Stinky brakes

[ljspop]

After a 10-12 mile jaunt in the Bronco the other day I noticed my conversion disk brakes were hot and smelling.

History - PO put them on without clearancing the knuckle, so when I go it only one of the pads were engaging on each side. I've since clearanced the knuckle, lubed the pins, and verified no residual valve in the master by sticking a nail in the port. Could there be a residual valve in the distribution block?

It happened once before after I first made the fixes, and I assumed it was just the pads seating themselves. I hadn't taken it on a longer than couple mile ride since, but when I did y'day the brake smell was noticeable.

Thanks for any thoughts.

 

[ryoungbronco]

Make sure the caliper is not frozen. The only way to check is to take the caliper off and check that the piston goes in by using a C-clamp. I had that happen on my Superduty. The disk wound up smoking and there was a terrible smell after only a few mile drive.

 

[broncnaz]

It may take awhile for the pads to seat. It could also be that the rotor is warped due to only 1 pad working before. There are no residueal valves in the prop valve.

 

[ljspop]

Thanks guys. I've felt warped rotors before, I have no pulsing or vibration. Pistons definitely move, I had to push them back to test the knuckle clearancing. I might pull em off and 2x check tho. Hopefully just an extended seating.

 

[Smokeater11]

It is possible that the soft brake hoses are starting to collapse. When this happens the fluid can go into the caliper but can't get back out smoothly causing the pads to drag on the rotor. Once they collapse completely it'll lock the caliper to the rotor and you have to loosen the bleeder valve to release the pressure. Go ahead ask me how I know this;D If it's only smelly on one side that's where I would look once you've ruled out the obvious stuff.

Also make sure you don't have a seal leaking something onto the rotors on the inside.

 

[lonesouth]

I'm gonna vote for more clearancing of the knuckles...

 

[DCrews]

I had that happen to mine. problem was when i replaced master cylinder i didnt ajust rod comeing out of booster . It wouldnt let front calipers disengage. Hope this helps.

 

[ljspop]

Checked the knuckles through their full path - pretty sure that is good.
Brake lines are new(er) steel braided for the lift.

Rod coming out of the booster... hrmm I'll check that.

Thanks guys, great ideas.

 

[DirtDonk]

I was going to ask if you have power too, Since you do, the booster/master/pedal rod length thing would get my vote as well.
Never had the issue myself, but sure have heard about if often enough here!
More often than not, it's a mushy or too stiff pedal that is the clue, but several times there have been reports of dragging brakes.

On another angle, do you know the condition of the wheel bearings? Do you know if they were adjusted properly?
They wouldn't necessarily contribute to a brake overheating issue, but they would definitely cause the assembly to get hot and you could be smelling the grease getting hot.
You may have already verified that it's the brakes only, but I thought I'd throw that in the ring as an alternate.

Paul

 

[ljspop]

I jacked up the front driver wheel and spun it. Some resistance, but not an abnormal amount I think. Pulled the master from the booster and spun it again. No change. I did this all in a hurry before heading to work this morn, now thinking I should pull the master off and measure the length - I looked up what it should be last night. But that test seemed to somewhat rule out the rod length, no. Would I need to have the motor on to really be sure?

Wheel bearings is a good thought too - thanks Paul. I'll check that tonight.

I'm still leaning toward a seating issue since they were set up wrong for a few hundred miles at least. Want to be sure though - thanks for all the input guys.

 

[ljspop]

....stink is definitely brakes tho. hmm Asbestos-ey.