Make it Stop! ('46 Deluxe)

[FortyNiner]

Looking for some help from the brake experts on the Barn (that would be anyone who isn't me).

Here's the deal:

'46 Deluxe Tudor
Bone stock

As part of my resto, I replaced:
Master cylinder (twice - as part of my trouble shooting efforts)
Wheel Cylinders
All lines / hoses
Shoes
Springs

The drums were not changed.

After reassembly, I have adjusted the shoes so they are just off the drums.
The MC was bench bled
The whole system has been bled at least four times
The system doesn not leak anywhere

Here's the issue: I have very poor to no pedal pressure. if I pump the pedal a few times, the brakes will function and stop the car. Needless to say, this doesn't make for a safe ride. Searching the Barn gave me some tips - that I have followed - without real improvement.

My question: What am I missing? What did I do wrong? Should I do the Bendix conversion?

Thanks!

[petehoovie]

Are you using DOT 3 or Dot 5 brake fluid?

[FortyNiner]

Fresh DOT 3 fluid.

[19Fordy]

Remove each drum and rub chalk dust on the complete surface of each brake shoe. Reinstall drums and take car for a drive making repeated stops. Then remove brake shoes and see where the chalk dust has worn off on your brake shoes, showing actual brake shoe contact with drums. Also, I have read on Fordbarn that it's a good idea to "taper" the end of each brake shoe lining so that the shoes make better contact with the drum.
Of course, the best thing to do would be to "arc" the brake shoes to make sure they "fully fit" the drums. Others, may have better suggestions but, that's a start.

[marko39]

Could still have air in system. How did you bleed them?

[FortyNiner]

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The MC was bench bled. The lines and wheels were bled with a helper pumping /holding the pedal as I opened and closed the bleeders that had a clear tube attached. Considerable fluid was pumped through the tube (the MC was not allowed to empty) with no signs of bubbles.

[cmbrucew]

When you said all lines were replaced did that include a nice loop up and down to clear something?


Bruce

[FortyNiner]

Originally Posted by cmbrucew

When you said all lines were replaced did that include a nice loop up and down to clear something?


Bruce

I'm not sure what you mean. The lines run true to the factory placement.

[supereal]

Old Ford brake systems can be difficult to fully bleed because the master cylinder is below the wheel cylinders. With patience, and a couple of gallons of fluid, it can be done. Before you go further, have the system bled with a power bleeder at a shop who still knows about drum brakes. Our bleeder is a small tank on wheels that we pressurize with compressed air. Start with the wheel farthest from the master, at the right rear, and work your way forward, being sure each bleed screw is closed when done. We place a tube on the bleed screws and the other end in a clear bottle to observe any air bubbles remaining as we bleed.

[JSeery]

I agree with the air in the lines. Air is getting trapped somewhere or is getting sucked into the system from somewhere.

[FortyNiner]

Originally Posted by supereal

Old Ford brake systems can be difficult to fully bleed because the master cylinder is below the wheel cylinders. With patience, and a couple of gallons of fluid, it can be done. Before you go further, have the system bled with a power bleeder at a shop who still knows about drum brakes. Our bleeder is a small tank on wheels that we pressurize with compressed air. Start with the wheel farthest from the master, at the right rear, and work your way forward, being sure each bleed screw is closed when done. We place a tube on the bleed screws and the other end in a clear bottle to observe any air bubbles remaining as we bleed.

Excellent! Thanks for the guidance.

[FortyNiner]

Gratuitous beauty shot.

[Charlie Stephens]

Did you have the shoes arced to the drums and how far out are the drums? Hold off on the Bendix conversion, it is nice but $$$. Your brakes should work when you figure out the problem.

Charlie Stephens

[alanwoodieman]

did you adjust the brake pedal to mc rod correctly? should have a little rattle and no end play when adjust correctly. pedal should move just a little before slack is gone

[petehoovie]

Originally Posted by FortyNiner

Gratuitous beauty shot.

[V8COOPMAN]

Originally Posted by FortyNiner

Should I do the Bendix conversion?

Thanks!

You sure will like the Bendix brakes....you'll never look back. If that's what you decide on, DON'T attempt to save a few bucks by going any of the "cheapie" routes. Go to and order from MT Car Products. There is another "big name" outfit selling similar Lincoln-type Bendix brakes and many folks are having trouble with their brake drums of unknown origin. Go look at genuine MT Car Products pieces in the link below! The best part...these Bendix brakes function really well when used on the FRONT of your Ford in conjunction with the ORIGINAL, stock brakes in the rear since the rears apply such a small percentage of the overall braking effect. DD


http://www.mtcarproducts.com/productsgrid.html

[FortyNiner]

I didn't have the shoes arced or the drums turned or checked. The MC rod was adjusted to minimize play. Once I have a more firm pedal, I'm expecting to encounter the next layer of issues. Will keep these in mind going forward. Appreciate the input.

[TJ]

Charlie brings up a good point regarding the drums. Even though you did not turn them they may have been turned before and turned too far.

[Charlie Stephens]

Contact the local Early Ford V8 Club and the local Model A Ford Club and find out who the members use for brakes. There are a lot of Model A Fords that have been converted to the later hydraulics like yours. Finding someone to work on your brakes will be difficult. Most shops no longer have the special adapter to turn the rear hub. Most of the shoe arcing machines have been taken out of service due to OSHA requirements to fit them with special filters to trap dust. Don't take them to a shop that doesn't know how to work on the early Ford brakes, they can do a lot of damage. It will take a little chasing around but I really think it is the solution to your problem. Please keep us posted.

Charlie Stephens

[Terry,OH]

When you adjust the brake cams do have some drag to each shoe.

[Kurt in NJ]

Some offshore production wheel cylinders have the holes drilled wrong, sometimes the bleeding port is not drilled to the top of the cylinder trapping air ---- just because the part is new doesn't mean it is good, I learned to take apart new wheel cylinders for inspection

[FortyNiner]

Originally Posted by Kurt in NJ

Some offshore production wheel cylinders have the holes drilled wrong, sometimes the bleeding port is not drilled to the top of the cylinder trapping air ---- just because the part is new doesn't mean it is good, I learned to take apart new wheel cylinders for inspection

Fair point. The wheel cylinders were from an old hot rod builder who was emptying his shelves. Not sure of the origin beyond his garage. One of them was defective - the bleeder threads wouldn't seal.

[FortyNiner]

Originally Posted by Terry,OH

When you adjust the brake cams do have some drag to each shoe.

Yup. Played with the cams to do this.

[TJ]

Originally Posted by FortyNiner

Fair point. The wheel cylinders were from an old hot rod builder who was emptying his shelves. Not sure of the origin beyond his garage. One of them was defective - the bleeder threads wouldn't seal.

If those wheel cylinders sat around on a shelf for any length of time they may have attracted moisture inside and the pistons don't move smoothly or one side may be stuck in position. Did you take them apart and inspect them inside before you installed them? If you are not sure of the origin of those cylinders maybe they were there due to them being defective?

[alchemy]

Arcing the shoes to the drums will make a huge difference. Since I don't have anyone with the proper machine nearby, I use a sanding block with 80 grit on it to sand off the high spots of the shoes. Then check again after a long drive. It's gotta be better than nothing.

You say that you adjusted the cams. Are your lower pivots nice and loose to allow the shoe to move properly? I bought some new shoes from Carpenter (mine were for a 40 but might have the same problem with shoes for other years) that were too thick of metal at the pivot point. The brass pivots were thinner than the shoe, so the clamping bar grabbed the shoe and wouldn't let it turn like it needed. I had to grind the shoe thinner at that spot to let the pivot work.

[FortyNiner]

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The fellow who sold me the cylinders was reputable and I didn't disassemble them before installation. That's part of my trusting nature, I suppose. Bear in mind, the brakes do work well - but only after a few pumps on the pedal.

All the under drum mechanical stuff seems happy. The shoes move as they should and the pivot points free.

[Talkwrench]

There is a likelihood that your drums might be too far oversize, just because new linings go in doesnt meant it will work, standard linings off the shelf might not work.
Also try some speed bleeders and dont push the pedal all the way to the floor when bleeding do it nice and slow.

[john in illinois]

I would suggest measuring the diameter of the drums. If they are too far worn you will not have enough stroke to push the shoes out the first pump.. In that case usually a second pump will get brakes.

John

[FortyNiner]

Problem Solved!

Again, thanks to all who responed - with a special callout to Supereal. Much appreciated.

Here's how things got fixed:

1. Installed speed bleeder valves
2. Bled each wheel such that the tube attached to the bleeder valve kept the valve wet. No air was allowed at the end of the bleeder.
3. Much patience with exercising the brake pedal.

This was really more about burping the system than bleeding. While some air (and fluid) was pushed out the WC, most of the air exited at the MC.

The result? A firm pedal that can lock up the wheels at will. Yaahoo!

Why did the fix work?

As I watched the MC during the bleeding process, it seemed that even with traditional practice of 'open valve, push pedal, close valve, release pedal' air was entering the line. Could have been sloppy technique (any fault was mine, not the helper), could have been sunspots, could have been bad mojo. In any event, the speed bleeders and a carefully positioned tube did the trick.

What's next?

I didn't ignore the comments about shoes and arcing. I'll take a look at the contact points between the shoes and drums and make adjustments as needed.

The honor of the first to ride shotgun went to my 86 YO FIL who owned a '37 3 window coupe and a '47 Fordor at points in his car owning past. He was also one of my 'rent-a-leg' helpers.

It was a good day. Thanks for playing along.

[tubman]

Excellent! I'm very glad that you have this solved.

And a large "Thank You" for getting back to us with the method and results. It doesn't happen often enough.

[JSeery]

Thanks for the follow up!