Front Rims Hot After Brake Repair

[Dragonfly14]

I bought my 79 Bronco Ranger XLT about 15 years ago for 5k. Still running strong and proud today w/ a 351. I had a friend of the family put new brakes and calipers on the front end, now the rims get super hot if i drive it more than a couple of miles. Any idea on what went wrong and how do i fix it?

 

[miesk5]

yo D,

WELCOME!

We had a 78 351M 4 speed, but sold it in 96 to buy the 96.

still miss it!

Any noise from wheel/brake area?

Could be caused by a combination of the brake caliper seizing & the brake hose collapsing internally as a result.

what happens is that the piston seizes, resulting in the brakes overheating. the overheating causes the brake fluid inside the caliper and brake hose attached to it to boil. This boiling of the fluid softens the rubber parts of the caliper and inner rubber of the brake hose, causing them to collapse. when this happens, the fluid cannot return to the master cylinder when you let off the brake pedal and the brake remains engaged.

Was caliper bled?

Were wheel bearings cleaned & lubed?

try spinning the wheel by hand, if it moves with a slight drag, this is normal, if it is hard to turn, you may need work on the cylinder, it may not be allowing the pad to adequately return to it’s proper position

Was proportioning valve replaced or worked on?

 

[Dragonfly14]

they were bled. I did find out that he didn't clean the rotors off before installing the new parts. There's no noise coming from the front end. The guy came highly recommended, but i don't believe I will have him to even air up my basketball! I'll spin the front wheel and check that way. Thanks for all the info

 

[Seabronc]

Welcome!

 

[miesk5]

yo D,

This is from Chilton

If the rotor is deeply scarred or has shallow cracks, it may be refinished on a disc brake rotor lathe. Also, if the lateral run-out exceeds 0.010 in. (0.25mm) within a 6 in. (152mm) radius when measured with a dial indicator, with the stylus 1 in. (25mm) in from the edge of the rotor, the rotor should be refinished or replaced.

A maximum of 0.020 in. (0.5mm) of material may be removed equally from each friction surface of the rotor. If the damage cannot be corrected when the rotor has been machined to the minimum thickness shown on the rotor, it should be replaced.

The finished braking surfaces of the rotor must be parallel within 0.007 in. (0.18mm) for an integral hub and rotor and 0.0010 (0.0254 mm) for a separate hub and rotor and lateral run-out must not be more than 0.003 in. (0.076mm) on the inboard surface in a 5 in. (127mm) radius.

 

[Seabronc]

I'm thinking that the calipers are sticking.  Did he clean the pins and re-lubricate them?  Also, was the hub removed and reinstalled?  Possible improperly tightened hub nuts

Good luck,

>-

 

[68Mercury250Ranger]

that sound right, guy pushed the calipers back to fit in the new pads and now they are sticking after an application.  

good luck.

 

[Rons beast]

Hey D-fly welcome.

You said that the guy put new calipers on right? Good possibility that he used a vice-grip to crimp the brake hose. Now when the brakes are applied the pressure to the calipers is  return restricted.  Never pinch off flexible brake hose...especially on a vehicle as old as yours.

If the wheels are binding, crack the fitting attaching the hose to the caliper. If pressure is released, you need new hoses. Always replace both sides.

Good Luck.

 

[Seabronc]

Ditto on Ron's comment.  I forgot about that possibility, had it happen to me once on old lines that broke down internally and created a valve that restricted the return flow of fluid when the brakes were released.

Good luck,

>-

 

[Bully Bob]

Not cleaning the rotors would not have caused this. In most cases there's no need to clean them

unless they have dirty/greasy paw prints on them.

However, turning them is a good idea & not expensive.

Pushing the pads back in order to fit over the rotors is normal. It has to be done.

Were you driving it regularly B/4 the brake job..?  What brought about the front brake re-build..?

Were there stopping issues or was it a visual inspection..?

Along with whats mentioned above,

Maybe while disturbing things, old, dirty brake fluid got into the pistons.

Just moving the hoses may have brought about their last days.

Worst case.., would be some bad calipers off the shelf.  Where were they purchased.?

Are they new or re-built..?

Don't be to quick to blame.., "Murphys-Law" is always lurking there somewhere... >< <'>

 

[Dragonfly14]

No, he did not clean or re-grease anything. He also did not know that the truck had to be running in order to bleed the brakes. The motor had just been re-built, the brakes actually failed on the way home. So the truck was parked for almost a year. I was an OTR truck driver, that's why it sat. It was started up 3 or 4 times a month but never moved. The brake and calipers were done, truck was test drove. Everything seemed to be ok. Driving from northern TN to Texas was when the rims started heating up. It's been parked since.

 

[Bully Bob]

"He also did not know that the truck had to be running in order to bleed the brakes"

Never heard of this but, anything is possible.

On an older vehicle.., (maybe the br. fluid has never been changed) that's been sitting for

long periods, it should be "reverse" flushed with new fluid. This pushes all the junk back

& out of the lines. Most shops have this capability.

I forgot.., we didn't mention the Master cylinder. It could be plugged/dirty/need re-setting.

And as M5 said.., there could be an issue with the proportioning valve.

That & the master cyl. are easy/inexpensive fixes.

"the brakes actually failed on the way home."

Hmmm.., this is suspecious.  "failed" in what way...? Noisy, pulled right/left, wouldn't stop,

hard pedal, no pedal.....?

 

[68Mercury250Ranger]

vehicle running to bleed brakes?  maybe if you have hydromax, but the electric backup shoul dwork there for you.  

you may have a brake booster sticking,   IIRC  the bronco has a lever mechanism behind the booster diaghram.  bad for seizing up if you have been offroading or winter driving or............siiting around not being used. 

have fun.

 

[Broncolife]

I bought my 79 Bronco Ranger XLT about 15 years ago for 5k. Still running strong and proud today w/ a 351. I had a friend of the family put new brakes and calipers on the front end, now the rims get super hot if i drive it more than a couple of miles. Any idea on what went wrong and how do i fix it?View attachment 13912

I just bought a 1979 bronco I was 3 hours away from home the calipers was sticking and starting smoking I took it to the shop to get it checked it literally cooked my wheel bearings.

 

[Skitter302]

ouch. I've even had my master cylinder go bad and keep pressure on my fronts and cause the pads to smell hot.