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Brake fluid questions...

Posted: Tue Feb 14, 2012 9:20 pm
by Rasta-ninja
Hey all, my brake pads are pretty worn down so im going to be getting round to changing them fairly soon so i thought i may as well bleed the brakes. Just a couple of questions first. I know the manual says DOT 3 but i was told that it would be ok to mix DOT 4 with it, is this correct? Also any recommendations on which brake fluid to use?
Considering buying a speed bleeder nipple as well....anyone actually got one of these?
All help and advice appreciated!

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 12:03 am
by damienbish
If your gonna bleed the brakes and top up etc I'd personally not mix different grades and just do a complete change. Its not exactly loads of fluid and if it hasn't been changed in a while its certainly advisable. Ive also got one of the quick bleed kits, cost about a fiver on ebay its basically just two tubes connected to a one way valve in the middle. Ive found it really handy as and have been able to bleed the brakes on my own as with the one way valve its not possible to suck air back into the brakes.

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 12:08 am
by cargo
damienbish wrote:If your gonna bleed the brakes and top up etc I'd personally not mix different grades and just do a complete change. Its not exactly loads of fluid and if it hasn't been changed in a while its certainly advisable. Ive also got one of the quick bleed kits, cost about a fiver on ebay its basically just two tubes connected to a one way valve in the middle. Ive found it really handy as and have been able to bleed the brakes on my own as with the one way valve its not possible to suck air back into the brakes.

How do you do a "complete change" of brake fluid ?

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 12:50 am
by Rasta-ninja
ok i can see your logic, but say i bought some DOT 3, the likelihood of it being the same as what's already in their is unlikely(don't know what the previous owner used). The fact its not the same brand shouldn't matter should it? Plus they'd probably be the same colour so i wouldn't be able to tell when its the new fluid is through, and i don't wana drain the whole system cos then im starting from ground zero

And what i meant by the speed bleeder nipple(I've only just found out about these things today) is that if your doing a one man job, instead of constantly having to open and close the nipple and pulling the leaver whilst topping up the reservoir! these"speed bleeders" have some sort of valve system inside so you dont have to keep opening and closing the nipple. You simply just pull on the brake handle and when you do the fluid gets sucked out, then when you release the handle the valves inside it close stopping air getting into the system. Pretty cool idea to be honest but they are about £8 a piece i think, and i'd rather save £24 just for the sake of being lazy :lol:

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 2:18 am
by damienbish

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 1:04 pm
by Rasta-ninja
no no lol, http://www.ebay.co.uk/itm/Goodridge-Spe ... 194wt_1344 that is what i was talking about. Its a nipple you leave in, but when it comes to bleeding you loosen it slightly and do the procedure i talked about before. As for fluid any recommendations? Obviously you have branded names that are ridiculously priced but i know that brakes are what keep you alive so was just wondering what people thought/recommend, silkolene seems to be the cheapest branded name i can find

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 1:22 pm
by cargo
I've never need any kind of gadget to help with brake bleeding or changing fluid.

bit of plastic pipe and a bottle................works everytime for me

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 2:09 pm
by damienbish
I see what you mean, never used one myself.

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 5:41 pm
by Rasta-ninja
I'm having a little trouble getting my calliper mounting bolts off.... is this because i need to have the bike on a paddock stand? or are the bolts just being a bitch?

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 6:37 pm
by RedexRobB
sounds like they are being a bitch, a stand has nothing to do with it. I guess they are pretty tight and havent been undone in quite a few years.

Make sure you have the right size socket/spanner as if they are tight and you have the wrong size it may round the head off. If need be, get an extension bar to give you the leverage but really, they shouldnt be that tight to need it. If they do then they have been overtightened.

Re: Brake fluid questions...

Posted: Wed Feb 15, 2012 7:31 pm
by Rasta-ninja
dammmn, i thought this was the case. The sprockets are definately the right fit, 12mm i was using. I tried using an extension as well, sounded like it was destroying my ratchet cos it would just kind've give under the pressure i was applying, and click the wrong way, if that makes any sense. Im pretty reluctant to spray wd40 or anything like that around my brakes as well but may have to

Re: Brake fluid questions...

Posted: Fri Feb 17, 2012 8:24 pm
by RedexRobB
You shouldnt really use a ratchet to undo really, its not what they are made for. A solid 'breaker' bar should be used. Shouldnt need wd either.

Re: Brake fluid questions...

Posted: Sat Feb 18, 2012 1:13 am
by Rasta-ninja
yeah eventually managed to get the buggers off after just trying to turn em for ageeeeeees. Settled for some castrol motorcycle brake fluid, a litre for a tenner. In the end didn't bother changing pads cos theres plenty of life left in the ones that had already been on there, plus i know for a fact the calliper assembly bolts are even more challenging to get off!

Re: Brake fluid questions...

Posted: Sat Feb 18, 2012 5:11 am
by cargo
Pray tell what have the caliper "assembly bolts" got to do with changing the brake pads ?

Re: Brake fluid questions...

Posted: Sat Feb 18, 2012 12:30 pm
by Rasta-ninja
nothing it would seem :lol: didn't realise that all you had to do to get them off on this bike was remove pad spring/pin and clip. I helped changed pads on my friends car and we had to actually take the calliper apart first, thought it might of been the same principle here