The Stovebolt Site Forums The Shop Area Driveline Brake bleeding

So I upgraded my 53 to cpp front disk brakes, rears are still original drums, after bench bleeding the Mc, and the fronts and rears ,can not get a firm pedal, don't see any visible leaks anywhere.? Using the one man vacuum pump for bleeding.

Vacuum pumps are OK for getting the majority of the air out of the system, but it's still a good idea to follow up with either a pressure bleeder or the old style pedal push bleeding job. I like to fill the MC and open all the bleeder screws a little, to "gravity bleed" most of the air out, then do a pedal pump bleed job. Just don't work the pedal up and down vigorously- - - -push it once and hold while a helper operates the bleeder screw.

Some disc brake calipers flex a little under firm pedal pressure, giving the impression of a spongy pedal.
Jerry

CPP master? My pedal was always like that. Didn't change until I installed a Wilwood master.

I’ve had high hopes in vac bleed tools, really wanting brake bleeding to be a one man affair. I’ve never been satisfied until I had a helper to pump for me.

I bought the vacuum pump from HF a few years ago, thinking the same thing. I used that pump several times since on not only my ‘52 but also my daily driver. I was never sure all of the air was out, until I had my helper (my wife) pump the pedal, bleeding the old fashion way.

A 2 x 4 or such braced between brake peddle and front of seat or supports works fine for one person bleeding, since kids have all run off!

Ed

I use one of those marine engine oil through the dip stick sucker deals as my vacuum brake bleeder, it has a lot of capacity, and pulls a good vacuum. I never have someone to help with bleeding brakes. And have never bench bled a master cylinder, tried it one time and it just didn't' work and made a mess. Pressure bleeder? very easy to ruin some paint with them when the seal feeding the MC lets go, been there done that in the past. Vac is the cleanest and safest way to go. A mushy peddle can also be the adjustment of the rod into the mastercylinder, positioning the piston in the wrong area.

One thing I would caution you about is the capacity of the master cylinder. It’s so small, constant checking of the level is required otherwise you’ll run the MC dry, complicating the issue, especially with any type of power bleeder.

I hate brake bleeding. Since buying a used reverse pressure bleeder, I hate it LESS. A lot less.
I can bleed my brake lines myself. The setup I use is for reverse bleeding. I hook the pressure pot hose to the open bleeder valve and pressurize the pressure pot (partly filled with DOT 3) and then walk to the MC and watch the bubbles stream up through the MC port. I have a bulb syringe (ear syringe bulb works great) handy to prevent overflow of the MC. When bubbles stop, I release pressure from the pot and let it gravity drain a few seconds before tightening the bleeder and moving to the next bleeder. I LOVE this method because bubbles want to flow uphill, it’s quick, and I can do it without a helper.

I have the same Motive system except With the universal plate to pressurize fluid into the master so you bleed in the working direction. Worked great for 1 person bleeding. Pedal downright stiff on corvette style dual master installed in my46. Used c clamps instead of supplied ‘j hooks and chains’…..
Didn’t know they made a reverse bleed adapter…better for stock MC with sealer cap?
Pressuring fluid to the master means set it up and bleed all 4 corners, as in 1-2-3-4 done, (not setting up 4 times in reverse bleeding).

Would I buy it again? yes!
Chuck

With these "reverse" pressure bleeders how do you drain off the mastercylinder? Special cap with a hose and a stand off down in about a half inch?

With the MC cap off, I observe bubbles and fluid entering the MC and drain off excess using an ear syringe to prevent overflow of the MC. When bubbles stop flowing for at least 15 seconds I then go and release pressure from the pressure pot. Gravity will cause brake fluid to flow downhill for a few seconds at which point I tighten the bleeder.

Easy to get a good spill, not catching it in time. With a drain setup like I mentioned, a person could do all 4 wheels and not worry about sucking out the fluid. How much and where to get those bleeders?

I concur that either way works well. It’s simply a matter of owner preference. Makes no difference to me which way it’s done.
Bleeding from the MC towards the brake bleeders is logical and efficient. However, in my experience there is a chance of the MC fluid level getting too low on that LAST brake cylinder. Then air enters the lines and whoops!
The reverse method has the same risk of air in the lines if you underfill the pressure pot.
I’ve never had the MC overflow because I use the bulb syringe to remove fluid so the MC never gets more than half full. Fluid flows slowly enough to give you plenty of time.

Would this work with master cylinder under floor and remote fill mounted on firewall? Thanks

Motive products are available at the usual hot rod suppliers (like Summit Racing)
Works on my 46 with underfloor Master, though I have a modern split system m/c.
I imagine It will work fine on a remote fill system, just be aware the remote hose and all connections need to reliably hold 10-15 psi.
Motive has a number of master cylinder adapters and options, you need to dig thru and get one that best serves your system.
The system is sending brake fluid under pressure into the m/c, so if you have enough fluid in the Motive tank you don’t think about the m/c getting empty.

Chuck

Thanks I looked at summit, confused on which one to get, 53 ,3100 with cpp front disc brakes and mc and booster under floor, remote fill on firewall. Stock drum brakes.