Front master cyl. rebuild kit

[72XS2]

Hi, I ordered a master cylinder rebuild kit from 650central. Michael contact me to suggest me to change the master cylinder for a new one. I want to keep my bike stock so I wonder if anyone already use this kit to rebuild a master cylinder. If so, does it work good ?

Thanks

 

[BigBoreSwede]

Hi

Hard to say.....it depends.

If it´s only comes down to the seals and gaskets a kit should work fine but if the piston is worn it´s most likley you´ll need another/new master cylinder.

I got a kit once for my Suzuki GS 1100 e but it never really worked that well. A far as I understand the master cylinder is very sensitive to wear and if your master cylinder is about 30-35 years old maybe it´s time to get rid of it.

BUT.........I would try one of these kits first before throwing the cylinder in the garbage can. You´re never sure until you try

/BigBoreSwede

 

[72XS2]

That's what I'll do. I already dismount it and the piston looks fine. The bike have only 27000 miles on it, I assume that there's not too much wear in it. I'll tell you what happen with it.

 

[xjwmx]

Hi
if the piston is worn it´s most likley you´ll need another/new master cylinder.

The mc kit usually includes a new piston. There's no reason to change your mc unless it's pitted or otherwise messed up. I used Mikes kit on my mc ('81) and it was great. Use the opportunity of having it apart to brake cleaner the hell out of it. Don't hone it just as a matter of course, because it's aluminum. I didn't touch mine with anything abrasive. Use brake fluid as assembly lube for the seals.

 

[Stigda]

Hi there.
Does anybody know where i can find a mastercylinder repkit for 1975 single disc? Tried Rudiger, my lokal Yamaha-dealer and Mikes webshop?
Showing my mc and two different pistons. The left one is the original from my bike, and the right one is a repkit that seems to be for a later model (77?)

 

[72XS2]

Hi there.
Does anybody know where i can find a mastercylinder repkit for 1975 single disc?

You can find it at 650central.com. I bought one kit for my 72 front master cyl. and it works great. The piston is not exactly like the one in your master cylinder but it fits there and work good.

 

[Stigda]

You can find it at 650central.com. I bought one kit for my 72 front master cyl. and it works great. The piston is not exactly like the one in your master cylinder but it fits there and work good.

Thank you 72XS2, found it at 650central, hopefully it fits my -75 as well.

About the caliper on this bike; why does the Clymer manual tell us to get new bridge bolts and hex bolts when the caliper has been opened?

 

[XSLeo]

I think all the early models have the same bore size. The M/C is marked 5/8. I think thats 5/8 inch which is 16 mm.
In 77 when they changed calipers they went to a 14 mm M/C.
Stigda, in your pic you show two pistons. What are the diameters of the pistons? If the one on the left came out of your 75 it should be 16 mm.
The right one looks much bigger. It maybe a 22 mm piston. If it is that fits the early dual disc set up found on the European bikes. They used a 22 mm M/C with the two piston calipers used on the early dual disc brakes.