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Help Needed on Master Cylinder Choice

  • Thread starter Thread starter Suzuki_Don
  • Start date Start date
S

Suzuki_Don

Guest
I need to purchase a front master cylinder for my 550 which has twin rotors, I have come across this new item on EBAY Item No. 120694922080.

It says in the description it suits a double caliper brake system, but it also says it is 14mm piston & bore. The usual standard for twin rotors is to use the 5/8" (16mm) bore master cylinder.

Could someone that is in the know have a look at the item and give me some advice on whether it will work on my bike or not. Presently I have a single rotor master cylinder on my 550 which is I believe 14mm and is a bit spongy. Will this master cyl be any better, it's a good price and new, but wasted money if there is no improvement.

Thanks for any help given.
 
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Don,
A 14mm bore master on a dual disc GS will have a more spongy lever feel than a 5/8" master. Simple physics. The larger master will take more hand effort though so there are trade offs involved.
 
Don
I have the master cylinder from the same Kawasaki calipers that you have. When I get back home, I will check to see if the size is listed on them and report back.

I haven't had a chance to run bike yet so I can't say how they feel. I assume the master cylinder will work okay with these calipers. If I get off my rear and get some lines made/purchased and it stops snowing here, I will be able to give a better account.
 
16mm is the ticket.

That Bandit master doesn't have a mirror lug. Some of the GS masters have the threaded lug on the removable bar clamp piece so you could possibly use your old clamp (assuming the lug is built in) along with the newer master.

Partsnmore.com has some masters for reasonable prices. Check in the Yamaha section.
 
Nessism said:
That Bandit master doesn't have a mirror lug. Some of the GS masters have the threaded lug on the removable bar clamp piece so you could possibly use your old clamp (assuming the lug is built in) along with the newer master.
Click to expand...

Then I accidentally posted an S master...the naked ones have the mirror lug. So do SV1000 masters. First-gen Hayabusa masters do as well...I ran those on everything for a long time. Now I run radial Yamaha masters when I can and I have a clamp that dedicated mirror lug.
 
Thanks for the replies

Thanks for the replies

Thanks for the replies. It has been a challenge for me to find a 16mm master with the mirror mount, a lot of the masters suggested by different members on this post are fine but do not have the mirror mount. I have noticed though that the later model Suzukis particularly have that half clamp with a threaded section on top for the mirror to screw in as suggested by some on here.

Personally I would like to keep the bike original with the 16mm master with the round screw-on cap from about '78 to '79. But these seem as rare as hen's teeth. Failing that I would like to buy a brand new master so I know it will work perfectly without the need to be rebuilt. I rebuilt the 14mm stock master that is on my bike now, but i think the fluid is leaking past the piston, seals, etc.

The other night I thought the system had air in it so I bled both calipers. No air bubbles evidenced themselves. So I pulled the brake lever in and cable tied it to the handle bar. The following morning the lever was loose inside the cable tie and after removing it I pumped up the lever three or four times and I then got the pressure back in the front master.

So I am thinking the bore of the master might be worn and fluid is passing past the seals. The piston and seals are new factory parts so I know it's not that. Having said all this the front master has never caused a problem with loss of pressure when riding the bike on the road. It pulls up fine just feels spongy and the single rotor with the same caliper (only a single though) on my VX has a much better and firm feel to it.

Any other opinions greatly appreciated, or even if anyone has a master cylinder they would like to sell me or if anyone can point me to a master cylinder on Ebay that they come across that would be appreciated as well. There is a brand new GS1200 master cylinder here in OZ for sale for $150 but it is minus the brake lever which would cost me another $100 or more new from Suzuki here in OZ, it is a Nissin Master. Maybe I should just bite the bullet and pay up or maybe search the bike wrecking yards over here.
 
Don,

I have one of those master cylinder clamps with the mirror lug built in if you want it. Could measure the center to center hole distance if interested so you can figure out if it will match some other master.
 
Nessism said:
Don,

I have one of those master cylinder clamps with the mirror lug built in if you want it. Could measure the center to center hole distance if interested so you can figure out if it will match some other master.
Click to expand...

Thanks Ed for the offer. I will keep it in mind. I have just purchased off EBAY a master off an '88 ZX10 which should be 16mm as it has twin rotors. But it has the rectangle lid that screws down with phillips screws. I have asked Tarbash to look through his stuff to see if he has an original round lid master that is the 5/8" one. I plan to put the ZX10 master on when it arrives but would change over to the round lid type if I can find one eventually. Will probably need to make up new brake lines as the ones on the bike now are just long enough and might not reach the new master sufficiently. But that's no problem.

Thanks again Ed.
 
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This is the ZX10 Kawasaki master cykinder that I purchased off EBAY. It should work OK. Guess I should rebuild it with new seals at least before I install it.


Zx10b.jpg



88 KAWASAKI ZX10 FRONT BRAKE MASTER CYLINDER



.
 
It would appear that the 5/8 type round screw-on cap master cylinders are hard to come by so I was just wondering: !!!!!!!!!!!!!!!!!!!

Would it be possible to have my 14mm master bored out to 5/8" and fit the rebuild kit for the larger master cylinder with piston, seals, etc. or would the stroke be different.

Thanks.
 
I've Finally Installed the XZ10 Master Cylinder

I've Finally Installed the XZ10 Master Cylinder

I have just fitted the Kawasaki ZX10 (1988) 5/8" master cylinder to my bike. I rebuilt it with new piston, rubber seals, etc. It pretty much bolted straight on and the two S/S braided lines reached without any problems. I had to buy a double banjo bolt to fit the two fittings to the master cylinder, but be warned if you are fitting a Kawasaki master cylinder the banjo bolts are 10mm x 1.25mm and not 10mm x 1mm pitch as the Suzuki banjos are. The master cylinder also had a threaded portion for the mirror and the original Suzuki mirror screwed straight in to place.

I took the bike for a 160 mile trip yesterday and the front brakes are such an improvement and having the four different settings for the lever adjustment made a real difference as well.

Following are some pics of the fitment:

P1020644.jpg



P1020636.jpg



P1020655.jpg



P1020669.jpg



P1020673.jpg



.
 
Nice score Don.

I ended up getting a brand new MC from Mikes XS in the US, bit under $110 shipped.

Haven't had the opportunity to test it yet though of course, sort of need a running bike to do that :rolleyes:
 
Different Brake Switch

Different Brake Switch

Pete, Another benefit of this master cylinder is the different brake light switch that it uses. It's a micro switch and has a very positive action, not at all like the original switch on the GS bikes.

A few pics:

P1020621.jpg


P1020623.jpg



I know there is a small screw missing which holds it in place, this pic was taken before the installation was complete.
 
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