Diagnosing a warped rotor [help]

[sw0rn]

Hello, all.

I've got an 02 Ranger 3.0L, 2 wheel drive and a bit of a problem. A few weeks ago I redid my drums for the first time. Recently, I noticed that I'm getting a pretty remarkable dragging noise up front and that when I brake, I'm 1. getting a lot of travel in my brake pedal, 2. some "shuddering" or uneven brake pressure and 3. LOTS of vibration up front. When I was rotating my tires and cleaning the hubs on my wheels today, I spun the rotor by hand to see how freely they move, as I suspect a warped rotor or a seized caliper is causing all this vibration and grinding up front. When I moved the rotor, it would move easily and as it made 360degree rotation it became harder and harder to move, then freed up again. So, I suspect that this uneven movement in the rotor is the cause for all my shuddering and excitement on the highway.

Any general advice as far as diagnosing what exactly is causing this excessive brake pedal travel and how to diagnose a bad rotor/pad/etc? I've already searched through many forums, videos, and my repair manual for the general stuff; I would just like some extra input. This is my first time - be gentle.

Mods - sorry if this post is redundant, I tried finding more threads like mine.

 

[Explorin94]

Hello, all.

I've got an 02 Ranger 3.0L, 2 wheel drive and a bit of a problem. A few weeks ago I redid my drums for the first time. Recently, I noticed that I'm getting a pretty remarkable dragging noise up front and that when I brake, I'm 1. getting a lot of travel in my brake pedal, 2. some "shuddering" or uneven brake pressure and 3. LOTS of vibration up front. When I was rotating my tires and cleaning the hubs on my wheels today, I spun the rotor by hand to see how freely they move, as I suspect a warped rotor or a seized caliper is causing all this vibration and grinding up front. When I moved the rotor, it would move easily and as it made 360degree rotation it became harder and harder to move, then freed up again. So, I suspect that this uneven movement in the rotor is the cause for all my shuddering and excitement on the highway.

Any general advice as far as diagnosing what exactly is causing this excessive brake pedal travel and how to diagnose a bad rotor/pad/etc? I've already searched through many forums, videos, and my repair manual for the general stuff; I would just like some extra input. This is my first time - be gentle.

Mods - sorry if this post is redundant, I tried finding more threads like mine.

Your pedal travels farther because you need to readjust your rear drums. The rear drums are your pedal height of your brake pedal when applied. If your truck is shuddeering then you have a warped or thin rotor. The rotors need to be replaced aa well as the pads. I would evaluate the calipers also and see how easy the pistons go back into the bores with the "C" clamp. You say it doesn't stop evenly? Meaning when you brake it pulls one way or the other? If that is so it could be a bad caliper (the side it pulls to is the good rotor) or the slides of the rotor are dirty and need to be cleaned and greased. And if you decide to do rotors you will need to get wheels seals and some grease to repack your wheel bearing when your do the rotors.

 

[Sasquatch_Ryda]

You might also want to jack it back up and check to see if you have play in the front wheel bearings. Grab the top and bottom of the tire and push/pull on the tire to feel for wheel bearing play. If the grease is nice and clean, you can just readjust the bearings.

 

[sw0rn]

Thanks for the speedy replies!

Your pedal travels farther because you need to readjust your rear drums. The rear drums are your pedal height of your brake pedal when applied.

How can I readjust my rear drums to fix this excessive pedal travel?

At this point, I'm almost certain that it is the rotors that are causing me to pull to one side (only slightly, not as bad as I've had it before) and for the uneven braking (PRESSURE, less pressure, PRESSURE, ie. stop and go, stop and go).

If that is so it could be a bad caliper (the side it pulls to is the good rotor) or the slides of the rotor are dirty and need to be cleaned and greased.

What should I look for if my caliper is bad? The slides are the pins with the rubber boot, right?

And if you decide to do rotors you will need to get wheels seals and some grease to repack your wheel bearing when your do the rotors.

Are seals usually sold with new rotors? Anti-seize grease, correct?

I have a repair manual given to me by a very generous friend that details most of the process for repairing/servicing/cleaning brakes - as far as I know. Do you have any advice or tips for when I go to do this job? Something that this manual may not have included or that you think makes the job easier/more efficient?

You might also want to jack it back up and check to see if you have play in the front wheel bearings. Grab the top and bottom of the tire and push/pull on the tire to feel for wheel bearing play. If the grease is nice and clean, you can just readjust the bearings.

If they move, does this mean that there is wheel bearing play? If the grease on the bearings is clean, how do I readjust them?


Again, thank you two very much for your quick and detailed replies.

 

[Sasquatch_Ryda]

How can I readjust my rear drums to fix this excessive pedal travel?

There will be a rubber plug near the bottom of the backing plates on the rear drum brakes. Jack the rear end so the tires are off the ground with the truck in neutral (block the front tires so it can't roll) Remove the rubber plugs and use a brake spoon or a small flat head screwdriver to turn the adjuster wheel inside the drum until you can just feel it starting to cause some drag on the wheel when you spin it. Replace rubber plugs.

What should I look for if my caliper is bad? The slides are the pins with the rubber boot, right?

The piston in the caliper can seize, which will not allow the piston to retract after applying the brakes. The constant dragging will cause excessive heat which can warp the rotors. Having one caliper that is not returning and causing drag will also cause the vehicle to pull to one side or the other.

Are seals usually sold with new rotors? Anti-seize grease, correct

No, the bearing races will be in the new rotors, but you will have to purchase the grease seals separately.

If they move, does this mean that there is wheel bearing play? If the grease on the bearings is clean, how do I readjust them?

If there is play felt (and check to make sure its not bad ball joints causing the play) then yes, there is wheel bearing play. If the grease is nice and clean and the bearings are in good shape you can re adjust them. Remove the dust caps that cover the wheel bearing and lock nut. Remove and discard the cotter pin that keeps it from backing off. Snug the nut up to 35 ft lbs while spinning the rotor to seat the bearings. Back the nut off 1/4 turn and then tighten it up to around 20 INCH lbs (NOT ft lbs this time) which is basically just hand tight. Install a new cotter pin and re install the dust caps.

 

[Ranger Dave (B25)]

'Warped' rotors are not really warped at all, 99.9% of the time.

The shudder you feel is the result of hard spots in the rotor(s) caused by hard braking or panic-stops and then sitting with your foot on the brake pedal. The pads clamping against the rotors while stationary trap the heat which surface (case) hardens the cast-iron rotor faces where the pads are in contact with them. Turning the rotors and taking off about .003 -.005 per side of face material will remove the hardened spots. NOTE: before you reface the rotors, make certain that you will not go below thickness spec while doing so.

Warped (truly warped) rotors can be caused by overheating of the entire rotor/hub assembly. You will know if this happens because the rotors will take on a bluish hue and your bearing grease will likely melt and run out of the dust cap or inner seal. The smoke and smell from burning pads is a dead giveaway as well...