, anyone know for sure?

Cheer
Rich

Rich H · Post by **Rich H** » Sun Jul 02, 2006 8:58 pm

Found a stockist:

http://www.hispecmotorsport.co.uk/brake_fluid.htm

£18/litre+VAT

Anyone else want some?

Calipers look like they might fit too if anyone wants any:

http://www.hispecmotorsport.co.uk/ul2_-_radial.htm

tenkfeet · Post by **tenkfeet** » Sun Jul 02, 2006 9:20 pm

Interesting reading after a google search .

http://www.h-e-l.co.uk/HEL_Performance_ ... or_FAQ.htm

I don't think dot 5 is compatible with some seals . Don't know if its as bad as Skydrol(Phosphate ester ) in dtd 585 systems.

I personally have not had any problems using dot 4 on the track or on the road . The cost at £4 a litre means I can change it and bleed the system without mounting costs.

I changed my wooden OEM pads for SBS ones and they are much better, more feel and bite . They can feel a bit poor on first application when cold which clears after the first application.

Rich H · Post by **Rich H** » Sun Jul 02, 2006 9:33 pm

Been busy with google....

DOT 5 is the silicon based crap they put in citrons (AKA LMH ??) DOT 5.1 is OK, so the DOT number is faily irrelevant by the looks of things just the wet and dry boiling points (Higher the better)

So is it my crap braking procedure that s causing the problem? (Probably) I have also blued my disks on several occasions (ie badly overheated them) so I would like to think it was pad/disk combo (but it probably isn't

)

tenkfeet · Post by **tenkfeet** » Sun Jul 02, 2006 9:54 pm

Double post

mac · Post by **mac** » Sun Jul 02, 2006 10:21 pm

Rich,

Just going from experience there is a huge difference in superDOT 4 performance. Put some of the cheaper carplan stuff in both mine and Ironside's cars and we promptly changed it again after 1 outing on track!

Try Euro Carpark - pretty sure Simon (Ironside) go it for a tenner - but I could be wrong as he was buying bulk(ish)

Mac

Tom · Post by **Tom** » Mon Jul 03, 2006 9:50 am

Robin will know more, but i wouldn't use DOT 5. Incompatible w. any of the others so i wouldn't even drain and fill w. dot5.

dot 4 is hygroscopic(?) - absorbs moisture from atmosphere. dot 5 doesn't, so in theory better, but i'm sure i read somewhere (maybe service manual)that dot 5 shouldn't be used in an elise. there's graphs that show how much the boiling point is lowered by even the smallest exposure to humidity/air.. supposed to be changed every year (why isn't it part of an A service??)

Post by **ironside** » Mon Jul 03, 2006 10:19 am

RICHARDHUMBLE wrote:Found a stockist:

http://www.hispecmotorsport.co.uk/brake_fluid.htm

£18/litre+VAT

Be interested to hear if HiSpec actually reply on the brake fluid front. ATE TYP 200 and ATE Racing Blue (both on HiSpec's site) are exactly the same specification fluid except for the colour. The Racing Blue being blue coloured and the TYP 200 being normal brake fluid coloured.

The idea is that you switch fluids each change and you know when you've got all the fluid through when the stuff coming out changes colour:

Trouble is I can't find anywhere that will sell the TYP 200.

Eurocarparts will sell you ATE blue for much less though £10.45/litre+VAT (Part no: 130339010) but they can't get the TYP 200. If HiSpec do reply - I'd like some TYP 200 if you're organising a group buy.

Cheers,
Simon

Rich H · Post by **Rich H** » Mon Jul 03, 2006 10:26 am

I'll go to Eurocarparts then at that price. I haven't contacted Hi-spec yet. If those calipers fit then that could be a cheapo 4 pot conversion for some of you track whores....