Question on changing discs and pads please

[Pondrew]

Sorry, me again.

I think I am going to change the discs and pads all round on my e89 myself. I have had a look at how to do it, looks pretty straightforward as long as the caliper bolts come off fairly easily and I can compress the pistons when putting calipers back!

I have decided on TRW discs and pads (as they are an OEM supplier, are mid-range pricing and do some nice black painted ones).
I can get the parts for 1/2 the quote from my local "specialist" and they will supply inferior parts.

I have three questions:
Do I need to replace the wear sensors, or can the existing ones be re-used? Am I right in thinking only one side per axle has them? They are not anywhere near down to the sensors on any wheel.

If I do replace, will they need to be "addressed" to the car? As I obviously can't do this.

Any advice appreciated

 

[mr.tourette]

You can reuse them if you can remove them without any damage to them. Yes only one per side. Don't think you need to register new ones but not 100% on that

 

[Bombardino]

On the grand scale of things it’s worth replacing them as they don’t exactly cost the kings ransom.
One per axle.

 

[Smartbear]

You can use the sensors again as long as they haven’t triggered a red wear warning, you need new ones when that happens
Rob

 

[Pondrew]

Thanks guys (as usual).

So we don't think they have to be addressed if changed?

 

[Pondrew]

On the grand scale of things it’s worth replacing them as they don’t exactly cost the kings ransom.
One per axle.

It's an extra £23.86 for the two. I'm not made of money!

 

[Smartbear]

Thanks guys (as usual).

So we don't think they have to be addressed if changed?

If replacing pads it’s possible to reset the wear sensors (a maximum of two times i think)
Rob

 

[flybobbie]

My experience they generally break when you take them off. I would buy new ones and fit and save a lot of aggro and delay finishing the job.

 

[Pondrew]

My experience they generally break when you take them off. I would buy new ones and fit and save a lot of aggro and delay finishing the job

OK I will order them with the big round lumps of steel. If I can manage to save the old ones, I will have a spare new set, so win, win I suppose.

 

[Pondrew]

Just had a thought.

I presume the electric handbrake uses the rear discs? If so I will have to release this to do the rears; does it automatically reset itself after a period of time and will I have to disconnect the battery? My other cars put the handbrake on if I forget.

Ta

 

[Smartbear]

Just had a thought.

I presume the electric handbrake uses the rear discs? If so I will have to release this to do the rears; does it automatically reset itself after a period of time and will I have to disconnect the battery? My other cars put the handbrake on if I forget.

Ta

The best way is to unbolt the motor from the caliper
Rob

 

[Pondrew]

I just watched a you tube video regards re-setting the handbrake; it looked bl00dy complicated. I will have a look, as I've ordered all the parts now. If the worst comes to the worst, I'll take it (carefully) to my local bloke. Luckily he's only a mile up the road!

 

[Pondrew]

I should take note of my own signature

 

[Chris_D]

It's worth getting clued up and having a crack at it yourself as once dis-assembled you can spend time cleaning everything up and painting the calipers if required. Your local indy won't even think about doing this and if you asked him he'd only probably get poundsigns ringing in his eyeballs! :lol:

Make sure you use plenty of copper grease on applicable surfaces to prevent bonding in the future.

 

[ajguk]

I haven't done the rears on mine yet, but I did do the front discs and pads (and sensor). One thing to watch out for is the guide bolt on the disc, mine was completely seized and I rounded the allen bit off which caused a few nervous minutes, had to drive (other car) to the local indy and buy some bolt extractors, basically a chisel you hammer in, then it came straight off. From memory I put the new bolts in using some copper grease on the bolts in case I ever have to do them again.

Just worth being prepared and careful with those bolts, they seemed quite soft on mine hence the easy rounding. Good luck, hope the electric handbrake is easy as I might want to do mine this year.

 

[kinger]

Only one sensor per axle, on the drivers side rear and passenger side front,
The rears are pretty easy, just split the motor from the caliper and wind it back with a T sockect
No need to register them, i used the old one but was unable to reset the brake service indicator, as soon as i fitted a new sensor everything was fine.
Touch of copper slip on the threads and on the face of the hub that the wheel touches helps the next time you want to take a wheel off.
Mike

 

[clarker63]

I just watched a you tube video regards re-setting the handbrake; it looked bl00dy complicated. I will have a look, as I've ordered all the parts now. If the worst comes to the worst, I'll take it (carefully) to my local bloke. Luckily he's only a mile up the road!

I did my rear pads/new sensor recently. isn't that hard to wind the handbrake back. You may have to reset the warning light (mine came on because of time, not because of wear). there are guides online on how to do it. I just didn't realise you have to have the handbrake off when resetting it. otherwise it remains (stubbornly) on, despite all the work you've done

 

[Nictrix]

On refitting the rear calipers do not use the ebrake until after you have pumped the pedal to close up the gap between the pads and the disc

 

[Pondrew]

Thanks for all the useful advice as always!

I left the car with the handbrake off overnight and GOOD NEWS; it doesn't re-apply itself after a period of time which should make the rears that much easier. Just need to remember to chock the other wheels when I lift it.
I will squirt plenty of WD40 into the disc allen bolts and leave that to soak for a while, hopefully should help with removal.

I have ordered 4 No. TRW discs (black painted hubs/spacers), TRW pads all round (red DTEC low dust for the front), two TRW wear sensors and a Blue Print disposable air filter. They came to £288.62 all in delivered.

 

[maxman]

I would buy new wear sensors,mine fell apart when I tried to take them out.The bolts that hold the motor on the rear calliper are not very strong .Make sure you clean before you insert the torx bit.Thats the only awkward bit.There are YouTube vids showing how to screw the motor back.