Topic: 47 brakes not stopping

bobb    -- 11-22-2023 @ 7:26 AM
  I cannot lock up brakes to come to a stop. I recently installed new master cylinder (bench bled), new wheel cylinders, new hoses. I both vacuum and pedal-bled brakes. I set adjusters just before drag. When coming to a stop I coast to a stop no matter how hard I stand on pedal. if something happened unexpectedly in front of me, I would hit it. I've re-bled brakes 3 times, no air or leaks. 1947 Mercury Coupe Sedan. Drums front and rear. I have no e-brakes hooked up. I'm obtaining all e- brake parts that were missing from my rear wheels when I purchased car. I fail to see how the e-brake issue could contribute to the problem???? Any suggestions would be appreciated. Bob

ps. I have driven old cars most of my life (82) and am use to none power brakes.

carcrazy    -- 11-22-2023 @ 12:40 PM
  One way to adjust the brakes to get them to stop the car securely is to perform the following steps:
1. Adjust the brakes so they totally lock up the drum to where you can't turn it at all when pulling on the wheel with all your might using your hands
2. Loosen up the adjusters to where the brakes still have just a little drag
3. Make sure all of the brakes have about the same amount of drag so the car doesn't pull to either side when the brakes are applied.
4. Test drive the vehicle to make sure you have a high pedal and and that each brake is providing an even amount of the braking.

trjford8    -- 11-25-2023 @ 8:35 AM
  Since you put in a new master cylinder did you adjust the push rod from the pedal to the master cylinder?

37RAGTOPMAN    -- 11-25-2023 @ 12:27 PM
did you use moulded rivit on brake lining or glued on brake lining,
are the metal shoes original FORD ? or Aftermarket ?
where did you get them, did you compare them to the ones you took off ? EXACTLY THE SAME SIZE ?
the have to , for the brakes to work correctly, [FULL CONTACT WITH THE DRUMS ]
some of the after market shoes do not give you a high pedal, are not the right size, this is what I have heard,
also disconnect your hand brake cables and adjust the rear brakes, then attach your hand brake cables,
if you have to adjust them, then they were out of ajustment, and were the rear brakes had no FULL CONTACT with the drums,
you say you have new drums, were did you get them. they might have a coating on them to prevent rust,
did you clean them with brake cleaner before using, them,?
hope this helps 37Ragtopman, MAINE

bobb    -- 11-26-2023 @ 10:04 AM

I mis-led you when I said "Drums both front and rear" I was clarifying that I do not have disc on front. I did not change out shoes nor drums.
The riveted existing shoes all had rivets that were about .100 recessed. and all rivets were uniform. Linings were within .o10 top to bottom.
This all led me to believe shoes were riding properly within drums.
I have car up on rack now and i'm gonna take above mentioned suggestions to adjust my master cylinder push rod and also re-adjust my brakes allowing drag. I had adjusted them with no drag.
Thank you all for the advise and suggestions. Bob

TomO    -- 11-28-2023 @ 6:54 AM
  Bobb, Is your brake pedal hard? How much travel do you have before the pedal stops moving? Did you have thi problem before you replaced the parts?

The answers to these questions will hel us diagnose your problem.


carcrazy    -- 12-02-2023 @ 9:50 AM
  What is the I.D. of your brake drums? They may have been turned to too large of a diameter sometime in the past. If the I.D.s are too large, you will have to install thicker linings on the shoes to get functioning brakes.

51woodie    -- 04-13-2024 @ 7:14 AM
  Bobb. Is this car "new" to you? The description you gave of the linings indicates they are in good order, but do the shoes have full contact on all the linings? Here is a picture that shows what I experienced with poor contact and lousy brakes, until I arced all the linings.

37RAGTOPMAN    -- 05-21-2024 @ 6:07 AM
  47 brakes not stopping ?
describing exactly what you did to the car, makes it easier helping you
photo's help., and
what you said in your description you have DISC brakes in the front, ?
on the rear brakes, what kind of lining did you use, soft, or original hard lining,?
if you are using the 39 - 48 master cylinder it will not work,or not correctly
the disc brake require a certain amount of fluid and pressure,
you need to use a master cylinder made for disc brakes. and might have add a valve in the system.
I would put the car ona lift and have someone apply the brakes and see if any of the wheels lock up try turning by hand,
and how much pedal pressure it needed,
get back to us with results, Thanks
hope this helps 37Ragtopman ,MAINE

sarahcecelia    -- 06-10-2024 @ 4:41 AM
  I found out years ago that new brake drums need to be 'Trued" on the brake drum lathe before installing them.

I put a brand new set on my '68 Ford Falcon and had the same problem you are having; I went back to where I ordered them from; he said they get knocked around during shipping and aren't;TRUE.

I took them to NAPA and they "Trued them on the drum lathe." Problem SOLVED!!!

Regards, Steve Lee

ford38v8    -- 06-10-2024 @ 9:51 PM
  bobb, if you are using silicone brake fluid, bleeding must be done very slow and steady to avoid air bubble inclusion, which means soft pedal.
Centering the shoes can be made easier by snugging to drag which can indicate improved centering when drag decreases, then repeating till re-centering makes no change in drag.
(I hope this babbling is understandable?)
The arcing of the shoes is important also, but this can also be done on the car on a back road by repeated braking, just don't get the brakes hot in doing so.


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