Master Cylinder

[Dennis N.]

I was referred to this site because I need my 67 BB master brake cylinder rebuilt.
It seems there was a discussion regarding the brass vs stainless steel insert advantages/disadvantages.
If anyone can reference this dsicussion for me, please let me know.
Thanks
Dennis#41743

[Mike M.]

Re: Master Cylinder

stainless sleeves essentially non-porous whereas the bronze inserts , being porous, have greater weep potential. i use stainless steel brakes in clarence NY.their phone # is 716 759 8666. good luck, mike

[Dennis N.]

Re: Master Cylinder

Wow, 3 whole minutes from the time of the post til I got a reply! Thanks for the info, Mike, ss made logical sense to me, but a discussion at the Corvette Action Center suggested I check it out here.
Now if I could only do something abiut the time they have listed a s the post time...it was 10:01 when I posted, not 7:01..can't imagine me getting up that early to post messages, lol. Thanks again.
Dennis#41743

[Scott Marzahl]

Re: Master Cylinder

You can do a search of the archives, there was lots of discussion on this topic. I used Apple Hydraulics and they highly recommended using the brass liner for drivers and SS for garage queens, I went with the brass. Geat job and good turnaround. The cost difference between the two wasn't much either.

[John H.]

Re: Master Cylinder

I've used White Post for many cars over many years - they use brass sleeves (not bronze), which are not porous; Apple Hydraulics also uses brass. I'm sure either SS or brass will outlast any of us.

[Joe L.]

Re: Master Cylinder

Dennis-----

For master cylinders I prefer brass. I feel that it has better wear and seal preservation properties for a hydraulic cylinder (master cylinder pistons have significant travel in the bore compared to constant-contact type, Corvette caliper pistons which move an infinitesimal amount in their bores upon brake application). However, as John mentioned, for all practical purposes, there is probably little difference between stainless and brass sleeving for master cylinders.

[John H.]

Re: Master Cylinder

I prefer the brass process for other reasons - the SS sleeve process machines the bore, then presses in a stainless steel sleeve; the pressing process can introduce "waves", if you will (although very small) in the longitudinal wall of the sleeve.

The brass process machines the bore, presses in a brass sleeve, then the I.D. of the brass sleeve is machined again to create a perfectly round and longitudinally flat surface for the seals to ride on.

[Joe L.]

Re: Master Cylinder

John-----

Yes, that's an excellent point that I hadn't really thought about too much. As you say, the brass sleeves are machined to final bore size after installation and the stainless sleeves are pre-bored to bore size before installation. I can well see how what you described could occur even if a mandrel was used when the sleeve was installed; these are LONG sleeves and must be a "tight" interference fit. For an item like a master cylinder in which a precision bore size is absolutely critical to performance, there would be nothing like honing to size AFTER installation of the sleeve to produce a perfect bore. So, I just became convinced more than ever that a brass sleeve is the only way to go.

[Mike M.]

Re: Master Cylinder

joe, john, et al: it was my understanding when talking with the guys in clarence NY in the mid 70's( when they did my 1st midyear caliper set) that they press a piece of ss bar stock then bore it to riginal dimensions. perhaps they've changed their proceedure. anyway, the ole 65 FI roadster hasn'st leaked a cc since i installed the ss sleeved calipers(i also opted for their ss pistons at the time) mike