The Ford Barn

wspiker · 12-17-2011, 08:54 PM

I just completed replacing the brake system on my '40 Ford. I replaced the master cylinder, wheel cylinders, turn the drums and re-lined the shoes. I bleed the system and adjusted brakes per instructions. On my first drive with the car, after the first five miles, the brake system expanded to where I had no free brake pedal and as I would come to a signal light, the car would 'brake it self'. After the system cooled down, the system was 'normal' again. So, I backed off the adjustments (completely) and still had normal brake pedal. I took the car for my next ride and the SAME thing happened. When I got to my drive way, I saw that the system had expanded to the point the brake light was on and there was no free pedal! Does anyone have an explanation for this and what I need to do to FIX it, please?

paul2748 · 12-17-2011, 09:19 PM

A possibility is the flex hoses. They can go bad on the inside with no indication on the outside. Replace if they are old.

Let us know what you find.

Quote:

Originally Posted by wspiker

I just completed replacing the brake system on my '40 Ford. I replaced the master cylinder, wheel cylinders, turn the drums and re-lined the shoes. I bleed the system and adjusted brakes per instructions. On my first drive with the car, after the first five miles, the brake system expanded to where I had no free brake pedal and as I would come to a signal light, the car would 'brake it self'. After the system cooled down, the system was 'normal' again. So, I backed off the adjustments (completely) and still had normal brake pedal. I took the car for my next ride and the SAME thing happened. When I got to my drive way, I saw that the system had expanded to the point the brake light was on and there was no free pedal! Does anyone have an explanation for this and what I need to do to FIX it, please?

johnny · 12-17-2011, 09:25 PM

you need to adjust the rod going into the mastercylinderit needs more free play.John.

Vergil · 12-17-2011, 09:29 PM

Shorten the master cylinder rod until you have a little free play between the rod end and master cylinder piston seat (1/16"- 1/8"). The master cylinder piston must come all the way back when the brake pedal is all the way up to let the brake fluid back into the master cylinder. If the fluid can't return to the master cylinder this will happen. If you have free play now it may be a bad cylinder repair kit.

19Fordy · 12-17-2011, 10:28 PM

This is just a stab in the dark, but is your emergency brake properly adjusted?

Kahuna · 12-17-2011, 10:42 PM

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Johnny and Vergil got it. Fix the rod

wspiker · 12-19-2011, 07:37 PM

When you say 'shorten the rod', does that mean I free the locking nut to the brass bolt on the piston rod and adjust so there is less thread showing? I will be accomplishing tomorrow and, of course, will soon find out. But, this would help me to know 'from the get go'.

Thanks,

Daryl

johnny · 12-19-2011, 08:57 PM

Yes that is the idea

jkeesey · 12-19-2011, 09:20 PM

The rod is actually a plated steel not brass so you don't have to worry about over torque on the jam nut. I had the exact same problem on a 39 and adjusting the master operating rod was the ticket.

nostalgia59 · 12-20-2011, 08:23 AM

Another problem is moisture in the brake system.

Flatout · 12-20-2011, 02:05 PM

I've had the same thing happen to me a few times. The problem was in the master cylinder. There's a tiny hole to let fluid back into the resivoir. That was plugged. fluid would go out the lines to the wheels, but could not bleed back into the master cylinder, but couldn't get back, or couldn't get back in fast enough and soon the wheels couldn't turn because of draging.
I just bought a 40 myself, and am getting ready to go through the brakes.
Sdtan

wspiker · 12-20-2011, 06:46 PM

Yes, I checked that, thanks. Hey, I see you are close to where I purchased this car in September. I bought it in Lake Park, FL; it was restored ten years ago, and own, by Chuck Wooten. Do you know him? He was an Early Ford member of the West Palm Beach RG.

wspiker · 12-21-2011, 08:45 PM

I GOT IT! Thank you all. What a difference a small adjustment makes. It feels so good to now drive down the street and all the tires are 'free wheelin'. Thanks again. Now I can move on to the next 'crisis', i.e. the generator is not generating! But, that is a much easier one for me. :-)

Daryl Spiker
Sacramento, CA

Mart · 12-22-2011, 06:35 AM

Well done!

12-17-2011, 08:54 PM	#1
wspiker Senior Member Join Date: Feb 2011 Location: Sacramento, CA Posts: 190	1940 Ford Brakes I just completed replacing the brake system on my '40 Ford. I replaced the master cylinder, wheel cylinders, turn the drums and re-lined the shoes. I bleed the system and adjusted brakes per instructions. On my first drive with the car, after the first five miles, the brake system expanded to where I had no free brake pedal and as I would come to a signal light, the car would 'brake it self'. After the system cooled down, the system was 'normal' again. So, I backed off the adjustments (completely) and still had normal brake pedal. I took the car for my next ride and the SAME thing happened. When I got to my drive way, I saw that the system had expanded to the point the brake light was on and there was no free pedal! Does anyone have an explanation for this and what I need to do to FIX it, please?

12-17-2011, 09:25 PM	#3
johnny Senior Member Join Date: May 2010 Location: London On, Can. Posts: 377	Re: 1940 Ford Brakes you need to adjust the rod going into the mastercylinderit needs more free play.John.

12-17-2011, 09:29 PM	#4
Vergil Senior Member Join Date: May 2010 Location: Tehachapi, CA Posts: 361	Re: 1940 Ford Brakes Shorten the master cylinder rod until you have a little free play between the rod end and master cylinder piston seat (1/16"- 1/8"). The master cylinder piston must come all the way back when the brake pedal is all the way up to let the brake fluid back into the master cylinder. If the fluid can't return to the master cylinder this will happen. If you have free play now it may be a bad cylinder repair kit. __________________ Bigger fonts to aid in reading

12-17-2011, 10:28 PM	#5
19Fordy Senior Member Join Date: May 2010 Location: Coral Springs FL Posts: 10,945	Re: 1940 Ford Brakes This is just a stab in the dark, but is your emergency brake properly adjusted?

12-17-2011, 10:42 PM	#6
Kahuna Senior Member Join Date: May 2010 Location: NorCal Posts: 2,617	Re: 1940 Ford Brakes Sponsored Links (Register now to hide all advertisements) Johnny and Vergil got it. Fix the rod

12-19-2011, 07:37 PM	#7
wspiker Senior Member Join Date: Feb 2011 Location: Sacramento, CA Posts: 190	Re: 1940 Ford Brakes When you say 'shorten the rod', does that mean I free the locking nut to the brass bolt on the piston rod and adjust so there is less thread showing? I will be accomplishing tomorrow and, of course, will soon find out. But, this would help me to know 'from the get go'. Thanks, Daryl

12-19-2011, 08:57 PM	#8
johnny Senior Member Join Date: May 2010 Location: London On, Can. Posts: 377	Re: 1940 Ford Brakes Yes that is the idea

12-19-2011, 09:20 PM	#9
jkeesey Senior Member Join Date: Apr 2011 Location: Glenmoore Pa Posts: 1,644	Re: 1940 Ford Brakes The rod is actually a plated steel not brass so you don't have to worry about over torque on the jam nut. I had the exact same problem on a 39 and adjusting the master operating rod was the ticket.

12-20-2011, 08:23 AM	#10
nostalgia59 Member Join Date: May 2010 Location: Torrance Ca. Posts: 51	Re: 1940 Ford Brakes Another problem is moisture in the brake system.

12-20-2011, 02:05 PM	#11
Flatout Senior Member Join Date: May 2010 Location: Damascus Oregon Posts: 160	Re: 1940 Ford Brakes I've had the same thing happen to me a few times. The problem was in the master cylinder. There's a tiny hole to let fluid back into the resivoir. That was plugged. fluid would go out the lines to the wheels, but could not bleed back into the master cylinder, but couldn't get back, or couldn't get back in fast enough and soon the wheels couldn't turn because of draging. I just bought a 40 myself, and am getting ready to go through the brakes. Sdtan

12-20-2011, 06:46 PM	#12
wspiker Senior Member Join Date: Feb 2011 Location: Sacramento, CA Posts: 190	Re: 1940 Ford Brakes Yes, I checked that, thanks. Hey, I see you are close to where I purchased this car in September. I bought it in Lake Park, FL; it was restored ten years ago, and own, by Chuck Wooten. Do you know him? He was an Early Ford member of the West Palm Beach RG.

12-21-2011, 08:45 PM	#13
wspiker Senior Member Join Date: Feb 2011 Location: Sacramento, CA Posts: 190	Re: 1940 Ford Brakes I GOT IT! Thank you all. What a difference a small adjustment makes. It feels so good to now drive down the street and all the tires are 'free wheelin'. Thanks again. Now I can move on to the next 'crisis', i.e. the generator is not generating! But, that is a much easier one for me. :-) Daryl Spiker Sacramento, CA

12-22-2011, 06:35 AM	#14
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,754	Re: 1940 Ford Brakes Well done!