Modern rear master

[Ctopher87]

I was just wondering if anyone has swapped a modern rear master on the rear. I've rebuilt the original and changed fluid tanks due to the original cracked and leaking. Now the newer tank has began to leak also. If anyone has done this could you please enlighten me as to what mc was used and the alterations to make it work. I could put another used tank however I would expect the same results from 30+ year old plastic.

[soccer4m]

Me also

Howdy, I also have use someday for another rear master, but most folks here just keep rebuilding them as they are pretty simple devices. I have seen members do all kinds of mods on the front master and brakes, but nothing for the rear yet. It probably has to do with the brake pedal alignment with the master cylinder. There are lots avail. on site and ebay,,,,and rebuild kits. Since the travel is so short from the master to the caliper, not much is needed,,,anyway I guess no one has a mod............someday....Mike in Sun Diego

[bikerphil]

I am sure something would work with a custom fabricated adapter plate. The mounting bolts on other units are probably not going to line up with the XS frame. Have to be careful of the new improved braking, don't want too much power going to the rear, locking up the tire is not good. 1/2" bore is the size IIRC.

[FJ111200]

Yep, I'm using a XJR1200 rear m/c made by Brembo.
I've taken some pictures on my phone but can't get them to load up to my computer, but will post asap.
Basically only one mounting bolt can be used and where the other should be I've lashed a couple of cable ties through the hole and round the downtube of the frame. The reservoir sits behind the side panel and is also lashed up.
It looks a bit rat bike-ish but works better than what I had and i'm going to look for a standard XS replacement, maybe .
It's a 14mm bore working on the Midnight Special rear caliper with a braided hose. I had a look-see with an FJ1200 m/c, which is similar, but looked a bit harder to set up.

[FJ111200]

Can't edit my previous post as too late but should also have said that the XJR m/c clears the swing arm by 1 - 2 mm, so it is a bit close but doesn't touch.

[Ctopher87]

I appriciate the input. It may take a while to get it finished bit I'll post up when I do. I've got a lot going on right now considering my truck decided to spin a bearing but I'll get to it soon.

[FJ111200]

Bit crappy but there you go.
And reservoir behind side panel.

[bikerphil]

I like that mod, I am going to try something similar very soon.

[FJ111200]

I like that mod, I am going to try something similar very soon.

Thanks. I'd like to see what you do to give me a better idea.
Also I said previously that the XJR m/c is a 14mm, well I was wrong, I've just looked again and it's a ½" just like the original.

[Ctopher87]

It looks like I can make that work. Might see about fab bing up a tab and use two bolts in it. I've been working on a smaller battery box and customach side covers. I should be able to mount the reservoir to the new box and still keep it clean. I'll update as I progress however it may be a while. I need my truck for work to pay for all these ventures with the xs. Once it's on the road again I can get back to work on this beast.

[Andy_WI]

I was working on a different bike and I did pretty much the same thing - custom bracket (minor welding) and some rear master cylinder. I had to extend the hose for better reservoir mounting location. It was several years ago and unfortunately I don't have any pictures but it looks very similar to FJ111200's setup.

Please excuse me posting into this thread but I'd like to ask soccer4m if I should just search forum for the front master upgrades. I'm planning to get brand new unit off eBay and ss lines for the front.

[TomB]

I did it with a bit of welding

[TopCatGr58]

Please excuse me posting into this thread but I'd like to ask soccer4m if I should just search forum for the front master upgrades. I'm planning to get brand new unit off eBay and ss lines for the front.

Hey Andy,

The thing to remember is that the front MC has to drive 2 calipers, and so it's suggested to get one with a 16mm bore to provide the capacity to pump the volume of fluid required. Also, you have a Special, but not sure if you still have OEM buckhorns, or have changed to others that are not as extremely bent/angled. The Special MC is slanted to compensate for the buckhorns position/angle, but may not be needed with other flatter bars.

As for eBay, not sure of what you'll find. Both MikesXS.net and Partsnmore.com sell replacement front MC's at decent prices and they will stand behind their product.

T.C.

[bikerphil]

Andy, I have this nice Brembo/Ducati front MC on my Special, its a high quality unit, powder coat finish inside and out, definite nice upgrade. There is an optional bracket for a LH thread mirror mount.

http://www.ebay.com/itm/Ducati-OEM-B...3D332155097145

[TomB]

Hey Andy,

The thing to remember is that the front MC has to drive 2 calipers, and so it's suggested to get one with a 16mm bore to provide the capacity to pump the volume of fluid required. T.C.

The size of M/C depends on which calipers you have, and even then a 14mm will work well with the Standard (big) calipers, I have a 14mm M/C and Standard calipers, it makes for much more force applied to the pads with the same amount of hand pressure, with the trade off of having much more lever travel. A much better front brake.