Hydraulic Brake bleeding problem

[GPierce]

A friend of mine and I trying to sort out a brake bleeding problem. His customer brought him a 31 A with a brake conversion using 39 to 42 backing plates. As near as we can determine it has never worked right. He bought the A with the conversion all ready on it. All indications are there is air in the system. Blocking off the rear brake line the front brakes work. Blocking off the rear line we have no brakes and the pedal goes all the way to the floor. Bleeding the rear brakes yields no air or bubbles, just fluid.
Investigation shows the wheel cylinders are mounted on the bottom of the backing plates so the shock levers clear; backing plates turned upside down. This causes the fluid to come into the bottom of the cylinder with bleeder port above. It is our opinion that this results in air being trapped in the top of the cylinder and bleeding won't remove it. See attached picture with orientation the same as the mounted on the backing plate. You can see the bleed port on the bottom of the cylinder with fluid supply port above it.

How do those of you use tghe 39 to 42 backing plates solve this probllem?

[Keith True]

What are you using for a master cylinder?Single? Dual?

[GPierce]

Single

[johnneilson]

Rotate the backing plates so the wheel cylinder is on top.
The centerline of the cylinder to the retaining boss is offset so just inverting the cyls in the backing plates does not work.
I have looked at some installations where the cylinder is not rotated completely to the top, it works but still can have fluid bleeding issues.

J

[Model A Ron]

Never had a problem blending my mechanical brakes and they stop wonderful ��

[denis4x4]

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Originally Posted by Model A Ron

Never had a problem blending my mechanical brakes and they stop wonderful ��

I’ve had problems “BLENDING” my hydraulic brakes, but never a problem BLEEDING them. They stop on a dime with a nickel change.

[Phil Brown]

Disconnect shock links, mount backing plates with wheel cylinder at the top (like it should be) bleed brakes, without removing any lines after bleeding rotate back to the bottom.
A lot of guys do like johnneilson said and leave the wheel cylinder at the top but rotate it about 15° just enough to clear things by redrilling the mounting holes