brake fluid for the NSR?

Tomnsrowner · Derestricted Danger Joined: 08 Dec 2003 Karma :

please help, my brakes are crap, i changed the pads and bled the system, and they were great , for a week or two lol. Now they seem to bite then go very weak , it doesn't get any better when they warm up a bit, if anything they seem better from cold, i changed the dot 4 fluid and the pads i put in were sintered ones (forgot the name), please help, shall i use dot5 instead?

mr jamez · World Chat Champion Joined: 04 Aug 2003 Karma :

I think if you put dot5 in when you were previously using dot4 it can rot the seals etc. I would flush it all out with brake fluid again and bleed the brakes. Perhaps give the calipers a clean out and check that they are working properley e.g. pistons pushing and returning smoothly. However I am not sure if this is normal for NSR brakes as I haven't had a chance to use them yet Smile

What pads did you get? as EBC are apparently the best (I think)

Smile

GFK · Scooby Slapper Joined: 03 Apr 2003 Karma :

You can also change the brake lines - standard NSR ones are just crappy rubber, which expands under pressure and you lose pressure at the wheel.

Get some braided stainless steel ones instead. They don't expand, so all the fluid pressure ends up in the right place.

G · The Voice of Reason Joined: 02 Feb 2002 Karma :

Make sure you get the best pads you can, this does seem to make quite a difference.
Personally I'd recommend Carbone Loraine SBK3 for bigger bikes, never tried them on smaller bikes. If not anything sintered is a good start. EBC HH are generally considered to be fairly good.

You do /not/ want DOT5, your brake fluid is not boiling (if it is, then be worried), so this will not offer you any advantage. DOT5 also absorbs water, so needs to be changed more regularly in theory, it also costs loads more.
As stated, DOT 4 and DOT 5 do not mix well, creating a corrosive compound I believe, so best to avoid.

A good clean of the pistons and calipers in general and some copper grease in appropriate places doesn't go amiss either Smile

.

Braided hoses are the next thing I'd go for after decent pads.
NSR brakes do seem to be quite variable, so don't expect too much though.

Scotty · Scooter Boi Joined: 31 Jul 2002 Karma :

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Rubber hoses in some ways are better than braided steel lines. The steel lines tend to give less feel I find. However rubber hoses to age and then they can get very spongy.

DOT 5 fluid does not absorb water at all. That is the problem with it. Normal DOT 3 or DOT 4 absorbs water like crazy, which means that any water in the system is absorbed by the fluid and flushed out when you bleed the brakes through (and this is why conventional brake fluids need to be bled through on a fairly regular basis). DOT 5 does not mix with the water, so the water tends to settle in areas of the system, boiling nicely when you brake and also causing corrosion.

Also many systems use seals that are not compatible with DOT 5 fluid.

Do not confuse DOT 5 with DOT 5.1. DOT 5.1 is a conventional fluid like DOT 3 or DOT 4. DOT 5 is silicon based.

Given the problems you are having I could firstly check that the pads are clean and that nothing has leaked onto them and contaminated them. After that I would rebleed the system with fresh fluid, and also check that the brake lines are in good condition.

I don't think that EBC do their HH pads for the NSR unfortunatly.

All the best

Keith
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Danny · Ask Me About Stoppie School Joined: 26 Jan 2003 Karma :

Hex · Party Boy Joined: 04 Feb 2002 Karma :

Tomnsrowner · Derestricted Danger Joined: 08 Dec 2003 Karma :

thanks guys , i'll bleed them this weekend and i'll let you know how i get on. would it be possible to fit the master cylinder and resovoir from an nsr 250, would this improve breaking? shall i just get the nsr 250 caliper ? or both lol. both are available at DK motorcycles (large dealer/breaker) they do all sorts there.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

It might help, it might really screw things up. You would need to check first (at least) the master cylinder bores.

Anyway, with D&K prices it would probably be cheaper to buy a radial Brembo master cylinder.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing