X5 – Rear Brakes Overhaul

The X5 had three advisories on its recent MOT. One was a worn rear tyre, and those have already been replaced. The others were:

  • The Park Brake has just met the required efficiency it appears the Brakes require service or adjustment
  • Rear Brake disc worn, pitted or scored, but not seriously weakened (1.1.14 (a) (ii))

The parking brake was adjusted by the trader, but I don’t care much about handbrakes on automatics, so I wasn’t too worried about it. The rear brakes were functional, but the corrosion on the disks, hub and caliper really let the vehicle’s appearance down – as noted when fitting spacers.

Crusty rear disk and hub

It was this more than anything else that led me to check the cost of replacement parts, and at £145.93 from ECP for rear disks, pads, sensor and handbrake shoes, I decided to crack on. A key incentive was to take the time to clean everything up – that’s always the benefit of doing these kind of things myself. So a quick spoiler – the above now looks like this:

Getting there however wasn’t easy at all – the job took me a day and a half. Why? Four reasons:

  1. Access to the lower caliper slider bolt is inhibited by the rear shock.
  2. The disks were rusted onto the hubs.
  3. I’d not replaced the handbrake shoes before, and I found that part tricky.
  4. Adjusting the handbrake is a bit fiddly.

So I started the job at the rear left. Getting the X5 into the garage and up in the air is a bit time consuming in itself.

I didn’t photograph the rear shock obstruction. The issue was that my 7mm on a 3/8″ drive would fit onto both lugs, but I couldn’t get the 3/8″ drive onto the back of it in the lower hole due to the shock being in the way. I tried to remove the shock. While I could remove its bolt, I couldn’t separate it from the hub, and I didn’t want to force the issue in case I couldn’t get it back on again.

I tried turning a 7mm allen key with a 7mm spanner, but that snapped my spanner. So I went in search of a better tool. Halfords sold me a Laser Brake Caliper Key for a few quid.

Laser Brake Caliper Key 7mm

That also turned out to be useless because the shock was also in the way. So I chopped it up with my angle grinder.

The resulting tool was perfect! That investigation and experimentation took about an hour and a half which was really dull. Seconds later the caliper and carrier were off, and then I ran straight into the next problem: the disk was at one with the hub and wouldn’t be separated.

I tried all the usual with a hammer, from tapping to full on wallops. Naturally I feared for the wheel bearing so didn’t get too carried away, so I was stuck unable to remove the disk.

I found a great video by Ben Eytalis which inspired me to push the disk out with a couple of bolts in the carrier bolt holes.

That got things going again, but had absorbed nearly another hour. Then I could inspect the handbrake arrangement.

The dog came to help.

The outgoing handbrake shoes weren’t worn as such, just old. As I’ve said, I don’t think handbrakes are used much at all on automatic cars.

Hub with parking brake removed:

Cleaned up with new shoes all fitted.

Reassembling that was a proper twat. Various YouTube videos suggested it could be reassembled without the springs fitted (easy), and then the springs could be popped into place with encouragement from pliers or a screwdriver (not feasible IMO). I managed it by assembling with the springs first, then using the jack and an extension bar to prise the assembly open around the metal bits. Of course, that took me a while to figure out.

Then came all the rewarding stuff. New disks – took years off the car.

The carriers and calipers were brushed off, rubbed down and painted.

Slider pins were cleaned up and re-greased. New pads went on.

Then with lessons learned, the other side of the car took far less time.

Not forgetting the pad wear sensor on this side.

At that point I popped the wheels on and adventured outside for the massive joy that is handbrake adjustment. With that done, I popped the spacers and wheels back on.

I’m really pleased to know that all aspects of rear braking have been cleaned up and refreshed. Trouble is, now the front hubs, disks and calipers let the side down. ECP have a post-Christmas sale on at the moment – front disks, pads and sensor come in at £178. Hmm!