Source for a Rear MC Kit for MNS - 11/16

[CatatonicBug]

I am in a pickle. I am trying to rebuild the rear MC on my bike, and no one seems to carry the 11/16 kit for the linked brakes of the MNS. Apparently, the OEM part number is 4W1-W0042-00-00, but I can't seem to find anyone who sells them. I know the XJ has a similar system, but I can't find anyone who can verify the compatibility of parts. Can anyone out there point me in the right direction?

[DGXSER]

No expert for sure, but on the parts fiche the LH and the XJ rear master cyl kits list as different part numbers. 4W1-W0042-00 for LH and 10MW004200 for the XJ.

[CatatonicBug]

If nothing else, the shaft and spring and stuff are all usable on the kit I have. What I really need are the 2 rubber parts. If there is another kit for a similar 11/16 bore MC, perhaps I can just use those pieces, and re-use the non-rubber parts that I have. One part looks like a flat-bottomed cup with a bump in the center (cups onto the spring), and the other is the center ring, just like all the other MC kits, but for the larger bore. Any ideas?

[Rasputin]

Check out
http://cgi.ebay.com/ebaymotors/XV535...mZ350176429377
I know its not the right one, but you could ask him about the rear. I know he does not list all his parts. He is really fast and good to deal with. JAT

[CatatonicBug]

I sent a message to Georgefix, so maybe he'll come up with something. However, I think I need someone who really knows these Master Cylinders inside and out, over the course of a few years and models. According to the local stealer and a local junkyard/parts depot, the part number I am looking for is no longer available. The K&L catalog shows a blank line for the Rear MC kit for the LH. So, What I need to find out is whether the kits from any other models (i.e. '82 XJ1100) would fit. I really only need the rubber parts, so as long as those match, I'm good. Can anybody help me on this?

[John]

You won't be able to find one from an XJ11 either. Though the P/N for the kits may differ, I'd be willing to bet they are the same kit, both made of unobtainium. Is there any way the cups and seals from a kit designed for a front M/C be used in a rear M/C?

[bikerphil]

Try the parts guy on the XJ site. He lists P/N HCP 2970 for an 82 XJ1100 rear master rebuild kit that he sells (or he used to).

[bikerphil]

Kinda hard to find the link....

HCP2970 OEM rear MASTER CYLINDER REBUILD KIT for all XJ1100 models.
$ 52.00

HCP7577 OEM rear master cylinder rubber PLUNGER BOOT, for all XJ1100 models.
$ 10.50

HCP3023 OEM rear master cylinder float O-RING, for all XJ1100 models.
$ 4.50

HCP4257 OEM rear master cylinder float CIRCLIP, for all XJ1100 models.
$ 1.50

http://xjbikes.com/Forums/viewtopic/.../start=30.html

[Schmeerman]

I have ordered from Chacal, from the XJ site, many times. His inventory is geared to XJ models, but he is very knowledgible and helpful. You may have to research, but I believe that the 81XS and the 82XJ are very similar, partswise. I am presently awaiting some valve shims for my 1100. He even carries aftermarket parts that work. If anyone can help you, he will. He answers all inquierys quickly, and is trustworthy. I would highly recommend contacting him.

[CatatonicBug]

Not sure what XJ site you guys are referring to, as this is the only cycle site I visit. However, I just talked to a mechanic friend of mine today, and he gave me an idea. The wheel cylinder of many cars has the same (11/16") bore, and also have a similar cupped rubber piece in them, like this '68 VW kit. He's gonna bring me a handful of possible replacement pieces tomorrow.

[DGXSER]

Hey CatatonicBug,

Phil had posted a link to the XJ site I think, it worked for me anyway. If your buddy has some parts that fit, that is even better in my view! Good luck!!

[CatatonicBug]

Ok, turns out the XJ runs a 3/4" MC, so it won't work in my 11/16" bore. Plus, all the seals I've tried from cars are just a little too thick, and actually plug the vent holes in the MC bore. So, my next thought is to try completely swapping out my MC for an XJ one. I figure that going from 11/16" to 3/4" won't be a bad thing, and as long as the bolt holes match, It should work just fine. Plus, rebuild kits for the XJ MC are still available (pricey, but available).

Wish me luck!

[CatatonicBug]

Well, I took my whole MC to the local bike graveyard, in the hopes of locating the XJ master cylinder. The guy took my MC to the back to show it to "the boss" and came back and told me that he located a source for a rebuild kit. I asked him if he was sure it was for the 11/16" bore, and he seemed pretty sure of himself. I am cautiously optimistic about it. I did see a full XJ for sale there in the lobby for $1200, and verified that the MC on it would definitley work for my bike. So, just in case the kit they ordered is not right, I know where to go next. I hate waiting....

[randy]

Couldn't you change the rear MC to the one from the 81SH, it didn't have linked brakes and the rebuild kit is about $30.

[CatatonicBug]

Couldn't you change the rear MC to the one from the 81SH, it didn't have linked brakes and the rebuild kit is about $30.

That's the problem - It didn't have linked brakes. Mine does, and I want to keep it that way. If I was to change it, I would have to get a new front MC as well, then get all new brake lines. The XJ has linked brakes, but the bore is 3/4" instead of the 11/16" on my MNS.