R12 fr/brakes on rear of R10

Damien Gardner

Well-known member
1000+ Posts
Joined
Jan 25, 2001
Messages
2,432
Location
Wendouree Vic. Aust
Any clues ? Can't get a good pedal on brakes, i've narrowed it down to L/H/R caliper, pinching off the hose gets rock hard pedal with about 20mm travel, un-pinch the hose gets half way to floor spongy as buggary pedal,
I put a new seal kit in to achieve the half way pedal.
Have pushed piston all the way in & clamped it, then bled it again, no air in oil! I placed steel blocks of equivalent thickness to pads & rotor re bled still the same result, I've bled the caliper from all different angles tapping it with a hammer to try to dislodge any air bubbles, still no joy have put 2L of oil thru it so far. Need some ideas PLEASE. :confused:

<small>[ 02 October 2002, 08:37 PM: Message edited by: Damien Gardner ]</small>
 
Damien, What condition is the hose in, are you sure the hose isn't ballooning.

Ren
cheers!
 
Damien,
I had a similar problem with my R8G. It was isolated to the LHF caliper. I can't remember the technical term, but it is to do with the seating of the 'O' ring.
I changed the caliper and it was fixed instantly.

Robert
 
Damien, any chance that the caliper has a fracture somewhere causing flex of the forks that hold the pad opposite the piston? This causes a soft pedal - you can even feel the difference between an aluminium caliper and a cast iron caliper of the same design because of flex. That's the only thing I can think of...

PS. I take it you're not really using oil! :D

Cheers

Stuey
 
Hi Stuey,
No Dot 4 high temp brake fluid actually,
Hadn't thought of a fracture possibility a club member has offered a caliper & will bring it to our meeting tomorrow night, so i'll fit it friday and see what happens. I had the same problems last year while trying to fit R16 rotor & calipers to the R10 front 2 worked fine i never got the back 2 to work, so i abandoned the project. I'll need to re-address the R16 situation for the front again soon to help bias the braking to the front in view of the rear end mods i've made.
 
After sitting over night the damn thing is as spongy as ever

<small>[ 14 September 2002, 05:07 PM: Message edited by: Damien Gardner ]</small>
 
Strange one this changing the pads cured the problem although only half worn my test with steel plates off the rotor only used the same thickness as the rotor and pads combined on advice from Dave C's Dad Ian i pushed the piston in and put steel between the piston & pad and voila' nice peddle, further testing explained the piston was jamming on the rubber dust boot hard enough that when the peddle was released the rubber had enough force to push the piston back hence extreme knock off. Glad it's over

dance dance
 
Top