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Replacing my first set of brake pads
beagley - 9/7/09 at 02:18 PM

My boss has asked me to help him replace the pads on his Mini Cooper. I've seen it done a few times and doesn't look too complicated, but that's what I thought about repairing drywall.

Is there anything in particular that is a surprise with the Cooper's brake system that I should keep aware of?

Also...... any tips?


Mr Whippy - 9/7/09 at 02:24 PM

is this a new one or the orginal mini?



[Edited on 9/7/09 by Mr Whippy]


beagley - 9/7/09 at 02:26 PM

This is a new school mini. I think its an '06


Mr Whippy - 9/7/09 at 02:31 PM

Totally standard brake caliper on the new ones. Here's a quick link to a web how to -

linky

take off the reservoir cap and keep an eye on the level as it will rise as you push the piston back, brake fluid removes paintwork. A small smear of copper grease on the back of the pad helps stop brake squeal. Don't use any other type of grease due to the heat.

[Edited on 9/7/09 by Mr Whippy]


beagley - 9/7/09 at 02:41 PM

Thanks for the link. I had found another like it, but it's nice to see one specific to a mini. I'm looking forward to getting into it. I'll try to take some pictures for proof!


DaveFJ - 9/7/09 at 02:45 PM

just dont do what a friend of mine did!
forgot to pump the brakes again after changing the pads.. just drove off and couldnt stop - straight into a lamp post!

naturally we were overflowing with sympathy and didnt criticise his knowledge (he is an engineer) or driving ability

[Edited on 9-7-09 by DaveFJ]


pewe - 9/7/09 at 04:23 PM

IIRC if it's fitted with ABS the general recommendation is to clamp the brake line with a proper clamp (not Molegrips!) and release the bleed nipple (with suitable drain tube attached) so the pistons to be pushed back to allow the new, thicker pads to be inserted into the caliper.
Failing to do this can evidently upset the electronics associated with the ABS.
HTH. Cheers, Pewe


britishtrident - 9/7/09 at 05:08 PM

As above with ABS pushing the fluid back is not a good idea also --- The BMW Mini thing is not DIY friendly.

The first hurdle is you will have to check if you can get the wheels off ---- I jest not.

On some of these cars BMW did not provide a key to remove the locking wheel centre covers it was a dealer special tool.

If the car either has a key provided or hasn't got locking wheel covers you may then find the wheels are corroded on.
Way round this is refit the wheel nuts but leave them slack by a turn or two, then drive the car forward and backwards for a meter or so each way applying the brakes sharply.

[Edited on 9/7/09 by britishtrident]


DorsetStrider - 9/7/09 at 05:12 PM

quote:
Originally posted by pewe
IIRC if it's fitted with ABS the general recommendation is to clamp the brake line with a proper clamp (not Molegrips!) and release the bleed nipple (with suitable drain tube attached) so the pistons to be pushed back to allow the new, thicker pads to be inserted into the caliper.
Failing to do this can evidently upset the electronics associated with the ABS.
HTH. Cheers, Pewe



Spot on.

If you push the fluid back to the resevoir on an ABS equiped car there's a better than 50/50 chance you'll wreck the modulator in the ABS pump so no more abs.

Also don't forget to pump the pedal before driving off.


Gazeddy - 9/7/09 at 05:45 PM

where are you guys getting this info about abs and pushing the piston back. i work at a main stealer in the workshop and we ALWAYS push the psiton back and in the last two-three years we've never had one comeback with abs failure. but the bmw mini is horrible to work on


DorsetStrider - 9/7/09 at 06:29 PM

3 years motor mechanics collge,
2 years working in the industry,
Member of the IMI.

Current teaching is that on ABS equiped vechicles you must prevent brake fluid going the wrong way back up the system.


Gazeddy - 9/7/09 at 06:33 PM

Our service literature says push piston back I'm sure it does


DorsetStrider - 9/7/09 at 06:43 PM

Maybe your vehicles use an unusual abs system where it's not nessicary?

Either way it's still best practise to clamp the line and open the nipple (oh er MRS!).


britishtrident - 10/7/09 at 06:51 AM

The problem with pushing the pistons back is two fold.

(1) On older higher mileage cars a lot of wear debris accumulates in the brake system, pushing back the fluid tends to push it into the ABS assembly where it can damage the valve seats.

(2) One particular manufacturers models it is not unknown to master cylinder failure if the fluid is forced back.


Ninehigh - 10/7/09 at 10:55 PM

quote:
Originally posted by pewe
IIRC if it's fitted with ABS the general recommendation is to clamp the brake line with a proper clamp (not Molegrips!) and release the bleed nipple (with suitable drain tube attached) so the pistons to be pushed back to allow the new, thicker pads to be inserted into the caliper.
Failing to do this can evidently upset the electronics associated with the ABS.
HTH. Cheers, Pewe


I've recently had a go at doing the rear ones on me mondeo, Haynes manual said to do the same thing about clamping because the backward flow of brake fluid can cause some rubber seal or valve to pop inside out/backwards and the whole braking system fails.

Paid £30 for a mechanic to do it in the end, cos it was going to be a pita with the handbrake attatched to it


prawnabie - 10/7/09 at 11:08 PM

Judging by the fact its your first set, would it not be better do them under the eye of a competent mechanic?

Not having a go or anything, but brakes, especially someone else brakes, need to be spot on.


pewe - 13/7/09 at 12:48 PM

Regardless of the ABS issue I always feel that bleeding the caliper reduces the chance of brake fade because you are replacing the older, cooked fluid from the caliper and replacing it with "fresher" fluid from further up the line.
As we all know (don't we?) fluid should be replaced every couple of years.
Cheers, Pewe


Ninehigh - 13/7/09 at 08:02 PM

quote:
Originally posted by pewe
As we all know (don't we?) fluid should be replaced every couple of years.
Cheers, Pewe


I didn't actually, there's another job to add to the list!