When is a brake dragging?

[CobyRupert]

I have a Ford F-250. Front passenger side is making a scraping noise, almost like pads are gone. But constantly, even when not braking. Hubs are unlocked.
I look, pads are good.
Ok, must be sticky caliper.
I can turn the tire “fine”. Turn hub fine with tire off.
Press brake pedal and release, tire still turns “fine”.
But what is “fine”?

It doesn’t spin like a roulette wheel. If I give it a “1 grunt” heave and let go, tire turns about 1/4 to 1/3 of a rotation before stopping.
Is that sticking or would you say normal?

I also notice my rims are getting older and flakes of metal/paint seem to be chipping. Could that be getting between pads and disk and making scraping sound? Constantly?
Cleaned it up and will take it for a drive and get a infrared thermostat to test results.

 

[Rebeldad1]

When was your last brake check? How low or what percent of your brake pads are left?

More than likely its time to replace them if you dont know.

Disc pads have a indicator tab built in. Its purpose is to give you a warning when the amount left is minimal. its a metal tab ment to drag on the rotor and make noise. They arnt rocket science so they can make noise from arount 30% left down to nothing at all. Sometimes they dont work and the first squeal you hear is metal to metal with the rotor.

Also metal flakes can come off a wheel and embed in the friction material causing the same result.

If you dont know check them right away. The next time you use your brakes it could be interesting.

 

[Rebeldad1]

By the way they can "look" fine. You need to pull the pads out and look...

 

[newbury]

<Snip>
It doesn稚 spin like a roulette wheel. If I give it a ? grunt heave and let go, tire turns about 1/4 to 1/3 of a rotation before stopping.
Is that sticking or would you say normal?
<snip>

1/4 turn? sounds almost locked up.

Get if off and look at it.

 

[Diggin It]

But what is “fine”?

It doesn’t spin like a roulette wheel. If I give it a “1 grunt” heave and let go, tire turns about 1/4 to 1/3 of a rotation before stopping.
Is that sticking or would you say normal?

That's not 'fine' in my book. Should be at least 1-2 full rotations. Wheel Bearing?

 

[CobyRupert]

You get 1-2 full rotations?
I can see there’s lots of pad left.
I jacked that corner and felt for wheel bearing, but didn’t feel anything.
I took it for a two mile drive. Used brakes 3-4 times.
3 brake disk’s temperatures were in the 150’s degF range.
The right front was in the 170’s F.
So it’s dragging a little. Yet not too bad.
Probably gets worse over more miles as disk heats up and expands.

Time to get it off.

 

[Rebeldad1]

Very few wheels will freewheel more than 1/4 turn with disc brakes on the front. With 4X4 maybe less. a good indicator if its ok is to turn both sides by hand. Should feel the same.Some calipers as they get old the rubber lip the cup sits in becomes less flexable and wont push the cup away. Also if there is any kind of gunk buildup in the caliper cup area it wont release. Really not a issue because as you drive the caliper self centers and helps push on the cup giving it clearance. Even with that they can turn hard freewheeling by hand. 2X4 wheel bearings seated tight or grease old. 4X4 axles and hubs drag.

 

[CobyRupert]

Very few wheels will freewheel more than 1/4 turn with disc brakes on the front. With 4X4 maybe less. a good indicator if its ok is to turn both sides by hand. Should feel the same....

Thanks for the idea. I’ll give it a spin.
Maybe I’ll drive it a few miles farther next time and check temps again.

 

[CobyRupert]

When checking for bearing I got no wobble. But when spinning tire, with hubs unlocked, I detect a faint click when I reversed direction. Was that part of the unlocked hub? I don’t think it was a bearing?

 

[Diggin It]

Thanks for the idea. I’ll give it a spin.
Maybe I’ll drive it a few miles farther next time and check temps again.

::Groans::

 

[Rebeldad1]

some hubs will click. If in doubt pull the hub.

 

[the old grind]

A wheel bearing can feel tight and still run out just enough for the caliper to rub on the rotor and heat it up, but I doubt that this time. Can't spin fast by hand, can we. If there is loud rubbing it's at faster rpm and with weight of the truck flexing it much farther than our arms could. (mere .00x" but real)

Brake hoses can de-laminate internally and show no outward signs of leakage, etc. (inside layer goes first) A bubble of fluid can become trapped between the layers of fiber and rubber under hard braking. This bubble can block the normal flow path and trap a lesser but unwanted pressure in the caliper and cause some brake drag. As the disc and caliper heat up they tighten up when the bubble is 'filled' from the caliper side.

This is a common repair when replacing a caliper didn't cure the similar symptom(s). Clue is usually that the other side caliper works fine. I've even had this happen on my own truck or two, but because I drive so few miles in them. The new-bought truck I sold 2 yrs ago had 38k mi on it and just replaced the OEM tires but was still an '99 underneath, and 'aged' accordingly.

 

[Rebeldad1]

You can speculate all you want but you need to pull the caliper. (2 bolts)
noise stopped? then its in the pads/caliper.

 

[4570Man]

I think it’s dragging. It should turn easier than firm hand pressure. Drive around using the brakes as little as possible and then check that rotor temp compared to the other side. I had a brake dragging hard on one of my trucks and I had to put a caliper on it.

 

[polo1665]

Pretty sure that if it is the wheel bearing, and you can here it grinding, your hub will get very hot as you drive it. You can check that after driving it for a bit.

Of course that might also be true if the breaks are dragging.

 

[ruffdog]

Sometimes pads do not wear evenly and you may be looking at the side that still has material. If the caliper can't float freely, then one pad will wear out quickly. You can pull the wheel and use a large c-clamp on the caliper to push the piston back slightly and recheck your rolling wheel test. As "the old grind" stated above, sometimes old brake hoses get an internal bubble that holds pressure.

 

[CobyRupert]

If it was the brake hose holding pressure, wouldn’t I notice an increased resistance to spinning after I pressed on brakes?

 

[ruffdog]

Normally, yes.

 

[4570Man]

When my truck had a dragging brake pulling the brake hoses off made no difference and fluid was gravity flowing through the hose so it wasn’t bad. At an expense way higher than a hose a new caliper fixed the problem. A simple heat test on the rotors is the easiest trouble shooting you can do.

 

[Clint S]

Does it get worse around slow curves? Does it get better when you you apply the brakes? Does it feel hotter after driving? I have had rust build up and cause a scraping, backing plate scraping. Your best bet has t ok disassemble, clean, inspect and reassemble and go from there