replacing rear pads/discs, any special tools needed?

[taffy bhoy]

2005 2.5 z4. we are looking to replace the rear discs and pads shortly, do the pistons just push in on these or do they need winding in?

 

[Stevepj]

The pistons should push back in, the tricky part is slackening off and adjusting the hand brake as you have to fish through one of the wheel bolt holes to move the adjuster mechanism with a screwdriver or similar.
Watch a few videos on youtube to see how it's done.

 

[Z4 Gaz]

Push in, no special tools required.
Apart from maybe a large hammer to free the old discs.

 

[taffy bhoy]

brilliant, cheers both, and yes handbrake is being done too. seen a few vids on that. havent found one specific to the z4 yet, but from what i have seen, you have the adjuster cogs through a bolt hole, and the nuts under handbrake? same system on the z4?

 

[Lance]

Mines a 2.5 and I changed my rear discs myself (after 50k miles) discs came off over the handbrake shoes, caused no issue whatsoever, can't see why you would need to slacken off the handbrake via the adjusters. Just make sure the handbrake is off when removing the discs. Pistons definitely just push in.

Tip, have a good fitting 16mm spanner/socket for removing the caliper carrier, preferably with added leverage, it's very tight!!
Tip 2 - The grub allen bolt holding the disc in place, use a good quality tool for removal. Chew the head on this and the straight forward job becomes a real PITA.

Good Luck

 

[MJJamieson]

You need to put the auto adjuster on the hand brake mechanism in a service position, can be a pita.

 

[MrPT]

Tip 2 - The grub allen bolt holding the disc in place, use a good quality tool for removal. Chew the head on this and the straight forward job becomes a real PITA.

This!

Stop the moment you feel like you might be starting to ruin the head of the bolt. They should only be finger tight but it's not uncommon to need heat/wrench/penetrating fluid/dremel to remove them.

Also make sure the pistons are clean and true when you push them back (e.g. push against the old pad or a plate). That will minimise the chances of them seizing. Rears rarely do this though.

I'd also recommend spraying the disc vents and hub with silver heatproof paint before you put them on (unless they are already coated).

 

[taffy bhoy]

ahh right, handbrake is different to the guides i have watched, they had 2 nuts to tighten under the handbrake, will have to see whats involved with that spring

 

[Z4 Gaz]

Mine came off last weekend without having to adjust the handbrake in any way. One needed a bit more persuasion than the other, hence my hammer comment :lol:

Once you are done you will probably find the hand brake is useless. Drive along and pull it on a few times to bed in the handbrake surface area on the new discs. Should work fine afterwards, mine does.

 

[Lance]

Taffy, have a think about the handbrake, the shoes shouldn't wear as they only contact the disc hub when applied, there should be no lip on the disc hub as I'm guessing you're not driving with the handbrake on? Any slack is due to cable stretch and shouldn't interfere with the disc change.

 

[Newbers]

IMG_0513.JPGYou need to put the auto adjuster on the hand brake mechanism in a service position, can be a pita.

Can anyone help - If I compress the spring and slide over to service position, how do I late get it back to normal working position?

 

[Steve84N]

Put the handbrake on.

 

[Newbers]

So is this already in the service position? (It's how I found it....)

 

[Newbers]

Got it. What a palaver.....
I think BMW adjusted my hand brake on a service at about 50k miles. I think they must have done it wrong
Anyway quite a lip on the inside of the drums.