Brakes

Woodie1

Well-known member
I have several issues going on. We have a 1939 & I just replaced all wheel cylinders & the master. I have also replaced the 3 flex hoses. There was too much crud appearing at the wheel cylinders. My 1st problem is there isn't a brake pedal return spring. I bought one & can't figure where it should hook to. I looked in the parts book & it says the spring should be 17.3" long. The one I got is a lot shorter & doesn't look like the one in the book.
The next item is we have bled the brakes at least 10 times & the pedal still goes down about 4" leaving 3" to the floor. I can't see any leaks at the fittings. We have tried pumping the brake pedal slowly & holding it to the floor on the 3rd. pump & then opening the bleeder screw & looking for bubbles. We start at the passenger rear, then driver rear, then passenger front & driver front.
I've searched the Ford Barn for brakes & I can't find any clues to what we are doing wrong. I've included a couple shots of the frame where I think the spring should be. I think the speed o cable may be in the wrong spot.
 

Attachments

  • Frame 1.jpg
    Frame 1.jpg
    33.5 KB · Views: 38
  • Frame 2.jpg
    Frame 2.jpg
    44.9 KB · Views: 34
Did you bench bleed the master cylinder before you installed that??? IME IF you didn't you play hell getting ALL the air out of the lines.
 
Last edited:
From everything I have read on the Barn & online, they say if it's a single reservoir, then bench bleeding isn't needed.
 
The spring can go near the oblong slot in the chassis in front of M/C about a third along on the side or bottom 1" tension drill a 1/8 hole ,Make sure your shoes are adjusted place a rag in the M/C fill hole 1/2 filed .Use a air gun and blow at 40 psi into the rag with one bleeder at a time open ,Wheel cylinders must match the M/c
 
Last edited:
Luckily (or not luckily), I have my 1940 apart. This is what it looks like on mine. Thinking a '39 might be similar. The spring is only 3 or 4" long. This view is from inside, over the trans cover. Hope this helps.
 

Attachments

  • PXL_20230328_192722398.jpg
    PXL_20230328_192722398.jpg
    74.8 KB · Views: 89
  • PXL_20230328_192737804.jpg
    PXL_20230328_192737804.jpg
    73.8 KB · Views: 81
Flathead Ted, what do you mean the wheel cylinders must match the master? Nick, the spring I have looks nothing like yours. The clutch spring does though.
 
.

All indications suggest that you should go through and adjust ALL shoes closer to the drum before bleeding brakes. By adjusting the shoes closer to the drum, you should substantially decrease that 4" distance that the pedal is going down initially.

Coop

.
 
If the wheel cylinders to big or the M/c is to small the displacement s a issue ,M/c is 1"1/8 ? from memory ,
 
The master & wheel cylinders were ordered for a 1939. I don't know the sizes as no one puts that on the parts, at least not the ones I bought. They all came from an early V8 supplier. I'm pretty sure they are 1 1/8" though on the rears & 1 1/4" on the fronts. Later I read that the fronts could use 1 3/8" wheel cylinders.
 
Front cylinders can be a stepped type 1.1/4 front and 1" at the rear of it .Rear Cylinders can be stepped 1"1/8 and 1" at rear of it .
 
I believe those are the sizes Ted. I just watched another video & wondered what you thought. I have been putting the master cap on finger tight after adding fluid while bleeding. Is that a bad idea The video said to loosen the cap but not leave it off as fluid will splash out. Maybe the cap being finger tight is my problem.
 
I believe those are the sizes Ted. I just watched another video & wondered what you thought. I have been putting the master cap on finger tight after adding fluid while bleeding. Is that a bad idea The video said to loosen the cap but not leave it off as fluid will splash out. Maybe the cap being finger tight is my problem.


Cap being finger-tight AIN'T your problem.

Coop

.
 
I recommend adjusting the brakes if you haven't done that. I did that on my 39 that I just redid the brakes on and I was able to bleed pretty easily. I pumped until air quit coming from the bleeder and then I did them all again just to make sure.
 
I hesitate to do a major adjustment as the brakes were good before the work I did. According to the instructions in the service book, it says to apply 25 -35 pounds of pressure with a brake pedal jack. What do other people use? I don't have that tool.
 
Don’t worry about not having a Pedal Jack.
Back the Brakes off all the way .
Follow the Major Adjustment procedure..
Get a good Pedal .

Carefully drive it and then do a Minor Adjustment.
Twice

Good Luck , Stretch
 
I hesitate to do a major adjustment as the brakes were good before the work I did.

ADJUST THE SHOES! ! !

Think about it .... ! As that pedal is going down that initial FOUR inches, it is moving all those shoes through all that EXTRA air space you have between shoes and drum. ADJUST THE SHOES! ! !


Coop

.
 
What the heck is a brake pedal jack? never heard of it. I assume it would replicate me cutting a stick to the proper length to squeeze between the seat and the pedal to bleed by myself. When the body is off, a bungi cord works great too
 
I use a pressure bleed system and it works very well. I had to make an adaptor for the Ford master cylinder but it works great every time. Mart.
 
The brake pedal and clutch pedal return spring are identical 5.4" long 91A-7523. Adjust the brake cams so the brakes have a heavy drag before bleeding. After bleeding then just readjust for a very slight drag.
 

Attachments

  • Spring 39 brake & clutch pedal 91A-7523  5.40 OAL.jpg
    Spring 39 brake & clutch pedal 91A-7523 5.40 OAL.jpg
    68 KB · Views: 4
  • Spring 39 brake & clutch pedal.jpg
    Spring 39 brake & clutch pedal.jpg
    27 KB · Views: 3
Back
Top