Triumphrat

gregp · 11-13-2007

The front caliper on my 96 Adventurer is dragging heavily. It drags significantly more when pushing the bike backwards than it does when pushing it forward. A month or so ago I cleaned and lubed the caliper pins and pushed the pistons out as far as I dared and cleaned all around them with a brass brush and brake cleaner. This seemed to help a bit, but the caliper quickly returned to dragging heavily. So, I guess that I will have to pull the pistons completely out to clean them up better and clean up the bores.
I have never rebuilt a bike caliper before. Can I just pull the caliper pistons out (with lots of pressure), or do I have to push them out with fluid or air? Are there any tricks to help with disassembly/reassembly?
I have also read here that some Kawasaki Nissin piston seals fit. Can anybody tell me an exact Kawasaki model to cross reference?

du_ratai · 11-13-2007

click here maybe it helps:
http://www.dp-brakes.com/dp.php?load...ch&csearch=117
some (dp117 pads) bikes should use same calipers, if you understand what i mean.
somewhere on web i already saw how was solved same problem. can't find right now.

jimmyj900 · 11-13-2007

Your brake drag may be related to disc and pad wear -- if the extension of the pistons is too great then they'll tend to go off angle and drag in the bores.

Jim

gregp · 11-14-2007

Excellent point, Jimmy. I have new pads on the way, so I will install those and see if the problem disappears. If not, I will tear the caliper down. Thanks!

gregp · 11-19-2007

Well, the old pads were not worn very much at all, so I had to pop the pucks out. I wish somebody had told me that they pop out of their bores much like a 12 guage deer slug. My finger only bled for a few minutes (28 F out), but it hurt for hours. I popped the first one out with about 50 PSI of air. I cleaned up the seals, puck, and bore, then replaced it. I had to clamp it into place to get the other side to pop out with 100 PSI. Both bores were clean and the pucks were nice and shiney. The outer dust seals were starting to deteriorate, but I just cleaned them up as best I could and replaced them. The inner seals were fine, but I removed both of them and reversed them (flopped them over). Problem solved.
Next spring I will get a rebuild kit and do it right, but for now I am good to go.

du_ratai · 11-20-2007

last year i broke caliper bracket (went away with disc lock), had 1 week to fix before travel. then i was looking for caliper or bracket and somewhere on web found that not only Triumph use nissin calipers. and there was story about caliper piston bad work or something like. so that man used early honda cbr600 caliper kit (reason for it was cheaper or triumph didn't supply?)
few days ago i replaced brake pads, beside found crack on 1 disc and that damaged caliper doesn't perform well, pads on it about half worn than on oposit side. possible slide bar is bent. Go for used honda caliper or do full brake upgrade? beringer full set...

gregp · 11-20-2007

When your pads are worn significantly more on one side of the caliper, that usually suggests that the pins are siezed up, and the caliper can not self-center easily.
Thank you for the CBR cross referencing tips, though!

du_ratai · 11-21-2007

Quote:

Originally Posted by gregp

When your pads are worn significantly more on one side of the caliper, that usually suggests that the pins are siezed up, and the caliper can not self-center easily.
Thank you for the CBR cross referencing tips, though!

oops, i forgot to mention, i ride TBS, so pads of damaged caliper (rhs) were worn less than pads of oposit caliper (lhs). and this is more noticeable than differece between pads of every single caliper.

greyplague · 04-04-2008

[quote=gregp;873716]
I have never rebuilt a bike caliper before. Can I just pull the caliper pistons out (with lots of pressure), or do I have to push them out with fluid or air? Are there any tricks to help with disassembly/reassembly?
quote]

Have a look at dansmc-http://www.dansmc.com/hydraulics.htm
Nice site!
Thieu