The Stovebolt Site Forums The Shop Area General Truck Talk how do you keep your stones clean on M/C rebuild

honing out a OLD master cyl and the stones keep getting gunked up. i hate to just keep replacing them. they get a layer of oil like gunk on them and i can tell they aren't doing right. i usually put a tad of brake fluid in to use as fluid but i've never had it do this before. does anyone out there have a way to clean them without messing them up and keeping them flat. thanks, hr

I use a coffee can of kerosene that I dip the hone into real often and a catch pan under the backing plate if on the vehicle. If its getting packed up then your letting the hone dry out, keep the stones wet, a light fluid like kerosene will keep the stones washed out. If I have the wheel or master cylinder off the vehicle I submerge the cylinder in kerosene completely while honing it. Your solvent tank works great to do this in also, just submerge the cylinder in the fluid and hone away. Make sure you are constantly working the hone back and forth to keep the wear even on the stones and the bore round and not tapered.
DG

As I'm honeing I rinse the hone in solvent and have been using the same stones for years. No brake fluid or oil.

OOps, it looks like Denny was posting as I was typing.
Cleon

I've used brake fluid, freely, without any difficulty. It keeps the stones from clogging, and you can clean it with either alcohol or water. I wouldn't use any petroleum-based solvent for honing brake cylinders because of the trouble with cleaning the petroleum oil out of the system. The stones will wear out eventually, but they will last for quite a few cylinders using brake fluid as the lubricant. You could use water if you want to, but use a lot of it, and wash the cylinder with brake fluid when you are finished. You can't use water if your stones have been wetted with petroleum oil.

Harvester

at my former job working at an aerospace comapny, we would hone very hard materials like chrome carbide and tungsten carbide, and from time to time i would take the honing stones and give them a light grit blast, with say 100 grit aluminum oxide grit.

leonard

I'm with Harvester. I use brake fluid as a honing oil/solvent. Works great and you don't have to worry about contamination from the solvent migrating into the brakes.

I use brake fluid, too.

I like to use dot 3 for honing than flush out with brake clean and round brush, blow dry with compressed air and reassemble with clean dot 3.

I use brake cleaner on brake parts when honing, no petroleum.
Scott

I understand his problem as I have, for whatever reason, ended up with stones that get a little clogged. So, as a do it yourself guy I sometimes LIGHTLY touch them to the wire brush on my bench grinder. This isn't often but it will work if you have to.

thanks for all the advice. this master cyl was in pretty bad shape. it had to get a slide hammer to remove the piston- that i cut threads into. i had to do this 3 times as the piston came out in 3 pieces. so that was how old it was and bad it was. it has sat unused for a long time. i guess i had not ran into this before. i tried touching them up on the wire wheel but i didn't like how it did. i always use brake fluid to hone before and it wasn't this bad. i finally got it done and it's all back together. hopefully i will get it back on this weekend. thanks again, hr

Just clean the cylinders well before you reassemble the system. Don't read more into the cautions about petroleum products and brake systems than is really there. The intent is not to mix petroleum fluids and brake-fluid. Light petroleum fluids like kerosene have been used as a cleaning fluid for honing operations since time began. If you insist on believing that the part has to be "surgically clean" before brake fluid touches it, then just swab it out with some soap and water and rinse it clear or wash it with lacquer thinner or brake cleaner or what ever. Also contrary to popular belief metal, cast iron included is not porous and will not soak up and retain fluids like a sponge. The important thing is to make sure you wipe it good and dry and that it's clean before reassembly.
Remember, common sense is not so common!
Denny Graham
Sandwich, IL