Trident rear caliper

I posted a little while ago about the rear brake binding-up on my '93
Trident. I'd bought a new disk and pads in May last year (did consider a
new caliper but was quoted some ridiculous price) and had the caliper
cleaned up (and new seals fitted) by a competent motor-mechanic friend.
Two or three weeks ago after a 15 mile ride I found the rear disk was nearly
red hot and the caliper was cooking up nicely too, so obviously the pistons
were sticking. My mechanic mate recommends (as a first-aid thing) taking
the lid off the fluid reservoir and using a blunt flat object to apply
leverage to the piston-side pad so as to force the pistons back down into
the caliper barrels to free them up.

Does this seem a reasonable approach? I'm a bit puzzled by the problem
appearing so soon after last year's overhaul, that's all, though the bike
hasn't had an awful lot of use over the winter, and it's only done about
2,500 miles since the brake overhaul. Maybe I should have the caliper
overhauled again, or maybe bite the bullet and get a new caliper...

Any suggestions from m'learned friends?

BTW (TOG?) would I be likely to find spare calipers etc at Kempton Park?

 

Yes - make sure the sliding half of the caliper is moving freely. This
is a common problem on pre-99 Tigers. If some water's got into the
holes that the sliding pegs go into, a bit of surface rust can bind
things up, stopping the caliper halfs from moving apart when you
release the brake pressure.


--
Krusty
www.MuddyStuff.co.uk
Off-Road Classifieds

'02 MV Senna '03 Tiger 955i (for sale) '96 Tiger '79 Fantic Hiro 250

 

Thus spake Brian () unto the assembled multitudes:

Thanks guys (Brian and Krusty so far) for your thoughts. Will have
another go at freeing it up, but I suspect you are right about getting the
caliper rebuilt again. I'm seeing my mechanic mate again today so will
have a word.

 

Is there any free play at the master cylinder, or is the master cylinder
returning fully?

Oily

 

Thus spake Howard () unto the assembled multitudes:

Hmmm. Had a bit of a full-on weekend (start of the bowling season!) so
didn't get time to check these points. In any case the caliper's off now
and in the car waiting to be delivered to my mechanic mate. I'll check the
other two thingies when I get the caliper back. There definitely seems to
be a reluctance to move on the part of the pistons, though, even when
disconnected from the hydraulics.

Thanks again...

 

Thus spake Krusty () unto the assembled multitudes:

Just to mention that there is no "sliding half" on my Trident caliper; the
caliper is a single body and the only moving parts are the pistons and
pads, which themselves slide to and fro on pins mounted through the caliper
body.

 

Thus spake A.Lee (alan@darkroom.+.com) unto the assembled multitudes:

Thanks Alan, but my mechanic mate has all the right gear in his workshop to
get the pistons out. He managed OK last time, anyway.

 

A.Lee says...

I've got a little set up that allows me to pump pistons out on the
bench. I knocked it up using a ZX-7R rearset with an RF900 m/cylinder
coupled to a long brake hose.

--
Lozzo
Triumph Daytona 955i SE (Black with added black bits)
Suzuki GSX-R750L trackbike (Shite with added shite bits)
Yamaha SR250 Cheasy-Rider (undergoing a transformation)
I ride way too fast to worry about cholestorol.

 

Or consider stripping the master cylinder (which I may yet do on the
Tigger). Those Triumph calipers do tend to seize up somewhat though -
I bought some spare ones a little while back and had a fun day
stripping down ten (IIRC) calipers and rebuilding them. Does mean I've
got some ready-built ones to swap onto the Tigger as I need them
though.

 

The caliper itself slides on two pins on the mounting bracket. Those
can get rusty and seize up.

 

Thus spake Mike Fleming ({mike}@tauzero.co.uk) unto the assembled multitudes:

Mine doesn't. The caliper is bolted solidly to the mounting bracket.
There is no movement of the caliper at all. I guess later calipers are
designed as you describe. Mine is an early ('93) Trident, after all.

 

'93 isn't early for a Trident - this is:

http://www.apah69.dsl.pipex.com/mybikes/Triumph T150 Trident.jpg

 

Thus spake Keith G () unto the assembled multitudes:

*sigh*

Oright, an early *Hinckley* Trident. Happy?

 

No MP3, but here's a little movie for you (25 secs. @ 8 Mb):

http://www.apah69.dsl.pipex.com/show/Trident.AVI

It's very shrill (all tappets and pussy pipes) due to being made with
only an ordinary digital camera's video function, but it'll probably
find that filling for you!

 

Yesh.

(Dentures removed, as requested..)

 

Thus spake SpamTrapSeeSig () unto the assembled multitudes:

Sheesh, talk about a bag of spanners!

I'm sure it sounded nice going up the road though.

 

Don't blame the bike, the sound in *video mode* on the camera used
(Samsung) was absolutely hopeless - see this clip by way of
illustration:

http://www.apah69.dsl.pipex.com/show/Money.AVI

No bass at all - but the sound on that setup was really quite good!

I'm sure it would, if No.2 son had blown the damn thing up - head
gasket, I suspect.....

 

My two Tridents are early ones and the Tigger is 1996. They all have
the slidey 2-pot calipers. Daytona 900 and 1200 have 4-pot calipers
(same as off one model of GSXR750 IIRC) which bolt direct to the fork
slider.

 

I havr the kit for one of those...

 

??

What 'kit'..??