The Stovebolt Site Forums The Shop Area Engine Shop Master Cylinder Prep

I am at the point of bleeding my brake lines. Should I prime the master cylinder outside of the truck on a bench?
Or can I do it now that it is installed in the truck? I am using the pump style brake tool to do the brakes.
Thank you!

Fill it with fluid and bench bleed it. It will make life a lot easier for you.

UnklRod,

If your are using a vacuum bleeder, pull the bleeder valves and wrap them with 2-3 turns of Teflon plumbers tape. That way, you won't suck air when you are trying suck brake fluid. Leave the tape in place when you are done, it improves the seal.

Just went to NAPA and bought a master cylinder bleed tool. Cheap $6. Screws into the outlets of the MC and then feed the rubber line back up into the reservoir.

Teflon tape on the threads wil help duting bleeding by keeping the it from sucking air around the threads of the bleeder, but will serve no purpose afterwards as far as sealing. The bleeders seal against a machined seat in the wheel cylinder/caliper. the threads do not seal gainst the fluid like a pipe fitting. The tape will prevent corrosion in the threads, though.

Bill,

You are right on both counts.

The new MS I got from NAPA seems to still be leaking. I clean the little rubber boot in front of the MS of fluid and then come back a couple of days later and it is wet again .
Also, the ss lines are leaking at the WS and at the T back on top of the drive-line where the lines split to go to the 2 rear wheels. I have checked and re-tightened all the lines..they still seem to leak..

Any ideas????

OK I am done and tired.
This truck is starting to take its toll on me. I have no idea what I am doing wrong. All the fluid drained out (somewhere) of the MC. I went to look in the reservoir and it was dry. I know the WC are leaking and blisterd the backing plates of 3 of the wheels. It was also leaking at the brass splitter above the driveline as well. When I left the MC was full. I dont get why the ss lines are leaking at the WC. The lines are as tight as they are going to get. I bought the WC and MC at NAPA. Is there anywhere I can get a MC and WC MADE IN THE USA? I am tired of this aftermarket China crap that is the only choice I seem to have.

i would rule out leaking from bleeder screw or leaking from inside wheel cyl or leaking from incoming brake line. you can get a orig and rebuild it and it's made in USA! good luck!

Napa has good stuff & warranties. If it is leaking take it back. That is pretty rare for a new master cyl. to leak. I do like Hoggy say's & rebuild my own unless it's pitted bad. A guy could get bad parts in the kit also though. Iv'e never used SS lines. Did you flare them yourself orwere they factory flares. I use steel lines & usually flare one end myself. The ones I do leak sometimes but the factory ends never do.

Got mine from Jim Carters.......had no problems with leaks, etc.

Hi Wrench,
The ss lines came factory flared. I got new MS today from NAPA. Will bench prep the MS before installing. I found out that I need brass washers for the banjo bolt.
I will let you know how things go.

OK,
Just spoke with Filling Station and they do not carry the banjo bolt, brass block, and brass or copper washers that go on the end of my stock MS . Anyone know what else I can use for the two lines that mount on the block?? OR, know where I can get these parts?
Thanks!

wasa matter w/ the ones you picture?
the copper washers should be available at NAPA, if your block is bad you'll either have to find good used or look at NAPA's collection of brake fittings and fake it, there is a way to do it

Bill

Hi Bill,
NAPA does not carry the washers....thought that was weird.
I think the washers are bad. I will keep looking. I will also see if I can clean up the fittings and see if that will do the trick.

Thank you!

Make sure you have the copper seal on the front rubber brake hoses where they go through the frame. I though my master cyclinder was leaking too.

I don't know what size you need, but Dorman / Motormite has a selection of banjo bolt washers that are available through O'Reilly Auto Parts.

regards,
Leon

Hi Leon,
Will go check that out at my local O'Reilly.

Thanks

Carquest has the assortment package too in the Motor mite Help line.

Is there a brake fluid out there that does not flake paint? If there is can I run it in the lines even though there was regular brake fluid in there before?

There are silicon-based brake fluids that do not affect paint, but they are not particularly suitable for a street car. Do a Google search for lots of opinions and a handful of facts.

There are also paints and other coatings that are insensitive to glycol brake fluid. Some of the POR15 offerings come to mind.

regards,
Leon

DOT 5 silicone brake fluid won't harm paint but the system has to be completely changed of the old fluid. It's use is controversial. There have been many discussions on it. You might find some of them in a search. I wouldn't use it.

Yes this what I am hearing as well...
Oh well,,,I will just repaint everything once I get the leaks to stop.
Thank you all anyway!

Jon

When installing the banjo bolt and brass block with the washers...does it matter how tight I tighten down that banjo bolt into the master cylinder? Is there a certain way to do it?
Still leaking from the brass block.

Thanks!

Is there a different way to go with this set up? Can I keep the original style master cylinder but replace the banjo bolt with something different??

I saw on a 58 and 59 they changed the system to a tri connection. I might try that if I am unable to reuse the banjo.