hello all
truck in question is a 1974 ford f100 with manual brakes today drove fine and stopped like always for about 4 miles, then i started to notice i had to push on gas pedal more to make it go. i was struggling to stay at 40mph, then the rear of my truck started bouncing up and down not much but i felt it and as i was pulling over to the side of the road i noticed my pedal was alot harder than usual to push. both front wheels were very hot to the touch and smoke coming from rear drums both sides.
normally i would say emergency/parking brake was on which would have caused the lack of power but my truck hasnt had a parking brake for about 2yrs, parking brake pedal under dash is gone but cables are still hooked up in drums. so far i checked to see if i was getting fluid to front calipers which i am. today i also removed both calipers, the driver side seemed froze when i took a c-clamp to it so i just went ahead and replaced both front calipers. i bled both with the pump, hold and release air from bleeder method. after i was finished pedal felt good so i drove it again, then just like before about 4 miles out started loosing speed and brake pedal very hard when attempting to stop. when i got back home i removed the master cylinder praying this was it, i pushed down on the plunger plenty of fluid shot out and so now i assume please correct me if im wrong if fluid sprays out of the master cylinder shouldn't that mean its good? would the proportioning valve cause the above symptoms? have any of you had the above and what was the problem?
thank you for any help or info you provide

i apologize for all my bad sentence grammar misplaced periods, commas and run-on sentences i fell asleep alot in class when i was a kid so please forgive me

 

Has anybody added fluid to the brake reservoir recently? I had the happen on a '79 E-250 one time. My ex-wife let a kid working at a service station add power steering fluid. He put it in the brake fluid reservoir. Every piece of rubber in the brake system had to be replaced. It did the same thing you are describing, except my idiot ex drove it twenty miles home with the brakes dragging.

 

On the second go-around did the front discs still seem to be locking up or was it just the rear drums?
If it's the rear only this time you might look at the flex hose that connects the rear brake lines to the frame. Soft hoses can look okay outside but collapse internally and keep fluid from flowing in one direction making the brakes not release.
As for the master, it could still be bad.

 

That's another good possibilty, especially if the fronts are still dragging.
(Note: at least she's your "ex")

 

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lol, no i am the only idiot that adds fluid and i used brakefluid, cant remember what DOT i use i think it was 3

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the front brakes was still locking up. this was the reason i decided to remove the master cylinder but after being discouraged seeing it gush fluid i figured id just ask you guys and gals. a reman master is not to expensive ill just pick one tommorrow and let you know,

thank you both for your time

 

If it's something in common with the front and rear brakes I would lean towards the master cylinder. Good luck.

 

Is the brake fluid still...fluid? What I mean is, when power steering fluid was put in mine, it turned to a gel. I've also been told that mixing DOT 3 and DOT 5 silicone fluid will have the same result. If the fluid is still 'runny', or thin as it should be, something is not letting the fluid return to the reservoir after you let off the brakes.

 

This isn't very scientific but you could reinstall the master cylinder, take a flare nut wrench with you, drive it untill the problem reappears, pull over and "crack" the two brake lines at the M/C connection. If it is the M/C then that should relieve the pressure and the brakes release. Tighten the lines, get back home and replace the cylinder.

 

ok because the georgia clay absorbs water like a sponge i couldnt get the master cylinder on yesterday but today i was able to get it on and bleed all four brakes. i drove it and everything seems perfect. before i had this little jump when i put the transmission in gear or when i would make a complete stop, but this is now gone as well. so thank you guys or gals i appreciate all your help here with me and all the other advice you provide here at FTE, will rep you all. thanks again - gary