Triumphrat

Sport · 11-28-2006, 07:11 PM

Greetings,

I've been correcting excessive front brake lever travel by compressing the caliper pistons and then pumping until firm. This has worked great since I bought the bike new in 2002. Now it seems my M/C is "grabbing".

What I mean is that as I progressively squeeze the front brake the lever will stop momentarily then, as I continue to add pressure to the lever, jump and move frely again, only to grab again, and so on and so forth until I come to a stop. The bike responds by a fork dive each time the M/C allows the piston to move freely. I'd say the M/C "sticks" about 5 times as the lever is squeezed.

When I got home with the bike stopped I excercised the lever. Now I can hear the M/C piston "break free" from what it was grabbing to (maybe the cylinder walls). It sounds and feels like an unlubricated piston moving through the cylinder. Instead of traveling freely, it binds, or grabs until the lever force overcomes the grab.

~Is anybody familiar with this symptom?
~Could a rebuild kit remedy this issue; anybody know of a kit number (1999-2004 Sprint ST)?
~How about an aftermarket M/C? Somebody here installed a ZX Front brake system. Does anyone know the years and size ZX Kawi would fit on the ST?

Thanks for your suggestions.

Jhumphrey · 12-03-2006, 04:47 AM

I would guess your problem is at the pistons not the master cylinder. Do you clean all crud from around the piston, lubricate the piston, before compressing the piston back into the brake body? Have you replaced your brake fluid on a regular schedule?

BazzaST · 01-05-2007, 04:01 AM

Sport its a common ***** on the Sprint forum, cleaning the pistons with brake or using rubber grease on the caliper pistons work or do this -

On my 05 Sprint fitted six piston Tokico calipers, 5/8'' master cylinder, a bolt on fit.

Caliper and master cylinder can found on ZX series Kawasakis, GSXR Suzukis pre radial calipers, Hayabusa.

A lot of guys in the US are getting off ebay quite cheap, also the Triumph brake hoses fit.

I fitted two single lines which came with the brake bits, simpler and easier than the cross over line.

The calipers and master cylinder came from ZXR9 Kawasaki.

Barry