Brake Caliper Problem Solved (Post #282) 1/16/2012

We had an uncharacteristically warm Saturday just in time for me to sort out the problem with the brake caliper on the Range Rover. As you may remember I came home to find this in my driveway.

As you can imagine it was very disappointing. I knew it was behaving like a warped rotor. As I mentioned in my previous post those rotors were brand new. I got the parts in and found brake fluid at a store I normally don’t shop in, Pep Boys. Its good to know someone around here stocks Castrol LMA Dot 4 brake fluid.

As I mentioned Saturday morning came around and I pulled the Range Rover into the garage with only the hand brake to slow me down. I ordered brake calipers for the entire rear axle. I figured if one had failed the other would be near enough to fail as well. My son’s friend “Scuba” wanted to learn about brakes so I told him to come over when he was ready. I started and not long after he wandered in. He is studying mechanical engineering and would like to be a automotive designer/engineer for BMW after he graduates.

So back to the caliper. I got her jacked up and got the tire off and started looking at what might have happened. What I found was very, very disappointing.

I noticed a wear mark on the rotor.

The wear marks are only on part of the rotor. This would account for the whomp, whomp sound. So I looked at the brake caliper. The brake pad was dragging on the rotor. This is not designed to happen. So I looked at the caliper for an explanation.

The brake caliper had two distinct wear marks. With the caliper in place the brake pads were definitely rubbing on the rotor. I showed Scuba how the caliper works and we thought about the design and what might have failed. I decided to fit the new caliper and see if we had the same conditions.

With the new caliper in place we didn’t see any contact between the rotor and the pad. as I was looking at the setup I noticed something not quite right.

There was a gap between the rotor and the hub. There should not be a gap there. I examined it even more closely and noticed the hub and rotor were touching on the opposite side. But on this side they were separated.

This causes rotor to wobble and as it was rotating it was causing vibration and parts that have very tight clearances were now rubbing on each other. This caused a couple of bolts to be shaved off a bit.

I removed the hub and rotor and found even more damage. The ABS ring was also not properly attached to the rotor. That was apparent from the nyloc nuts that were not properly tightened down.

You can see everything the the following picture. How it stayed together I will never know.

It goes without saying, but I’ll say it anyway. The brake rotor was scorched and had to be replaced. The brake pads were ruined from heat. The brake caliper seal had failed and need to be replaced or refurbished. I had sourced that part but the pads and the rotor were another thing.

I went to O’Reilly’s Auto and they told me they didn’t have one in any store or in the warehouse. I went out to the parking lot and called NAPA Auto. The kid there told me they had pads and rotors in the warehouse and could have them brought to the store in Norman by Monday. The good news in this is the warehouse is in Edmond. So I called the kid back and told him I’d just drive up there (35 minutes) and pick them up myself. So I did. Ricky was fun to chat with as they pulled my parts.

I headed home and found myself on the road where my family is buried. I stopped to see the burial plot. I didn’t stay long.

I got back to the garage and started disassembling and reassembling the parts. In the reassembly I used red thread locker on the bolts that go in to the ABS ring. I used blue thread locker on EVERYTHING ELSE.

I had lost an entire quart of brake fluid. I emptied the full contents of the bottle into the reservoir. Scuba pumped the brake peddle as I bled the air out of the line and caliper. We hopped in and took her for a ride around the block. All was well.

Conclusion.
How on earth did those bolts come out? I know for sure that I tightened the bolts. I remember how I rigged up the breaker bar. I remember the reassembly. There was no thread locker on the bolts when I disassembled it. This was the main reason for not putting any on when I initially did the brake rotors.

I will definitely have the driver’s side rear off to check for assembly. If this could occur on the passenger side it could occur on the driver’s side.  Better to find the problem before it destroys that side.

I have had nothing but trouble with that corner (passenger side) of the Range Rover since I did the last restoration. Was I exceptionally tired that day? Was I loco de color that day? It was exceptionally hot that summer.

Well that is all. I have a few other projects that demand attention. First and foremost is the driver’s side door handle. My son Diet Mtn Drew managed to nearly rip it off when he borrowed the the Range Rover while his Scion was in the shop. The main problem is the latch needs adjustment. I will look at that when I pull the door card and sort out the bad handle. I also have to fixed the faulty brake peddle switch.

School starts back on Tuesday. My next free time will be during Spring Break. Let’s hope nothing breaks before then.

Thanks for reading and Happy Rovering.