TOPIC:

Maybe opening up a can of worms here, like asking the best oil, best battery, or best tires. Those can be personal but I feel MC honing should be answered by science. What is actually best to allow new seals to properly seat. Understanding that pits and corrosion are not removable or shouldn’t be removed with a hone due to the chances of increasing bore to much. Let start the debate with that as a given.

I don’t know if the MC’s on the kz have inserts or some how they change the hardness of the aluminum at the bore, so that the first question. Second, to many moons ago when we would rebuild wheel cylinders we always ran a hone thru them... my whole career I have been told to hone master cylinders and wheel cylinders to break the glaze to give the new parts a nice surface to seat into. Similar with honing engine cylinders.

That being said I’ve read here that some recommend honing, where others say no... the MC’s we have are the same vintage as when we were taught to hone. What has or did change that some here are saying not to hone?

I ask because I have a front that I want to rebuild for my KZ900 project. Aslo in full disclosure I have rebuilt 3 MC’s. Not one has leaked or lost pressure from sitting... On all of them I have run the matching size ball hone in them and I’ve used 320 grit hone with brake fluid as a lubricant.

What say you?

I would only hone them if they looked pitted. And as you point out...deep pitting would only be removed by boring them, which would necessitate a sleeve. I'm sure I know people who have done it but none are coming to mind.

If you need to keep it stock I understand but I went with one of these , it works great and looks stock
www.z1enterprises.com/fr-double-disk-m-c...sembly-kawasaki.html

bluej58 wrote: If you need to keep it stock I understand but I went with one of these , it works great and looks stock
www.z1enterprises.com/fr-double-disk-m-c...sembly-kawasaki.html

Thank you, I’m staying with the KHI master I already have, 5/8 bore and the piston seal kit...

hardrockminer wrote: I would only hone them if they looked pitted. And as you point out...deep pitting would only be removed by boring them, which would necessitate a sleeve. I'm sure I know people who have done it but none are coming to mind.

The one I have is not pitted. The bore is shiny like a mirror... would you hone very lightly on a slow speed just to rough up a little?

If you buy a new master the bore will be shinny and smooth so I don't see any value in honing.

Nessism wrote: If you buy a new master the bore will be shinny and smooth so I don't see any value in honing.

That I didn’t know. Then I’d have to agree.

No, I would not rough it up. I would try it first and if it leaks I would try a hone with the expectation that the next step would be to drill it oversize and install a sleeve.

It's not like a cylinder where you need to expend a lot of effort to undo things if you make a boo boo.

hardrockminer wrote: No, I would not rough it up. I would try it first and if it leaks I would try a hone with the expectation that the next step would be to drill it oversize and install a sleeve.

It's not like a cylinder where you need to expend a lot of effort to undo things if you make a boo boo.

Thank you... I’m going to assembly it as soon as the long reach internal snap ring pliers arrive... I agree if it leaks not a big deal to redo!

No eBay APP ID and/or Cert ID defined in Kunena configurationI wouldn't use a ball hone for that.
Steve

I kind of hone mine when I rebuild a MC, but its more like polishing. I wrap a piece of 400 grit paper around a wood dowel or roll up a scotch brite pad to the correct diameter and polish in a honing like pattern.
I understand honing in a piston cylinder. Metal cylinder seating metal rings. But a master cylinder is metal against rubber seals. I believe as smooth and shiny as possible is best.

If there's no pitting we don't touch 'em. If very minor, shallow pitting, a very brief session with a ball hone to knock sharp edges off the pits.

Good Ridin'
slmjim & Z1BEBE