Help needed - Master-cylinder rubber seal

I need some help (sorry for long story but I want to give all the details as I'm kind of sure someone already got this problem).

Currently restoring a 1983 1000 J3 and I need to replace the rubber seal of front brake master cylinder piston (located just behind the brake lever). Pretty simple you told me: "Just look at Partzilla, and accordingly to picture #1, simply order part 49016 (complete p/n 49016-1041) and it's done." That's what I did but: "Wrong".

The seal is too large; as shown on picture #2, its diameter is 23 mm while I need a part of about ~18.2 mm diam. To fit in the master-cylinder. Picture #3 also shows that piston diameter is 14 mm.

Looking back at the part diagrams (I looked at J1/J2, J3, R1, R2 B1, B2 '82 spectre and even 1000 Police), I found another strange thing. All of those bikes have a plastic clip (item 14008) and some kind of washer, round or slotted (item 43022) (ref: pictures #4 & #5).

But if you look again at picture #2, you'll see that my master-cylinder do not have those two items; instead, there is a circlip. And the master-cylinder really looks to be OEM!

Another one: item 49016 on picture #5 (Spectre), is identical to what I ordered style-wise and different than what is illustrated on 1000J3's picture #1. But both bikes call for the part I ordered (49016-1041).

So, my question is simple: What seal p/n I need to order to repair my master-cylinder?

Hope someone here can help me.
Many thanks for your time guys!!

[img] live.staticflickr.com/65535/51890339484_70e0caa2ba_c.jpg[/img ]

[img] live.staticflickr.com/65535/51890094108_0ae8817b78_c.jpg[/img ]

[img] live.staticflickr.com/65535/51890658525_621bf8a756_c.jpg[/img ]

[img] live.staticflickr.com/65535/51890658520_f1c24b6a1f_z.jpg[/img ]

[img] live.staticflickr.com/65535/51890658510_51b1f13ced_z.jpg[/img ]

kzrider.com/forum/5-chassis/609792-gpz-master-cylinder#842704

The EX500, and other smaller bikes, use a 14mm master cylinder and have the circlip and boot like yours. 

www.partzilla.com/catalog/kawasaki/motor...ront-master-cylinder
 

wrote:

The EX500, and other smaller bikes, use a 14mm master cylinder and have the circlip and boot like yours. 

www.partzilla.com/catalog/kawasaki/motor...ront-master-cylinder

 

Great find for me!! Many thanks!! Then I suppose my master-cylinder is not J3 OEM. This bike I bought was a non completed project from the previous owner and I think he maybe never rode with this master-cylinder on this J3.
What's the typical piston diameter for a KZ1000?
Here's another picture showing more views of my part.

wrote:

The EX500, and other smaller bikes, use a 14mm master cylinder and have the circlip and boot like yours. 

www.partzilla.com/catalog/kawasaki/motor...ront-master-cylinder

 

Texas, do you know if this Ninja 500 use single or twin front brakes?
Wondering if using this 14 mm MC on my J3 is a good idea. I don't think so but what do you think?
Thanks again!

Claude how does it compare with the  2 x 82's that you have. I can't imagine it changed much from the J2 to the J3 ?

wrote:

Claude how does it compare with the  2 x 82's that you have. I can't imagine it changed much from the J2 to the J3 ?

Good idea! Did not think about this... One is already in part boxes so I should be able to compare them quite easily. Will do this early next week as the week-end is for my lovely pillion... )
But if a 14 mm diameter piston is recommended only for a single disc setup, I, for sure, will not use it on 1000J.
*******************************
EDIT
On ebay, rebuild kits for J3 are different than for J1/J2. I ignore the difference(s) but there is at least one.

wrote:

wrote:

The EX500, and other smaller bikes, use a 14mm master cylinder and have the circlip and boot like yours. 

www.partzilla.com/catalog/kawasaki/motor...ront-master-cylinder


 

Texas, do you know if this Ninja 500 use single or twin front brakes?
Wondering if using this 14 mm MC on my J3 is a good idea. I don't think so but what do you think?
Thanks again!

The 500 has a single disc, but it should be ok to use it on your J3. I have one ready to install on my ZRX, which has two six-piston calipers up front. It is a pretty common upgrade for the ZRX.

Texas, it is an upgrade for ZRX? How can this be working? I’m a newbie for this but I thought that a smaller diameter piston (assuming J’s larger than 14 mm diam.) would allow yes, more pressure, but at the cost of a way too long stoke... Do you know the reason it works??

That is right. A tiny bit of extra travel for one finger stoppies.

Hi Claude, you are right in so much as the 14mm is 25% smaller than a 19mm so would need to travel 25% further to displace the same amount of fluid. However I suspect the pivot position of the lever has been moved to change the lever ratio. This would give more piston travel for the same amount of hand lever travel (would just need to pull a bit harder)

Did the J3 come with a 19mm master? If so, a 14 may be a pretty large jump. The ZRX came with a 5/8 inch (15.87mm) from the factory.