[tmoons]

hi, does anyone here know a cheap place to get the caliper pistons from?
They seem to have the 30.2X29(ish) measurments, but i'm having a hard time locating them for a reasanble price (150 euro for 4 little metal cups is a bit steep...)

OR... does anyone know about calipers with different sized cups, that fit the ZR fork (55mm c-c distance), and which are perhaps cheaper to maintain.

(i did read all the Zr7(e) conversions, but i'm not ready to go all that far..

 

[zr7_interloper]

I think your cheapest option is to check out some of the zr-7's contemporaries.
For example, SV-650s calipers look the same. And used ones are quite cheap on ebay.
You'll probably have to take the measurements of the calipers to to be sure.

 

[tmoons]

@ ZR7 interloper: you mean looking at complete calipers? At first i want to see if i can get some fairpriced pistons...

 

[Wado750]

Are your pistons that bad, that they need replacement? Use some steel wool to clean off the corrosion, if that's the problem.

 

[tmoons]

After some more checking and fiddling I think I had some air behind 1 piston. this gave:
seepage past this piston and it gave a sponge feel in the lever. I have now cleared the air. The lever is firm and predicable (it was not, as it was soft at the first pull and harder at the second...). I got the air out AT the piston, I turned it around (spinning it in the cylinder with some pliers taking care not to bend or damage them). this allowed for the air (and a tiny little fluid) to escape and presto all done.

to bad, I now bought a ZX6r front end (callipers and forks.. )

 

[zr7_interloper]

After some more checking and fiddling I think I had some air behind 1 piston. this gave:
seepage past this piston and it gave a sponge feel in the lever. I have now cleared the air. The lever is firm and predicable (it was not, as it was soft at the first pull and harder at the second...). I got the air out AT the piston, I turned it around (spinning it in the cylinder with some pliers taking care not to bend or damage them). this allowed for the air (and a tiny little fluid) to escape and presto all done.

to bad, I now bought a ZX6r front end (callipers and forks.. )

So, there was a "stubborn" air bubble at the piston that could not be cleared by normal brake bleeding? Very interesting....
Thanks for sharing your technique for getting rid of it.

 

[tmoons]

I have no proof this was an actual bubble. but:
- I bled the MC (pumping till pressure, undoing the banjo bolt, repeat a few times)
- I bled the junction at the bottom of the tree (like the MC)
- I bled the callipers (like the MC)
but still no cigar.
Off we went tying the mc lever to the handle bars at super human squeeze forces...
This gave some seepage at both callipers but still no hard lever, but after the rotation trick, no more seepage, and a rock hard handle.

my guess:
Air is much thinner than the fluid, and is able to utilize the micro scratches in the piston to "escape" and as there are bigger and larger scratches the rotation helped to find the bigger ones, as the air passed, it allowed for a little fluid to "tag along".
and now all is fluid and presto... no leak, no sponge.

 

[TWOQUIDKEV]

hi, does anyone here know a cheap place to get the caliper pistons from?
They seem to have the 30.2X29(ish) measurments, but i'm having a hard time locating them for a reasanble price (150 euro for 4 little metal cups is a bit steep...)

OR... does anyone know about calipers with different sized cups, that fit the ZR fork (55mm c-c distance), and which are perhaps cheaper to maintain.

(i did read all the Zr7(e) conversions, but i'm not ready to go all that far..

Just found this place looks quite cheap, depends on delivery to europe £6-£30. drop them an email and enquire before ordering.

Caliper Piston Kawasaki ZR-7 1999-04 - Motorcycle Parts From Motorcycle Products Ltd Online Motorbike Spares Shop

£68.36 for 4 pistons and seals is a steal, you'd have to steal them to get them any cheaper lol

£68.36 = 86 euros = $108

 

[tmoons]

That is about the same price i had to pay, my problem being that i just bought new seals and caliper overhaul kits (16 euro's each, needed two) so that would compound on the price....
i mean, we are only talking a bout a small bush, 30 mm wide, 29 high, that is used in a wide range of bikes... (SV650, ZR's and a number of others).

I have now solved the issue by spending 160 euros on a complete tree of a Zx6R (1995) with calipers and upgraded springs.