spongy fading brakes Problem found!!!!!!!!

[ContryboyFE]

my brakes keep loosing pressure AND fluid (slowly). i just replaced both front wheel cyls, blead the lines TWICE, and it still keeps fading. any suggestions?

[two-bit]

I am going to make the assumption that this is on a four drum brake truck.
If so: here you go.
Spongy/fading brakes on a four drum system with new parts is usually due to improperly adjusted shoes.
Usually.
If you pump the the brake pedal three times, does the pedal get stiffer? or stay the same?
If it gets stiffer its either because of air or improperly adj. drum brakes. If it stays the same its usually a bad master cyl.

When adj. front drums I prefer to run as much "drag" as i can. Turning out the adj as far as you can and then putting the drum on is not a good enough adj. for front drums. I usually lay down on the ground with the truck blocked up with the tires on it. I then spin the front tire with one hand. Keeping track how far the tire rotates when i do it.
Then i turn in the adj. ( rotating the tire a little), until i start to hear the shoes "drag" on the drum. Then i spin the tire again, note the rotation, and tighten the adj. some more. I do this until the tire will rotate about 1/2 to 3/4 of a turn and then stop.
Then go to the other side, do the same thing.
Since our trucks are fairly light in the rear when empty, i don't run the rears as tight. maybe the equivalent of 1 1/2 turns. If you set the rears as tight as the fronts the rear brakes will be very sticky, and lock-up easily.
Off the stands and off on your first test drive. Grab a hold of the wheel VERY firmly. Apply brakes. Be ready for the truck to pull right or left. If it does, go to the opposite front tire and tighten your adj. two or three clicks.
Then try this hail mary routine again.
Still pulls, repeat above. If not, you have evened out the front brake pressure between the wheels. It can take some time, but i think its really important to do this because in a hard brake situation you don't want to have to fight the steering wheel too!!!

Your brake pedal shouldn't have much travel to it at all. Applying the same amount of pressure, the fronts should lock-up on gravel but not on concrete. (unless you REALLY jump on them)

Some people will argue that i run my front drums to tight. That it will cause my shoes to wear out prematurely, and that they will "lock-up" easier that way. All those things may be true. However, i would much rather have a tight brake pedal and replace shoes once a year, then hit something because i had to pump twice before i had good brakes.
There will probably be some other really good ideas from other members here that i don't do, or know about.
This is just how i set mine up.

If you have front discs with rear drums.... You better hope someone else chimes in. Drum/Drum is my specialty, not drum/disc

Good luck
Two-bit

[fordman]

if your losing fluid it has to be going some place. i have the same problem with my 67. if it sits too long it loses all of the fluid out of the master and i have no brakes. i don't have a booster and i can't find any leaks. but the crossmemeber is greasy. so it could be coming from that area. i haven't had time to look at it lately. but when you find your leak you will find the problem. check the bottom backside of the tires the next morning after you push on the brake the night before. if you see wetness the fluid is getting otu of the wheel cylinder area. other leaks will form wet looking areas where they leak at. like on the lines or frame.

[ContryboyFE]

the frount wheel cyl. were leaking ALOT. when i fixed them the wet spots were gone behind the front tires. i'll check out the adjusters asap but the leak still worries me. any other suggestions or fixes (even better) PLEASE post

[19FORD67]

Im like Fordman, after my '67 sat for awhile I'd always have to add fluid. Because I had a leak, and as I'm finding out, I have more than one leak ( it is, after all, over 40 years old) eventually it didnt matter how much fluid I would add because now,
my brakes are full of air. I'd say find out where the fluid is going first. If you have a leak, everytime you let off the brakes
it will suck some air back in, causing them to gradually get worse and worse. I'm not pretending to know what I'm talking about though this is just a no0b perspective. Good luck!

[ContryboyFE]

Im like Fordman, after my '67 sat for awhile I'd always have to add fluid. Because I had a leak, and as I'm finding out, I have more than one leak ( it is, after all, over 40 years old) eventually it didnt matter how much fluid I would add because now,
my brakes are full of air. I'd say find out where the fluid is going first. If you have a leak, everytime you let off the brakes
it will suck some air back in, causing them to gradually get worse and worse. I'm not pretending to know what I'm talking about though this is just a no0b perspective. Good luck!

makes sense to me. this all started after it sat about 10 months. im looking but nothing yet
mines gona be 41 this summer. ive had it since i was 17 and learned as ive gone. fun though.

[thebannister8]

check your back wheel cycliners...if front and rear systems aren't completely separate then bleed all 4 anytime 1 or more is changed...check your master cyclinder ...and are you bleeding by pumping more than once between bleeds ........................also spongy is not the result of improperly adjusted brakes ..... after the shoes are seated and when freely spinning the tire on jacks find the point where they just begin to rub and back off the adjuster 2-4 clicks ..backed off 1 1/2 turns will increase the chances of accidental lockup in heavy breaking greatly

[ContryboyFE]

how do check the master cyclinder?

[thebannister8]

just another tidbit of info...you mentioned that the front wheel cylinders were leaking alot....if they leaked on the brakes.....toss the brakes...

[ContryboyFE]

just another tidbit of info...you mentioned that the front wheel cylinders were leaking alot....if they leaked on the brakes.....toss the brakes...

my pads just FAILED on me. i didnt check them and now i know why you said that. i thought my barings were wining so i bought some greese and pulled the drum off only to find the pad had graneded into dozens of pices. that'll teach me not to listen

[ContryboyFE]

i also pulled back my carpet in the cab and found break fluid on the firewall now i know what has to be done.

thanks to all thoughs who helped and gave suggestions.

ben

[Alvin in AZ]

New noises are -bad-! ;)
Check into them right away and find out what's wrong. :)
...or you could do like most 'mericans and drive it 'til it quits somewhere.
...and the "new noise" takes some big priced items with it. :/

My pickup has never broke down and left me stranded anywhere, ever. :)
I special ordered it late Nov '74.
The 1975 Ford Truck Shop Manuals arrived first. LOL :) $31

Alvin in AZ

[ContryboyFE]

New noises are -bad-!
Check into them right away and find out what's wrong.
...or you could do like most 'mericans and drive it 'til it quits somewhere.
...and the "new noise" takes some big priced items with it. :/

My pickup has never broke down and left me stranded anywhere, ever.
I special ordered it late Nov '74.
The 1975 Ford Truck Shop Manuals arrived first. LOL $31

Alvin in AZ

their have only been two timesi've had to walk away from my 68 on the road and they have both been my falt. my wife thinks im funny b/c i notice little new noises. but its true you must check them out fast and im glad i did and do.

[Banjo]

honestly, that's why in older vehicles, I don't listen to the radio. I can hear and try to get onto problems quicker.

[ContryboyFE]

honestly, that's why in older vehicles, I don't listen to the radio. I can hear and try to get onto problems quicker.

you cant hear it over 40 anyway with duel 18" glass under the cab.