[dataway]

Anybody have suggestions for a good bench bleeding setup for a MC? My usual methods are very messy and annoying, would be nice to hear what others are doing.

This is a 68 all drum, power brake MC with bleeders on the MC.

Thanks

[JLMounce]

I have never been able to successfully bench bleed a master. As you state, it's messy, annoying and I always fight air in it regardless. I've tried the looped hose method as well as the method where you simply depress the piston and plug the outputs.

Perhaps my technique isn't correct, that's certainly a possibility.

What I do now when I need to bleed a master is reverse bleed. I purchased the cheapest reverse bleeder I could find to try it out and it gave me a great pedal right away. The idea behind them is that air naturally wants to travel upward, so why fight that? I started with just enough fluid in the master to make sure the valves were completely covered. Then, starting from the farthest caliper and working towards the nearest, reverse bled through the calipers, up the lines and into the master.

Because I can't leave well enough alone, I've been through 3 master cylinders, 2 boosters and a complete set of calipers and rotors in the past 4 years and that little plastic part has saved me countless ours of bleed time and a whole bunch of wasted fluid.

[Skip Fix]

Best way I have found is plugging outlets then doing it until it gets hard as heck. You and leave the cover on so it is not as messy.

[Cammer-6]

Many year ago I bought a Phoenix pro injector.
It works on ABS systems without turning on the ABS solenoids.
It also does the Ford Ranger clutch,which is very contrary
If its not all fresh fluid,I would flush first,you can do that with the injector
by attaching at the brake line where it attaches to MC.

Heres a used unit for 1/3 new cost

https://www.ebay.com/itm/23691922465...iABEgJILPD_BwE

[Sirrotica]

I never bench bleed master cylinders. I install them, leave the fittings slightly loose, and just bump the pedal at the top of it's travel about an inch and let it return several times, and tighten the fittings. The air is forced out around the fittings and bleeds very fast. By doing this slight movement at the top of the travel allows any possible trapped air to return via the ports into the reservoir.

When you have no helpers, you find ways around the conventional methods. Been doing it this way for over 50 years, so I've done dozens and dozens this way.

I also use gravity to bleed brake systems, which some people can't wrap their heads around. Physics never changes, air rises through a column of fluid, and fluid falls in a system, basic physics. I don't make things more complicated than they need to be. YMMV...............

[Skip Fix]

I had problems with my 64 Vette project adding a dual MC and front discs overcoming the residual pressure valve for the drums with gravity bleeding. We had to do the 2 man deal on bleeder making pressure on the pedal.

[dataway]

Thanks folks, gives me several options.

Anyone else hate the feeling of brake fluid on their hands?

As much time as the car spends just sitting in my garage gravity bleed might work. In the past I've mostly used a vacuum bleeder for the lines, but usually I make a mess doing that too.

I haven't touched the lines, just removed the MC, but I'm sure some fluid has climbed out of the lines while the MC was off.

[VCho455]

I bench bleed with hard lines I have made out of old lines. I firmly believe that using plugs in the ports will prevent me from getting all the air out of the master cylinder (depending on the cylinder piston design). The switch to plugs from hoses in bleeding has more to do with the economics of the parts manufacturers than proper bleeding. I do find the plugs handy after I've completed the bench bleeding to prevent fluid from leaking while I install the master cylinder.

I also do not have faith in the mis-named "Gravity bleeding". In reality it is siphon bleeding and will only work if the lines and components on the vehicle will allow a proper siphon to form and pull the air out. It is also messy unless you have 4 bleeders that have been drilled out to attach hoses to direct the fluid into containers. I have found that using a hose on a unmodified bleeder can cause air to be sucked into the lines by the siphon.

These are my opinions from 40 years of bleeding cars, trucks, and hydraulic controls on tugboats. And we all know my opinion along with a sawbuck will get you a steaming hot cup of Joe just about anywhere. 🙂

[Sirrotica]

Over 50 years making my living working on fluid systems in cars, trucks and hydraulic construction equipment, and never had one machine that I had to send to the crusher because I couldn't bleed a fluid system properly. It may not be easy, and it can be messy, but it's surely doable.

As I said, earlier, some people just can't wrap their heads around the properties of physics, and have trouble bleeding fluid systems. Understanding how these systems were engineered to work tends to make the process easier.

I guess you have to know how physics work so the air doesn't outsmart you.........

[P@blo]

Factory service manual states use the Kent Moore J-26819 to bleed the master cylinder.

[dataway]

If it makes a difference, my MC has the extra bleeders on the MC line ports.

Almost makes me think I could just fill the reservoir and open those bleeders.

[Sirrotica]

Same as bleeding it with the lines loosened in place, and yes it will work.