C-3 Master Brake Cylinder

[Bill Lloyd #33481]

I have searched the archive for the correct master cylinder casting number. Now that I know that it is 509 DC for my std brake '72, where is a good place to start to look for a restored piece or a core.

Bill

[Patrick H.]

Re: C-3 Master Brake Cylinder

Bill,

I picked two up from my local auto parts store. Sure, the date may not be correct, but the stamping for that can be very hard to read anyway. Otherwise it's right on.

Some people don't trust the quality of the rebuilds you buy, and I understand that. If they will let you look at the castings they have and you can find a date you like, you win the prize. You can then send it out if you wish.

Patrick

[George D.]

Re: C-3 Master Brake Cylinder

Try Lonestar Caliper (http://www.lonestarcaliper.com). They aren't cheap but the have the correct MC Assy and they are stainless steel sleeved. I purchased one from them and it is a nice piece.

Regards,

George

[Todd H 26112]

Resleave MC or no? Was: C-3 Master BC

Years of British car ownership instilled a willingness in me to rebuild hydraulics as needed.... However years ago I learned not to bother rebuilding calipers on C3s - just trade them in on ss resleaved jobs.

I have an old junker swap meet special C3 MC that needs to be brought back to life - does the same logic apply here? Is it std practice to also resleave these or can a standard rebuild maybe w/ a hone job and of course new seals and such work just fine? Afterall we are now somewhat out of the 'uniqueness' of C2/3 calipers and into pretty standard territory for Chevrolet products.

If not - any recommendations on folks to send it in to that can resleave a customers specific unit and return it? (may be a good idea to prep and paint before sending in - sure wouldn't want to media blast after rebuild if that is to be a necessary step)

[Jack H.]

Re: Resleave MC or no? Was: C-3 Master BC

Whether or not MC sleeving is needed is a judgement call made by the rebuilder based on visual inspection. If the bore is true and NOT pitted, sleeves aren't required. On older parts that have been sitting open to the air or ones that were 'mistreated' by not having brake fluid changed regularly (moisture absorbed into the fluid), its almost always the requirement to sleeve the bore.

Many prefer SS sleeves, since they resist wear, but this is almost always a proceedure that raises cost and delays turnaround. Vendors like Lonestar Caliper, mentioned in a prior post, use traditional brass sleeves and install SS sleeves as an option when the customer demands/requests.

In my opinion, the extra $$$ spent for SS sleeves is a waste. These classic cars just aren't driven that much to need SS. The original cast iron lasted 20-40 years and you can expect a similar robust life from a traditional brass sleeve....

[John H.]

Re: Resleave MC or no? Was: C-3 Master BC

Stainless sleeving is popular for the high-volume caliper/MC rebuilders, as they just clean up the bore and press in a seamless SS sleeve, then drill the holes thru the compensating ports. Brass sleeving is more costly, as the bore is machined, the brass sleeve is pressed in, and is then machined/precision-reamed to the finished I.D. spec - no longitudinal "waviness" in the finished bore wall surface with a brass sleeve. The other long-term advantage, of course, is that there is no ferrous content in a brass sleeve.

[Joe L.]

Re: Resleave MC or no? Was: C-3 Master BC

Todd-----

You are correct in your assessment of 65-82 Corvette calipers----rare is it that they are rebuildable without sleeving.

For master cylinders it's a little different, but not much. For some reason. corrosion doesn't affect master cylinder bores quite as often as it does calipers. Sometimes, you'll find a master cylinder that has a serviceable bore---not real often, but sometimes.

One thing, though: in my opinion, a SERVICEABLE master cylinder bore means that it can be rebuilt without honing. Honing of master cylinder bores, as is usually performed by commercial rebuilders, is the "death" of master cylinders. Master cylinders just don't usually perform well after a "hone job"; they just can't hold the pressure required. As far as I know, all of the master cylinder kits on the market, including those used by commercial rebuilders, are designed for standard bore master cylinders. After honing, a master cylinder bore is no longer standard---it's not far from standard, but it's NOT standard. Therein lies the problem.

A master cylinder that has been honed can be "resurrected", though. Sleeving will bring it back to as-new.

[Patrick H.]

Re: Resleave MC or no? Was: C-3 Master BC

Joe,

In talking with the gents from Vette Brakes, I'd say that calipers are not rebuildable the FIRST time without resleeving. After that, VB states that most of the previously sleeved calipers they get in trade actually just need new seals. As you well know, due to the original seal configuration if the brakes are not used the calipers will start to leak.

It's why I have gone with the O-ring calipers. To the best of my knowledge, they will "never "leak - at least not for that same reason.

Patrick

[Chuck S.]

Did You Use The DYI kits...

From Precision Engineering, Patrick, or did you have them changed to O-ring pistons when they were re-sleeved. What are the pros and cons? I am thinking of retrofitting my restored calipers with O-rings using the kits before even I install them.

[Patrick H.]

Re: Did You Use The DYI kits...

Chuck,

I've had VB do sets for me (send in original calipers, get them back sleeved and O'ed) and I've done them myself.

Don't tell SSBC that I installed VB pistons and O-rings in their calipers. That's the brand of caliper my 71 has on them, and did when I purchased the car.

PH

[Joe L.]

Re: Resleave MC or no? Was: C-3 Master BC

Patrick-----

Yes, that's the point that I was trying to convey---for the calipers, they need to be sleeved the FIRST time that they are rebuilt. Very rarely will you find a "first run" caliper half that doesn't have, at least, some pitting in one of the bores. So, sleeving is necessary in virtually all cases the very first time the calipers are rebuilt.

I haven't used the o-ring pistons yet. There are some drawbacks but for street use, I now think that they're the way to go. When I need to rebuild my calipers the next time, that's the way I'm going to do it.