Replacement Master Cylinder

[Eastcoaster]

I am looking to replace a master cylinder just want to make sure I am going in the right direction. Would this be correct? Or any suggestions?

Thanks

https://www.mikesxs.net/product/08-0251.html

[DiverRay]

What bike? One or two front disks? Stainless brake lines? We need more information to help you with your choice.

[Eastcoaster]

79 xs1100 special. standard rubber brake lines good condition. MC has been a problem sticks leaks on and on I wanted to start out New

[mack]

Front m/c

https://www.mikesxs.net/product/08-0265.html
This is the one I typically use on my SF and LH

[jwhughes3]

https://www.mikesxs.net/product/08-0265.html
This is the one I typically use on my SF and LH

I have used same one successfully, but only with stainless braided lines. I think with rubber lines, the smaller stroke volume may not be sufficient with line stretch.

John

[Eastcoaster]

Macks selection

Anyone used this on this with this one and standard hose lines?

Thanks

[mack]

M/c

John, Could be right. I change all my lines to SS at the time of resto, but it does have a larger bore size.

[Blank Slate]

**************

Is there any bleeding required if I am replacing the front master cylinder with a new one? Or is it simply remove old one, connect new one, and fill up new one with dot3 fluid?

Re the green and brown wires. How does disconnecting / connecting them work? I did unscrew the headlight to be able to see everything. I just dont want to damage anything.

Fyi I'm working on my xs650se here. But I figure it's the same basic info. I bought the mikesxs front master cylinder 13mm to upgrade my bike's ugly old one.

[dbeardslee]

Any time you open up the brake system you're going to need to bleed it. You let air into the system and you have to get that air out for it to work properly. Another tip I've found helpful is after you bleed the system. Tie the front brake handle back and let it sit overnight like that. It will allow any small air bubbles that remain in the lines to bubble to the top.

[Blank Slate]

Thank you for that dbeard

[dbeardslee]

I'll add this too - when you bleed the system you generally have to pump the master cylinder a bit for the fluid to flow. But don't pull back too far on the handle. On XS11 master cylinders you can unseat the plunger if you pull back too far on the handle when there's no pressure on it, and then you wind up having to take the master cylinder apart to put the plunger back in place. A block of wood tied between the handlebar and the brake lever will keep you from pulling it back too far, and might save you some trouble. You just need to pull the handle back far enough for the fluid to flow. Not sure if you'll experience the same issue with an aftermarket master cylinder, but it's usually better to be safe than sorry.

Also, a power bleeder makes things go a lot easier. It can be a real PITA to bleed a brake system without one.

[CaptonZap]

You might also want to be sure that every portion of the brake line between the caliper and the master cylinder slopes up, so the bubbles can migrate up to the master cylinder. If you bled it while on the center stand, you might want to put it on the side stand and turn the front wheel to the left. Look at all the line, and make sure there is no droop less than level anywhere in the run.

CZ

[Bigrod024]

I ended up going on ePay and buying a used Nissin MC from a honda vfr700. It'd have to be from a vfr700 not a 750 as they changed the bore size from 5/8(vfr700) to 1/2(vfr750). I was kinda skeptical buying a brandless MC not knowing what parts availability would be like in years to come, and also not sure of quality control and the validity of the expressed warranty. Got mine in good working order for <$70 shipped. Now I have a Nissin and not a ?????.

[MPittma100]

Master Cylinder

I am looking to replace a master cylinder just want to make sure I am going in the right direction. Would this be correct? Or any suggestions?

Thanks

https://www.mikesxs.net/product/08-0251.html

I would suggest that you purchase a rebuild kit for your current m/c. Not that hard to rebuild it. Will save $ over a new unit and no mods necessary.

[dbeardslee]

I would suggest that you purchase a rebuild kit for your current m/c. Not that hard to rebuild it. Will save $ over a new unit and no mods necessary.

That sounds like a real good idea. The one thing you may run into a problem with is the brake light switch if you change to a different MC. And there's not really much inside one - basically a tube and some holes and a plunger assembly. The plunger is the mainest part, and you get a new one in the rebuild kits.

Tools are pretty basic - couple wrenches and some snap ring pliers. A round wire brush works well for cleaning out the bore, but anything you can get down in there and scrub with will work.