OF SOUTH AUSTRALIA INC |
How not to do it by Jim Leach |
OF SOUTH AUSTRALIA INC |
From: | Tigerootes (at) aol.com |
Sent: | Sunday, July 05, 2009 12:10 PM |
To: | HillmanCars@yahoogroups.com |
Subject: | Re: [HillmanCars] Master Cylinder Question |
Over the years I have rebuilt hundreds of master cylinders and many years ago, I wondered why my rebuilds (cast iron cylinders) failed after about three years of service – almost like clockwork! At the time I was using a spring-loaded 3- (flat) stone honer, tiny but very similar to what a machine shop would use on an engine block during a proper rebuild.
Anyway, I dropped the darned thing on the floor and broke one stone, so as a replacement I purchased a carbide 'ball' honer and not one rebuild since then has failed.
The answer: flat honing stones cause the drilled ports in the bores to become VERY sharp and the cup/s take damage every time they pass over those ports. By using ball hones, those passages are automatically chamfered.
I bought a full set of ball hones ... very costly (even back then) but well worth it.
Jim
HOME page