Front seat 1933 Plymouth PC Master Cylinder

[JBP1933]

The master Cylinder was bone dry and all the wheel were locked up. Pulled all brakes. All wheel Cylinders were completely froze and loaded with rust and gook. Rebuilt back Cyl. replaced fronts. I rebuilt master Cyl.

I could not get a heavy stream of fluid from wheel cyls. when bleeding.

I am asking how the master cyl. is assembled, to check myself out. Everything the was done before on this car was in correct.

Fist goes the rubber washer

The I will call it a check valve flat side toward the rubber washer.

spring, rubber piston cup down, piston seal down hollow in piston for rod up, steel washer, retaining ring.

Is that correct?

I saw a post from (PLY33) about the filler cap. I saw a picture a rew times of this, but it wasn't on mine.

I just have a plug on mine

Does anyone have any input on the slow brake fluid while bleeding. I have no brake pressure at all.

Edited October 19, 2020 by JBP1933 (see edit history)

[ArticiferTom]

Collapsed flex hoses maybe problem . Disconnect at head of each to check flow .

[JBP1933]

Would that cause all to be slow?

[ArticiferTom]

There is hoses on all lines . When one dries out usually all do . Rear are on same one at axle  .

[ArticiferTom]

Only other is compensating  hole leading down in MC . Not allowing fluid to refill after pump, of pedal . This is smaller of two holes to refill chamber .

[JBP1933]

Fronts are new. I'll check the backs. I should have done that when I did the cylinders.

[F&J]

36 minutes ago, JBP1933 said:

First goes the rubber washer

The I will call it a check valve flat side toward the rubber washer.

spring, rubber piston cup down, piston seal down hollow in piston for rod up, steel washer, retaining ring.

Is that correct?

Yes that is correct. 

 

But first check to make sure that there is a slight amount of freeplay in the master cylinder push rod when the brake pedal is fully pulled back by the long coil return spring.  That rod must not be holding the master cylinder piston inwards at bit, as the drilled port in the master reservoir will be blocked by the piston, and not allowing the piston to "grab" more fluid when bleeding. 

 

To explain what Tom said on how to check for internally swelled rubber hoses; disconnect one steel line from the input end of one front brake hose.  Then see if you get flow then. 

 

But best to first test the master cylinder First ! :   have a helper to work the brake pedal, and then you can "bleed" the master cylinder itself, by loosening the fitting on the end of the master.  That should show flow, even if hoses are blocked, but again, you must not have the pushrod too long and keeping the master cylinder piston inwards a bit.  The rod should move a tiny bit before it starts to push the piston.

 

Edited October 19, 2020 by F&J (see edit history)

[JBP1933]

Thanks, There's about 1" of play.

But will check lines. I did blow out the line at the master cylinder when I had them all apart.

[ArticiferTom]

My truck system was dried out and rusted like yours ended up doing all . Plus last was that tiny compensating hole . Could not even see it, had to drill clear with number bit .

[ArticiferTom]

Do you have book Of Information for it with diagrams ?

[ply33]

34 minutes ago, JBP1933 said:

Thanks, There's about 1" of play.

But will check lines. I did blow out the line at the master cylinder when I had them all apart.

 

Depending on wear in the brake pedal pivot, etc. it may not be exactly one inch of play at the pedal. I verified mine by having the cover off the master and gently pulling the brake pedal down from the engine side of the firewall while feeling for the rod to contact the piston in the master and looking for a little spurt of fluid from the relief port (the smaller hole).

 

If you remove the tubing leading from the master and put in a short section the loops back to the reservoir you can pump the master all you want to circulate fluid until the air is out. Basically bench bleeding it in the car. Then re-attach the tubing that goes to the wheel cylinders to start the main bleeding process.

[JBP1933]

Thanks, that what I'll have to do to start narrowing down what's causing it. It has to be a simple fix.

I just keep doubting myself. About did I do this or that.

[JBP1933]

Articfer Tom, No I do not have a book as of yet. I am waiting for a manual in the mail.

[F&J]

12 minutes ago, JBP1933 said:

Thanks, that what I'll have to do to start narrowing down what's causing it. It has to be a simple fix.

I just keep doubting myself. About did I do this or that.

You should definitely bleed the master first like mentioned by two of us.  If the entire system is bone dry, often that makes it impossible to get any flow going.

 

By bleeding the master, that will encourage flow into the lines in a huge way.

[ArticiferTom]

Here is a pic . Not sure if matches . But note number 5  relief hole .