Front brake caliper alternative 2WK 88' (currrent parts obsolete))
 

I have come across a problem with trying to rebuild my XT600's front brakes, namely the caliper and piston. The piston for the caliper is scored and requires replacement, however, the piston and seal kit I need (1990 Yamaha RT180A Front Brake Caliper | Yamaha Sports Plaza) is no longer available (only new old stock but I haven't found any yet). The seal kit alone is available, but without a good piston I cannot use the caliper at this stage. If I am unable to find a second hand piston from a wrecker I will need something else.

Has anyone had the same problem and found an alternative caliper to use perhaps?

I am having difficulty in determining if a caliper is suitable as the dimensions of the parts aren't available, thus there's nothing to refer too.

I have been searching the internet for possible workarounds but have had no real luck in determining a solution.

I am in Australia, therefore, the bike doesn't appear to have the same forks or brakes as those on the American models (evident on Partzilla and purchasing the wrong seals).

1988 XT600W
Eng no. 2WK

hi have you tried ,https://www.kedo.de/ ,or ebay ,161566376052,they may do others if this one isnt right ,you might have to measure your piston ,steve

try bikebrakes-uk on ebay

Another option; have the piston hard chromed or make a new one.

p

Many thanks for the replies. I will keep searching for some new old stock or the rear caliper to fit onto the front. In the meantime I will investigate chroming as you suggest or even filling in the score with solder and smoothing it back to see if I can get away with it.

For the long term future of the bike I will probably investigate the dimensions of the 1990's XT's front shocks and look at fabricating a spacer to mount the twin piston calipers of the 90's models, or if possible buying a second hand fork setup.

People put stainless sleeves in the calipers when corrosion gets to them. You may be able to resleeve the calipers to some standard size and use 'standard' pistons and seals... I can still get parts for a 1980 brembo front caliper. The difference between what you have and the new size should be small so as not to effect ratios too much. Try to stick with a brand like Nissian, Brembo and you may be better off parts wise.
How is the master cylinder?

cutting some aluminum plate and making an adapter for a more modern caliper is no biggie. to make sure you get this right, do first one in plywood to see how it all lines up before cutting metal.
most likely you will need some turned spacer to center caliper on disc

my supermoto thread should have pics of the caliper plate i made

no i see there's no pic...

That's interesting Warin to resleeve the caliper but certainly an option. The caliper is a Nissin one and the master cylinder is in perfect order with new seals too. It's just the caliper that's the problem.

That's a nice mount turboguzzi, exactly what I was thinking about doing to accommodate the twin piston caliper off the 90's XT. At least with the 90's caliper the seals and piston kits are readily available and even OEM calipers too. This is most likely upgrade I'll do which will see the bike for another 20 odd years.