Rear brake discs and wheel bearings (from old site)

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contributed by Rich Russell
Changing the rear brake discs and wheel bearings sounds scary, but in practice takes only about an hour on a GT Turbo.


The rear wheel bearings are pressed into the rear brake discs, rather than a hub as such. So it makes sense to replace discs and bearings at the same time. If you get your bearings and discs from the same place, they might press them in for you. Otherwise you will need to use a vice or press and some metal tubing to put them in. Make sure you fit the circlip to hold the bearing in place.

First chock the front wheels of the car, jack up one of the rear corners and remove the wheel. Put an axle stand under the suspension arm.

Remove the metal cap from the centre of the brake disc. Loosen the hub nut found behind the cap - you'll need a 30mm socket. This will be tight, so you may struggle to get it to move. Having the handbrake on helps hold the hub still.

A useful tip is to remove the axle stand, refit the wheel, lower the car to the ground, then use an extension through the centre of your wheel to get to the nut (depending on wheel design). The weight of the car helps a lot. Then jack the car back up, and put the axle stand back under.

Once the nut is loosened (don't undo it yet), take the handbrake off (you'll be removing the brake pads, which you can't do if the brakes are on!). Now remove the small metal clip at the back of the sliding bar that secures the brake pads. Tap the sliding bar out - you may need a hammer and a metal bar (big screwdriver) to help it move. If it's rusted in, a bit of PlusGas or WD40 should help.

Remove the pads, and put the anti-rattle springs in a safe place (note how they were fitted before removing). Remove the two 17mm bolts holding the caliper frame to the caliper.

Now remove the hub nut, and the thick washer behind it. Remove the disc/bearing - it should just slide off, but if yours is stuck, a rubber mallet should help free it. Remove the collar from the stub axle too.

Using a screwdriver, wind the piston into the caliper by turning it clockwise. Note that there are four gaps in a ring on the piston to help do this. On the inside pad is a lug that slides into a gap - so make sure you leave the piston with a gap pointing at 90 degrees to the frame, so this will line up (you can always move it a little when you come to fit the pad if you don't get it quite right).

Clean up the washer and collar, and the axle. Apply a little grease to the axle.

Your new discs will probably have a coating of grease to prevent them corroding. Use brake cleaner and a clean cloth to remove this. It's worth giving your new pads a wipe with brake cleaner too, in case they have a coating.

Slide the collar back onto the axle, then the new disc/bearing, then refit the washer and a new hub nut (should have come with your bearings). Tighten the hub nut enough to hold the disc still, but don't try to do it up fully yet.

Refit the caliper frame, and tighten the bolts up to 60Nm with a torque wrench. Insert the new piston-side brake pad. You might need to turn the piston slightly to get the lug to line up with a gap. Refit the other pad, then tap in the slide bar. You'll have to hold the pads in a certain position to leave the correct gap for the bar, but it should slide back in (maybe with a bit of light tapping with a hammer). If it's very rusty, you might have to clean up the bar with a file and glasspaper. Don't forget the little metal clip in the bar. Then refit the anti-rattle springs.

With a torque wrench, tighten the hub nut up to 160Nm. Refit the cap over the nut.

Remove the axle stand, refit the wheel, and lower the car to the ground.

Inside the car, press the brake pedal a few times to re-engage the pads with the disc. Then apply the handbrake.

Repeat for the other side.

Be aware that the new discs and pads will have very little braking effect initially (because they're smooth and shiny). So your handbrake will be virtually useless. Go for a gentle drive, applying the brakes very gently to scrub the discs in. You will need to brake gently for a few days until they bed in properly. So be careful and slow down well in advance of junctions. Also be aware that the handbrake won't be very good until they're bedded in, so avoid parking on hills (without leaving it in gear at least). Once the pads and discs are bedded in properly - on average about 100 miles of normal driving - braking performance should be good.

Make sure you brake gently for a week or so after doing this to bed the brake pads and discs in. </TD><!-- Spacer --><TD width=15> </TD><!-- Images --><TD width=200>https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Remove the wheel.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Undo the hub nut

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

If tight, refit wheel and try again.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Slide out the pad locking bar.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Remove the caliper frame.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Remove the disc.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Wind in the piston.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Fit the new disc.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Refit the frame and new pads.

https://www.rtoc.org/articles/i/autof...14_150x112.jpg

Tighten hub nut to correct torque.
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