Triumph Rat Motorcycle Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Bike of the Month Challenge!

1 - 16 of 16 Posts

·
Registered
Joined
·
648 Posts
Discussion Starter · #1 ·
After a 6 month lay up my rear brakes on my 2003 T/Bird seem very poor, Siezed Piston? is this an easy fix?
 

·
Registered
Joined
·
84 Posts
seal kit

seal kit costs about £25 if I recall.
Fitting time, an hour or so.
the hard bit is getting the pistons out if they are really seized in well.
you can push them out part of the way using hydraulic pressure (pump the pedal with the caliper off the bike).
there are special piston pulling tools that can remove very tight pistons without marking them, you may not need such stuff but do not be tempted to pull a sticky piston out with a conventional pair of pliers, extreme expense awaits those who do this!
 

·
Registered
Joined
·
10 Posts
I've gotten stuck pistons out with compressed air. Use a nozzle with a rubber knob on it that will (kinda) seal against the threads of the fluid inlet. Blow the first piston out and then stick it back in the bore up to the seal and hold it so that the other piston will blow out. If they're REALLY locked up in there, try soaking from both sides in penetrating oil.
 

·
Registered
Joined
·
2,322 Posts
Be sure to have someone with a catcher's mitt ready when they blow! :D(Been there, done that) Great method, though, if you have access to compressed air.
 

·
Registered
Joined
·
10 Posts
Good looking out, guys. I forgot to mention that the pistons will take your noggin off if you're not careful while you blow on them. I like to blow them into a wadded up rag on the workbench. Also watch for aerosol-ed brake fluid and penetrating oil. Can't be good for you.
 

·
Registered
Joined
·
89 Posts
Don't get too fancy.

Compressed air may be the elegant, way to extract pistons, but there is a much safer, and easier way - albeit boring.

With the pads removed and the caliper halves separated, pump the pedal while carefully watching both pistons. Usually, even with proper function brakes, one piston will travel more than another. When you get to within 1/3" of the end of travel for the faster moving piston, wedge a screwdriver between the top of the "higher" piston, and the caliper extrusion. Pump the pedal again slowly with the screwdrier wedged so that the other piston starts to "catch up." When they are even with each other, remove the screwdriver and slowly pump again. Because friction can vary with piston travel, maybe the slower piston is now the faster piston. So, just use the screwdriver as a wedge so that both reach the top of travel within a few millimeters of each other.

One will pop out first, but if you've done it correctly, the other will be past the main seal and you can just wiggle it out, or worst case, wrap a thick shop towel around the piston and gently work it out with some channel locks. I've done this many times without an air compressor or holes in my fingers with great success.

I have yet to come across a piston that was seized so badly that I couldn't break it out with hydraulic pressure. But, I'm sure it must happen. Wedging one piston always does the trick.

Cheers
 

·
Registered
Joined
·
2,073 Posts
Rear brakes are single piston.
 

·
Premium Member
Joined
·
3,646 Posts

·
Registered
Joined
·
2,073 Posts
I just looked at bike bandit and they show a dual piston for my 99 Adventurer also.
The reality though is that while the caliper looks like a dual, only one cylinder is machined out of the casting.
The front is indeed a dual.
I just very recently did my brakes (front & rear) when I noticed this.
I thought it was a kinda cheezy way of building a single vs. dual piston setup.
It's as though B-Bandit missed the ball on this one.
 

·
Registered
Joined
·
2,073 Posts
I even looked up the specs for my bike and it said dual.
Imagine my surprise when I saw that one pot had not been machined for a cylinder/piston.
Externally it looks like a dual.
I may take a pic tomorrow and post it up.
I got nuthin' else to do thanks to gettin' laid off.
The same company has asked me back at a different location so it's all good.
But jeeez, haven't they ever heard of a transfer?
And actually it works out sweet since my severance will now be a bonus!!
I think I will pull that caliper tomorrow just to give us something to talk about.
 

·
Registered
Joined
·
89 Posts
Interesting, indeed. I assumed a dual piston setup per the diagrams (and my TBS), but a single is even easier to remove!

Usually BB diagrams are pretty accurate, though, I have found a few instances of incorrect diagrams. One example: BB has the diagrams for the handlebars swapped for the TBS and Thunderbird. The TBS have much "flatter" dimensions (less taper, less reach) than the T-Bird, but the diagrams indicate otherwise. I've notified them of the possible error. In the past they've been pretty good about fixing things (i.e. a 99 cent detent ball listed for $44!)
 

·
Premium Member
Joined
·
3,646 Posts
Hmmm, both my bikes have 2 pistons in the rear caliper.
My original rear caliper had 2 pistons too. I cant imagine that a single piston version as described would work very well

KD5QOQ - is the one piston in the middle of the pad? Kinda wondering if you have a one-off unfinished unit somehow (seems unlikely)
 

·
Premium Member
Joined
·
3,646 Posts

·
Registered
Joined
·
648 Posts
Discussion Starter · #16 ·
Sorted thanks, wasn't seized afterall? just changed the fluid and bled, not brilliant but better than the soles of my shoes.
 
1 - 16 of 16 Posts
Top