Yamaha TRX850 Enthusiasts Forum

I was playing around with my Rex over the Christmas break,you know washing, polishing,riding when I thought the brakes are feeling a bit wooden i'll change the brake fluid.I think Mr Yamaha recomends changing it at 42000K's and mine was done then as part of a dealer service.The bike has done 20000k's since then.I could not believe the thick crap that came out of the system.My Rex runs standard brakes because at the speeds I do I've never felt the need to change them for blue spots etc.but with the new fluid I nearly put myself over the handlebars with the first application,the difference was amazing.

the thick crap you describe is the inside of the rubber hose breaking down ,, it really is time to change the brake lines , and its probably cheaper to fit braided stainless steel hoses ,,

I changed mine for dot 5 - the silicone (?) based fluid last year... It should be compatible with dot 4 mineral fluid, but I've ended up with what looks like condensation forming on the rubber tube from the reservoir to the MC, but is actually brake fluid 'breathing' through the rubber ! I used high pressure fuel line which should be resistant to virtually any hydro-carbon fluid, but this dot 5 seems to be able to get through it...
It's not a huge worry at the moment, but I'll be flushing it out before the summer and refilling with dot 4...

Greg

Greg wrote:I changed mine for dot 5 - the silicone (?) based fluid last year... It should be compatible with dot 4 mineral fluid, but I've ended up with what looks like condensation forming on the rubber tube from the reservoir to the MC, but is actually brake fluid 'breathing' through the rubber ! I used high pressure fuel line which should be resistant to virtually any hydro-carbon fluid, but this dot 5 seems to be able to get through it...
It's not a huge worry at the moment, but I'll be flushing it out before the summer and refilling with dot 4...

Greg

My dot4 is going thru the "breakfluid spec" i´ve bought from 2 companies now but has now got a tip of a company wich are specialists on hoses so i will check them up and try again....

DOT 5 fluid is incompatible with DOT 3 and 4 fluids and shouldn't be used in a system that has ever contained them. It's also more hygroscopic than DOT 3 and 4 so needs to be changed more often. DOT 5.1 is compatible with 3 and 4 though.

Aaaargh ...

Just checked my bottle - Halfrauds 5.1 .... phew, but it still doesn't explain my seepage lol..

Greg

could well be condensation ,,perhaps try a master cylinder seal kit ?

Noooo ... it's definitely brake fluid. Certainly made me

Greg

Thanks Steve for the heads-up,I'll certainly look at new lines in the near future.
An interesting byline to this story is that when I was finishing up changing the brakefluid my missus came home and made the comment that she wishes I spoiled her as much as I do the TRX(I wonder what colour the sky is in her world).

rocket60 wrote:Thanks Steve for the heads-up,I'll certainly look at new lines in the near future.
An interesting byline to this story is that when I was finishing up changing the brakefluid my missus came home and made the comment that she wishes I spoiled her as much as I do the TRX(I wonder what colour the sky is in her world).

Don't fill your wife with brake fluid. They will put you in jail for a very long time!

rocket60 wrote: my missus came home and made the comment that she wishes I spoiled her as much as I do the TRX(I wonder what colour the sky is in her world).

Not that old chestnut !
Mine made me howl one day by saying she wished she had wheels & an engine so I would be as interested in her as I am my cars & bikes !