Dot5.1 Fluid Upgrade

[rjben]

Can anybody suggest a suitable brake fluid upgrade foe my Elise? I’ve been advised to use PRF600:

http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?CLS=ROAD&TLGRP=R004&PGRP=RP042&GRP=RP042&PCODE=A/PCP4510

but have no experience of it. Will it be OK in an Elise? Any precautions around mixing with 5.1 etc?

Cheers,

Rob

[Matt_C]

Lotus state that only DOT 4 should be used.

[havoc]

Super DOT-4 has the same limits as 5.1. I used that last time and it's been more than adequate...not an Elise, but it really doesn't make any odds.

As I understand, DOT4, Super-DOT4, and DOT5.1 are all interchangeable, without flushing the system or any hassle like that. DOT5 is the odd-one-out, and should be avoided.

[adrianr]

What's wrong with the standard stuff?

AdrianR

[Buster44]

If you do trackdays Castrol SRF is the stuff worth going for. Priced at circa £40 per litre, but a good investment if you currently suffer from brake fade.

[adrianr]

If your brake fade is due to a problem with the fluid, then your pedal will go straight to the floor* and you _will_ know about it. I've never heard of this happening on the Elise (S1 Esprits on the other hand...).

Unless you've had this happen, or your brake fluid comes out black when you bleed the brakes I would say the standard stuff is fine, just make sure you change it every 1-2 years with fresh from a sealed bottle.

AdrianR

* because the fluid, or more likely the moisture it has absorbed has boiled and the bubbles are spongey.

[rjben]

Thanks Gents,

I've made a mistake RE assumptions made about existing fluid. I thought it was Dot5.1 but it turns out to be DOT4, so I'll be using 5.1 in future.

As for the problem that led to this question: Well I did not experience boiled water vapour in fluid (soft pedal) or pads operating outside of temp range (hard pedal, no brakes), what I experienced was a spongy horrible unresponsive pedal that still provided the ultimate breaking force but felt damped on initial operation. I thought I had braided hoses but it now appears not to be the case......so I think braided hoses should solve my problem.

Cheers,

Rob

[havoc]

rjben said:

...what I experienced was a spongy horrible unresponsive pedal that still provided the ultimate braking force but felt damped on initial operation.

Ahhh...I've found your problem...you're driving a Ford!!!

[rjben]

Cheeky!

[GreenV8S]

In my experience, when pads overheat they feel spongey before they really fade. I think it's because you have to push harder on the pedal to get the same braking effect, you don't notice the extra effort in the heat of the moment just that the pedal is moving further than normal.

[rjben]

I really don't think I'm pushing my car as hard as you though!

Cheers,

Rob