Brake Fluid

[ferg]

Currently fixing up the brakes on the XT. I managed to boil the fluid going over the Bealach na Ba last year (there's a story there) and would rather it didn't happen again

The thing is that that sort of braking is quite rare, most corners you have to speed up for on the old girl. What fluid should I be using to cover both situations? Will the 'race' stuff or higher spec, 5.1 etc, be rubbish with normal riding? Will I almost ride off a cliff again by using normal stuff?

Thoughts, opinions and hot drink preferences?

[kaighn80]

coffee white one sugar and no you should be fine with 5.1 its more to do with its boiling point being higher than it having a higher overall working temp, its not like carbon disks where they have to get up to temp before they start to work

[gsxr renegade]

I’ve always wondered about brake fluid – do the higher ratings have any adverse effects on performance. I mean – if 5.1 has a higher boiling point than standard stuff but doesn’t have any downsides – why don’t manufacturers just use 5.1 as standard? Does it need replacing more often or something?

Oh, and I'm in an Earl Grey mood today.

[ferg]

I’ve always wondered about brake fluid – do the higher ratings have any adverse effects on performance. I mean – if 5.1 has a higher boiling point than standard stuff but doesn’t have any downsides – why don’t manufacturers just use 5.1 as standard? Does it need replacing more often or something?

Oh, and I'm in an Earl Grey mood today.

That was my wonderment exactly.

Kettle's on I fancy a Lady Grey at the moment.... or perhaps some Darjeeling.

[lorenzo]

I've been using Motul RBF dot 4 recently and it's an improvement over the boggo motul 5.1 in terms of where it starts to get all boily. If you're really posh you can go for castrol stuff that's about 9 times the price and boild at a heady 4 degrees higher or something! I did a bit of googling and found a few sites where they list boiling points. There's no downside to having better brake fluid, it's just that it costs more, hence you get average fluid in there as stock, the same as shock absorbers all have cheapo oil in there and OEM tyres are never espcially nice.

[thefatman]

To balance things out you can spend more on brake fluid but after doing quite a few trackdays on Comma dot 4 brake fluid which is £2 a bottle i've never once had a problem with it.

Keep your brakes clean and check its not binding as this makes it overheat more readily.

[hipringle]

To balance things out you can spend more on brake fluid but after doing quite a few trackdays on Comma dot 4 brake fluid which is £2 a bottle i've never once had a problem with it.

Keep your brakes clean and check its not binding as this makes it overheat more readily.

Nice one Tim but do your brakes actually work mate?

[ferg]

Thank Hugh. He was ace help, the rest of you well...

Interesting stuff though. The brakes normally run drag free but then that doesn't mean they are perfect. Should give them a clean too while I'm changing the lines over.

I couldn't find any 'propa' thick soup so went for some of the Motul stuff Lorenzo was on about, not sure if there'll be enough left over for lunch afterwards though.

I never thought of the weather conditions having an effect when you're topping them up! Although waiting for a warm and dry day in Caithness may have me old and grey before the job gets jobbed! Interesting stuff though.

Cheers muchly gents.... take that how you will

[lorenzo]

Once you've done them you'll have half a bottle left over; Wop some cling film over the to before you put the lid on, to keep it fresh. Or give it to Hipringle and tell him it's apple juice...