Stuck brakes.

[yewhi]

Good morning all and happy Father’s Day. I‘d like to pick your brain’s regarding a recent issue with my 73’.

yesterday I took the 73’ out to get her a little drive time (Not far 7-8 miles). Upon returning I noticed the subtle but distinct smell of burning brakes but hadn’t really noticed anything dragging. I parked it in the driveway and did other things for about an hour before putting her away. On restart I noticed the brake pedal had hardened and that the brakes were pretty much locked up. Jacked up front end and sure enough both wheels were locked solid.i covered her for the night and this morning tried again. Brakes were looser but not completely back to normal.

background on Bronco.

73’ with 76/77 front end, D44, Ford disc brakes up front. Drums in back. Master cylinder is stock without a booster, no proportioning value. I’ve owned the Bronco since 98’ and this is how I bought her. Except for routine maintenance I haven’t changed out any parts. The thanks in advance! doesn’t get out too much lately (once every month at best).

question I have is this. In addition to an obvious brake fluid flush, does it sound like the master cylinder is sticking and needs replacing? If so would it be worth while upgrading to something like a wilwood master? Apologies, for my ignoranc, I’ve just never experienced exactly this issue before.

 

[Yeller]

Calipers are probably sticking, more likely than the master cylinder since you have not worked on or changed any of that. Replace the calipers first. If you use a turkey baster to remove the fluid from the master cylinder and refill with fresh fluid. you will flush the rest of the old fluid bleeding the brakes.

 

[ksagis]

Good morning all and happy Father’s Day. I‘d like to pick your brain’s regarding a recent issue with my 73’.

yesterday I took the 73’ out to get her a little drive time (Not far 7-8 miles). Upon returning I noticed the subtle but distinct smell of burning brakes but hadn’t really noticed anything dragging. I parked it in the driveway and did other things for about an hour before putting her away. On restart I noticed the brake pedal had hardened and that the brakes were pretty much locked up. Jacked up front end and sure enough both wheels were locked solid.i covered her for the night and this morning tried again. Brakes were looser but not completely back to normal.

background on Bronco.

73’ with 76/77 front end, D44, Ford disc brakes up front. Drums in back. Master cylinder is stock without a booster, no proportioning value. I’ve owned the Bronco since 98’ and this is how I bought her. Except for routine maintenance I haven’t changed out any parts. The thanks in advance! doesn’t get out too much lately (once every month at best).

question I have is this. In addition to an obvious brake fluid flush, does it sound like the master cylinder is sticking and needs replacing? If so would it be worth while upgrading to something like a wilwood master? Apologies, for my ignoranc, I’ve just never experienced exactly this issue before.

I've rebuilt calipers before with good luck, don't know if you can get replacement seals and pistons, might be worth a shot if replacement calipers are pricey.

 

[Slowleak]

Open the bleeder valves on the calipers to see if the pressure releases and the brakes free up. That will tell you if the calipers are stuck.

 

[SteveL]

If both calipers were sticking take a peek in the engine compartment and make sure you don't have a pinched line from mc to frame or from frame to the axle. If you have a kinked or clogged line it won't allow the fluid to flow back causing things to heat up and stick.

 

[Yeller]

Deteriorating/failing brake hoses will do it too. I agree odd it is both of them.

 

[Shimmy]

agree with what's been mentioned above. Rockauto has replacement calipers and/or rebuild kits.

as part of your routine maintenance, how often are you doing brake fluid flushes?

 

[Steve83]

73’ with 76/77 front end, D44, Ford disc brakes up front. Drums in back. Master cylinder is stock without a booster, no proportioning value. I’ve owned the Bronco since 98... ... doesn’t get out too much lately (once every month at best).

You should put ALL its details into your signature so you don't have to re-type that & everything else each time you ask a question.

...routine maintenance...

Which is what, exactly?

...an obvious brake fluid flush...

That's not really obvious. Changing the fluid is part of normal maintenance - when was the last time you did it? But it's not a repair for anything, and is not indicated by this symptom.

does it sound like the master cylinder is sticking and needs replacing?

No.

...upgrading to something like a wilwood master?

Wilwood is not higher grade than Ford.

BTW
An apostrophe after a number means feet. Before means you've left out some of the digits, like '73 instead of 1973.