Rear Wheel / Brake problem

[jamie5711]

I own a 2002 V70XC AWD, 73k miles
I am having problems with the NSR wheel, I am finding that the whole wheel is getting very hot. On start off it seems ok, after I have done about 5 miles I can feel a rumble coming from the rear quarter, this rumble shakes the whole car, when I get to where I'm going I find that the wheel is excessively hot compared to the other 3. I have also found that if I carry on the rumble goes away after about 3 miles. Last night I stopped immediately after I left the motorway and found that the brake disk was glowing red hot. When I have this problem I experience a dragging effect in the car it is almost as if the brakes are being applied and released all the time this is more noticable when going at low speeds say coming to a stop at lights, it feels like the brake disk is rubbing pads I can also feel it in the brake pedal although the pads are not worn down. Does anyone have any ideas what could be causing this problem.
I have swapped out handbrake shoes (the friction surface was detached) and wheel hub/bearing (this was before I saw the glowing disk )

[kain]

Is the caliper sticking?

Coincedental that you bring this up today because I had a VW Jetta pass me today on the way into work and as it drove by I noticed that the passenger side rear disc was glowing red. Brake lights were not on so he had something going on too.

[jamie5711]

That's what I'm not sure of. I have to assume so at the moment, I can see no rough spots on the disks themselves, and it would seem that due the heat problems the pads are naff now, they seem "soft" if that makes sense, and crumbly around the edges I would think this was due to heat damage. Can you refurbish the caliper? are there any "how-to's" for this process. I have had a problem with these brakes before but it was the opposite, they didn't work I put this down to the fact I don't use the car everyday, I only do about 6k miles a year in it

[JRL]

Can you refurbish the caliper?

YES

are there any "how-to's" for this process. I have had a problem with these brakes before but it was the opposite, they didn't work I put this down to the fact I don't use the car everyday, I only do about 6k miles a year in it

CHECK THE WHEEL BEARING

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[jamie5711]

I have changed the wheel bearing/hub already

[kain]

Check the guide pins on the brake assembly too. On my old Saturn I had one of them seize up on me (grease was gone) causing the caliper to stick. Pulled it out, cleaned it off and lubed it up and it started working again.

[jamie5711]

Done that as well. I think I am looking at a piston problem but what contradicts that is the pulsing I get at low speeds and feel in the pedal. The only way I can explain it is like I'm rolling a square wheel

[06ORXC]

Pulsing is also related to disks that have hot spots and are warped giving that on/off feeling.

[jamie5711]

Agreed, but wouldn't the pulsing be there all the time? Mine starts after about 3 - 5 miles

[Astro14]

Your symptoms are from a sticking brake. Pulsing, the heat, the damage to the pads...all of it. But I wouldn't rule out the bearing until it's been checked. And "red hot" you say? This is dangerous - you can induce a bearing or brake failure with red hot brakes...

You say you've replaced the wheel bearing, so it can't be the bearing. Sometimes, new parts fail pretty quickly for some odd reason. So, eliminate that as a cause by checking it with the wheel off the ground...further, you want to ensure that it's not heat damaged now...

Then pull the rotor and make sure that the parking brake isn't sticking...

Once those are checked/eliminated, you need to determine the cause of the sticking brake. Most likely it's a caliper problem, as previous posters have replied. You need to troubleshoot this too, by (safely, please!) checking the action of the brakes. Get a helper to step on the brake pedal with the car up and the wheel off. The pads should retract just a hair when the pedal is released...just enough to clear the rotor.

If they don't, then it's sticking. If the pads are really unevenly worn (one is more thin than other) I would suspect the pins are binding. If they just plain don't retract, then it's the caliper.

Once in a great while, a brake line will fail internally, causing it to act like a one way valve. So, if you end up replacing the caliper, check the action of the new one to ensure it all works correctly.

Regardless of cause - I would replace both rear rotors and sets of pads once you've found and repaired the cause. One side is toast already, and you want to replace in pairs.

Good luck.