The Stovebolt Site Forums The Parking Lot Big Bolts How to clean original 57 Chevy Master Cylinder?

Hey guys! I stopped in at the "Welcome Center" and had a great
welcoming! Thank you!

BUT, on to business

I have a rebuild kit for my master cylinder, and am hoping it will rebuild alright *crosses fingers*

but before I do so, I was curious as to how you guys would recommend I get it somewhat new looking?? I don't have a parts washer and etc. I am looking into picking up a sand blasting unit for prepping the frame for paint. Would it be safe to use something like that?

Right now my MC is sitting dry, and in the back of my mind I'm afraid of certain parts rusting out, but I'd like to possibly not re-install until the frame is repainted. Will it be ok you think sitting in my shop until then?

I am new to most of this, I can say my only skill lies in body work (amatuer) and electrical (intermediate).. I'd have to lay my mechanical skill in the beginner realm ;-P Hopefully I haven't bitten off more than I can chew.

Here's a pic of the MC: click here

I sandblasted the exterior of my MC.

Before:
https://picasaweb.google.com/113636046886857960240/BrakesBearings#5518798985884842018

After Blast:
https://picasaweb.google.com/113636046886857960240/BrakesBearings#5518799000073418450

https://picasaweb.google.com/113636046886857960240/BrakesBearings#5518799018775324434

after paint:
https://picasaweb.google.com/113636046886857960240/BrakesBearings#5527351318953822786

Just made sure I flushed it clean with brake cleaner before reassembling. I also blasted it with it closed!

Hey Streamylc

Sandblasting the exterior would be OK as long as you INSURE that not a speck of sand gets/stays inside the "working area"

But all of that is un-necessary...
Disassemble and hone the bore with the proper sized ball-hone.
Coat the interior with Vasaline, then plug/seal the bore and ports how-ever you can.
Wire-brush exterior down to metal, then degrease with POR-15's "Marine Clean"
Prime and paint your favorite color.
Let it sit on the bench until you're ready ... brake clean the
Vasaline ... go

-Hd

Thank you bigtonka!!!

I've heard about honing the cylinder? Did you have to do this?

I'd imagine it would be pretty apparent if one needed to hone it?

Wicked!

Do I have to be afraid of damaging anything honing it myself? I saw a honing attachment for a drill(etc) at harbor freight, would a "honing ball" be better to use?

I did not. It's pretty easy to check - if the cylinder has any pitting at all - you should repair or replace.

I'm not sure that the cost of a 57 MC is, but for my AD it's about $100.

Yeah.. mines around $120 which isn't too bad, but it's $120 I don't have, considering I don't even have a battery for the truck right now ;-P so if I can rebuild it, I'd have to skip with joy. I looked in the cylinder itself and it looks like a baby's bottom... no imperfections that I can see

If I'm not mistaken, rust would have to be present to cause the kind of pitting we're talkin about? If that's the case, when I first opened it up it looked straight outta the factory (clean metal wise)

Sounds like you're off to the races!

Since we're on the brake subject, and I don't want to flood out the forum with question upon question

Should I replace these brake lines? I can't imagine them looking much worse, will they contribute to ruining my wheel cylinders? Rear Brake Lines

And when I do go to fill up the system, where in the heck do I bleed from on the rear?!?! Which nut?

I'm guessing(blind) the smaller clutch nut between the two hex bolts on the left?

Sorry I have to chime in here guys...

Brakes on a med/heavy chassis truck are nothing to short-cut ...
It's OK if your 14,000lb truck won't go, but it's NOT OK if it won't stop... that's a recipe for a bad day at the office.

It doesnt matter what the cylinder 'looks' like, it MUST be honed with new piston/seal placement ... even if you use the two-finger method.

Brake lines can be inspected for abrasions/corrosion and fitting integrity ... if all good, flush and put them back to work.

Wheel cylinders should be re-built or replaced.

with all respect
-Hd

Sounds kinky.. What is the "two finger method"?? juusssttt kidding but seriously, I don't have any honing equipment.. The two finger method sounds cheap ;-P

I was told the wheel cylinders were just recently replaced. Atleast I hope they were, getting to them doesn't sound too fun

Brake lines will rust from the inside out. DOT-3 Brake Fluid wicks moisture. Since you are this deep into the brake job take the time to replace ALL of the lines, steel and rubber. You'll sleep better knowing everything is new and done right. This is one area you don't want to cut corners.

Be safe...

Mike B

Thanks Mike! and my brake system thanks you also!

Tried searching this "two finger method" for honing on google.... ended up back at this post!

Wrap a piece of 220 wet/dry sandpaper around two of your favorite fish-cleaning fingers.
Don't let your girlfriend/wife watch otherwise she'll keep you up all night.
Cross-hatch the bore with your home-made hone, keep everything moving with ample doses of WD-40.
Repeat with 400 wet/dry
Clean with brake fluid, stand back and admire your as-new cylinder.

I take my master and wheel cylinders down to a local machine shop. They let me watch as they use a Sunnen hone on them. They take .004" to 010" out of them for around $4-$10 each. If there are still pits in them, it depends on where the pits are. If in the center of the cylinder it can be OK. If it is where the puc seal rides, then it isn't. I put a new kit in them and they work great. I don't let them run a ball hone in them afterward either. Staight off the hone and then brake clean. Lube them up with brake fluid when assembled.

can't wait to try this!!

If I fail though, I located an at home machinist halfway to the city that might be able to help me out for a "couple" of bucks

I can't imagine doing the truck over and not replacing the brake lines. You can buy new lines and bend the steel ones to fit. It looks like you have two wheel cylinders on each back wheel. If that is the case, bleeding the system is tricky. You must have a Hydro-vac booster and they are tricky to bleed too. When you are finished you will have a large heavy truck that stops quickly with very little effort.