'40 Brake Bleeding
 

Still having a hell of a time getting brakes to bleed. I tried to look at past threads, but can't find this answer.

Did someone tell me to "adjust the brakes until shoes hit the drums and then bleed......you can always re-adjust afterwards".

That's from memory right now. Am I correct ?

Thx.....Mike

Re: '40 Brake Bleeding
 

Mike, it sounds like you have a leak somewhere or a wheel cylinder has dry rubber cups and is just letting air in every time you release the brake pedal. I would disconnect the brake line from the master cylinder and block the port and see if you get a hard pedal when you bleed. If you do get a hard pedal, then hook up one brake line at a time until you find the one wheel that gives you the soft pedal. Yes, you will have to have some plugs to block off the lines at intersections and at backing plates.

Re: '40 Brake Bleeding
 

Forty...... thx let me check that out.....also should I adjust the brake shoes out to touch the drums ? I'll buy the plugs today. May not work on it today as we got 2" of snow last night and it's 18º now !!! Geez....

Thx....Mike

Re: '40 Brake Bleeding
 

Mike42
Did you just do a "recent" brake job and or replace wheel cylinders by chance??? OR replace shoes???


As for adjusting them, I adjust the bottom first, I bring them out to where they just contact the drum and do a "very slight" back off from touching. Then do the same on the top...just ever so slightly before touching or drag!!!! It shouldn't matter IF you do this before or after bleeding!!!!


The reason for asking the first question IS. I was talking with Mike at Third Gen when I was working on my 39 Merc brakes and he was telling me about "some" of the after market shoes and wheel cylinders THAT the tabs on the shoes where they fit the wheel cylinders are a little long and thus push the cups further inward on the wheel cylinder. It allows for bleed by on the cups and you can't get a hard peddle. IF you did put new shoes and or cylinders on, you might want to pull the rubber caps on the cylinders and SEE IF there in fluid behind them......IF so (and you also replaced your shoes) you may need to pull the shoes back off and grind the tabs back a little bit!!!!!

Re: '40 Brake Bleeding
 

Rock......I turned drums, replaced shoes and wheel cylinders as well as the master cylinder. i'm getting fluid to each wheel, but will not bleed as they should. I will check the tabs out for sure.

Cold and snow today so when it warms a bit.

Thx....Mike

Re: '40 Brake Bleeding
 

Also.....Are you using silicone brake fluid??? That will also make your peddle a little "softer" than normal. I was having the same issue with my Mercury.....BUT Mine ended up just being "lots" of air in the lines!!!! SO i ended up bleeding mine 4 times to get all the air out, finally a really nice peddle even with silicone fluid!!!

Re: '40 Brake Bleeding
 

Mike42
Just in case, here is "from the Ford Service" book!!!!

Re: '40 Brake Bleeding
 

Did you "bench" bleed the master cyl. before you installed it?

Re: '40 Brake Bleeding
 

Rock ....thx for pages ! I'm using DOT 3 Fluid.

Alaska....I tried to bench bleed and was not very successful I'm sorry to say. That may be a big part of my problem. I have buddy looking into it now also, as I'm running out of time. As a side note I lived on Ladd Air Force Base in '51, '52 and'53 in Fairbanks. Great part of my life !!

Thx all....Mike

Re: '40 Brake Bleeding
 

Rock ....

Can you send me those photos a little larger. Very hard to read when printed and some areas don't come out well at all.

[email protected]

Thx....Mike

Re: '40 Brake Bleeding
 

My file and edits

Re: '40 Brake Bleeding
 

I have never had to bench bleed single chamber master cylinders. Didn't that come into practice only after the introduction of dual chamber masters?

Re: '40 Brake Bleeding
 

You are correct sir. There is zero reason to bench bleed a single master unit.

Re: '40 Brake Bleeding
 

Glenn .....thx !

I worked on it all day yesterday and I'm having a hell of a time getting anything to happen. I don't know. I may take it to my Buddy's Shop and have him see what he can do.

Thx....Mike

Re: '40 Brake Bleeding
 

Glenn....printed out big and great !

Thx again...Mike

Re: '40 Brake Bleeding
 

I have found that new production wheel cylinders need to be taken apart and inspected, some have the holes drilled wrong, the feed holes drilled off center (cut the shoe tab so the piston is out more to uncover the hole??) and bleeder holes not going to the top of the cylinder --you can't get the air out!!
Even rebuilt ones need taken apart i have had leaks in them because the shavings were not cleaned out

Re: '40 Brake Bleeding
 

Since the weather has been good I've tried a few more things with no luck at all ! I had it trucked down the my Buddy's shop and we'll see what he can do with it. Would sure love to be driving it with weather like we've had here !

Kurt...I'll mentioned your idea with my friend. Thx...

Mike

Re: '40 Brake Bleeding
 

Kube, tubman, I was not aware that the single chamber master cylinders did not need to be bench bled, I have always done it though. thanks for the information, good to know.--Jim

Re: '40 Brake Bleeding
 

correct and dont push them all the way to the floor..
long steady strokes... :D:rolleyes:

Re: '40 Brake Bleeding
 

I turned drums, replaced shoes and wheel cylinders as well as the master cylinder. I'm getting fluid to each wheel, but will not bleed as they should. I will check the tabs out for sure.

Mike. I have read this post several times, and I'm not sure what the problem is. You say you can't bleed the brakes properly, so I'm going to assume you can't get a solid pedal. You say in post #5 (as above) that you turned the drums and installed new shoes. Did you have the shoes arced to match the turned drums? I'm only guessing here, but if the shoes don't match the drum radius, and only contact the drum at mid point of the shoe, is it possible that the shoe would flex, like trying to straighten out a curved spring , thus causing a soft pedal?