Mechanics

REAR BRAKES HUM

2004 Ford Ranger

Brakes problem
2004 Ford Ranger 6 cyl Two Wheel Drive Automatic 83000 miles

My rear brakes hum when I release the pedal. Sometimes early in the morning after the truck has been sitting for a while the hum is louder and it feels as though they lock up. This happens until the vehicle is war.

Replaced the shoes, spring kit, emergency brake cable and wheel cylinder. What else is left?
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Bababinki
June 9, 2010.




Are you sure the brakes are making the noise and not a bearing?

As far as the brakes grabbing in the AM, what I suggest you try is this. Remove the drums, have them cut, and with sand paper, remove the glaze from the brake shoes. Many times a glaze will build up and the brakes will react that way in the AM and in damp weather. The noise, on the other hand, I feel is something other than a brake problem.

I thought it might be a bearing, but the hum only comes when I release the brake pedal. It's like the shoes stays stuck.
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Tiny
Bababinki
Jun 12, 2010.
That can make sense. If you think about it, when you release the brakes, the directional stress is removed from the bearing.

However, have you checked all the brake springs to make sure none broke and are rubbing the drum?

Ok, replaced the wheel cylinders, brake kit with springs and re-surfaced the drums. This helped for a while, but now the hum is back particularly after the car has been sitting for hours or it is comes when I have driven for about an hour. It only happened when I release the brake pedal and is coming from the right rear. Additionally, in the morning when I first start to drive and I step on the brake harder like coming to a stop sign the rear brakes will momentarily lock and skid. Could the master cylinder be the culprit? There are not a lot of parts to the rear system. Thanks, John

Tiny
Bababinki
Sep 18, 2010.
The only thing left is the wheel bearing. Does the noise change when turning?

No noise while turning. Almost sounds like a fog horn. It only happens when you release the brake and last a few seconds. Additionally, probably for the first 5 minutes of driving usually when the car has been sitting for hours or overnight when I pull out of the drive way and go to the stop sign if I push just a little harder on the pedal the rear brake will lock and I will skid a bit.

I have had two mechanics and a brake place look at it and tell me they cannot find a problem. Could it be a abs sensor or the abs electrical box in the engine where the brake line feed o or a master cylinder?

I appreciate the help this is so frustrating.

Tiny
Bababinki
Sep 19, 2010.
This is a tough one to deal with via the internet. If that brakes are good (and you have done everything) the last thing left is the wheel bearing. Is there any play in and out or up and down in the wheel itself?

I'm not a mechanic, but I do own a 2002 Ranger, and it does the same thing. I bet you either live in a humid climate or it's been raining a lot. I'm in Orlando FL, and every time it rains, and the truck has been parked for while they hum at very low speeds (more when backing up) and they grab a lot. Once they are warmed up it's fine.
Apparently it can be problematic as Ford has a service bulletin.
Ford doesn't say it's moisture, but why else would the fix be to seal up the brake drum assembly. Maybe the humidity is making the pads swell and drag more?
One other forum sugested that it might be made worse by a 'tight' adjustment of the shoes and therefore can be adjusted out. I'm going to be taking mine in next week to the shop to have them look at it.

Hope this helps.
-Oh and if you do find a solution, be sure to post it so others with the same issue can get it solved.

Tiny
Tjtsj
Sep 25, 2010.
Tjtsj, I thought I had solved the problem. I replaced the drums and adjusted the shoes. The problem went away for months, but I had a flat in January and had Sears fix it and after the put the wheel back on the problem came back. I will try sealing it up and see what happens. I live in Tampa, so maybe it is the humidity and rain. John

Tiny
Bababinki
Apr 2, 2011.
John: When you check the brakes, make sure they are not glazed. Often times the shoes and drums will glaze and cause a noise and the brakes to grab, especially when it is damp / humid / raining. To repair that type of problem, I cut the drums (the minimum amount I can) just enough to get rid of the glaze, sand the brake shoes and the problem goes away. Keep in mind, it will come back after they glaze again, but that is a cheap and easy fix. You may want to consider ceramic brakes. They are less likely to glaze or absorb moisture. THey are more expensive but will last longer.

As far as sealing the drum, it really can't be done because the drum is going to be open on the rear no matter what. It has to be.

Just some thoughts.


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