Dreading first Brake Job...

[e34.535i.sport]

Hi there. I'm about to attempt to change the rear pads and discs on my '90 535i sport, with standard dealer parts.

I'm not looking forward to the job (have to do it MOT is coming up!) as i've read the haynes manual so many times and searched this forum for so long, and i still don't feel confident in knowing entirely what to do. I also read Bruno's piece which helped a little, but i'm worried about the brake fluid. Is it best just to remove some from the resevoir and re-fill it afterwards? If so how much?

I know its a big ask but if anyone could outline the procedure for me from their experience i would be MOST grateful. I've done a lot of other repairs on the car and maintenance work and my confidence is definitely growing, but the brakes are a big thing for me - if i do it wrong someone could get hurt (not just my wallet!).

I appreciate all advice, thanks, John.

[Ferret]

Hi there. I'm about to attempt to change the rear pads and discs on my '90 535i sport, with standard dealer parts.

I'm not looking forward to the job (have to do it MOT is coming up!) as i've read the haynes manual so many times and searched this forum for so long, and i still don't feel confident in knowing entirely what to do.

Dont worry about the job, it's literally a case of 5 bolts a wheel :)

You'll need a breaker bar, you wont be able to do this job without it.

Some thoughts:
There's two difficult spots to this - firstly getting the caliper carrier bolts out and then getting the locking/retention pin out of the rotor/disk. If your car is on its original rotors, you're probably looking at a set of seized locking pins - you're going to need to drill them out.

Which means you end up with a hub with half a locking pin in:
http://i11.photobucket.com/albums/a190/Ferret101/IMG_9359.jpg

You can either drill this and pull the stud out, or if you're lazy like me you'll have only drilled the eact amount necessary to get the rotor loose - and not bother removing the rest of it, using the calipers to hold the new discs in place rather than the locking bolt.

I did get pissed off with one side as my drill was getting flat batteries- and took a lump hammer to the rotor on the opposite side to the locking bolt. The whole rotor just jumped off the hub with about three hefty blows. I wouldnt recommend this though as you then have to somehow extract the bolt from the hub with some sheared metal around it. Chisel and file needed.

Getting the carrier bolts out requires a fair bit of force, but so long as you've got a long breaker bar, they /will/ come out. Having said that - my flat mate who's not particularly a big guy couldnt get them to come out - whereas I could put a bit of weight behind the bar and cause the bolts to pop free. These are easy to do on the front wheels, but you might have to get physical to access the rear ones. For this task you need a high quality socket because of the huge amount of force you need to transmit.

Other things you'll need: Copper grease - if you dont grease up the back of the pads they'll make a horrific noise every time you touch the brake pedal - hugely embarassing.

A good quality Hex drive - avoid the halfords hex drive 7mm tool - mine kept exploding and nearly took my eye out once - they just cant cope with the torque required to get the caliper guide pins out...

I'd recommend a good pair of axel stands for this one due to the force required - although I was crazy and did it on the widowmaker jack that comes with the car.

[Ferret]

I've just remembered that there's the spring on the front of the caliper...

There's a knack to removing this spring - you need two large screwdrivers. You have to lever the spring outwards from the centre back towards the caliper body, then use the second screwdriver to get under the clip points and lever it outwards.

This is quite hard to explain - I might have to draw a diagram but you'll be able to work it out.

[e34.535i.sport]

I'm hoping this isn't the case for me - but pretty much all the jobs i've encountered so far have involved troublesome hardware. My friend bought a HUGE breaker bar last week to get the bolt out of the engine that holds the idler wheel on so at least i can use that...

Unfortunately though I only have hand tools and ironically i went to hafords today and bought a 7mm allen key with a grip on it. :D I have a little trick up my sleeve for the bolts though as my wheel nut wrench has a hollow inner and works well for extra leverage. To be honest i don't even have a drill - and if i did i wouldn't know how to drill a bolt out!

My car has 150k miles on the clock, so i'm presuming the discs've been changed... however the fuel filter hadn't been changed since 1993 (14yrs) when i done it a week or so back - which is pitiful of the PO.

I do a lot of work on the jack - normally put an axle stand under just incase but i am amazed at how well it works! My friend just purchased a '92 e36 320i, now the jack that comes with that is SCARY! Recently i changed the sway-bar links by hand without a problem on the jack, took some force but no hernias etc.

Did you siphon out any brake fluid when doing your pads/discs? A big syringe would be very handy...

I just need some good luck with these bolts first of all...

Thanks a lot for the swift input.

[leicesterboy15]

I have these fun and games lined up soon, good luck and let us know how you get on! Have you priced up standard dealer parts with upgraded aftermarket ones? I wouldn't be surprised if they were about the same price. On my 535 a set of adjustable shocks (Spax i believe) were half the price of the replacement mtech ones from BMW and I had it on good advice that they were as good if not better and I got a good stainless Exhaust much cheaper than the BMW supplied one which would eventually need replacing anyway. Just a thought..

[e34.535i.sport]

Hey there yeah i done just that today; went to research some non standard performance parts (pads and discs) in a BM place nearby and he quoted £100 inc VAT. I ended up getting stock parts for £107.98 which i would always prefer to use (i don't know why!).

I hear you on the exhaust though, definitely the way to go. Luckily the Po had the exhaust done not long before i bought the car - all looks amazing underneath.

The M-tech shocks are £500 each from the dealer! I was literally scared when I asked, but the parts guys in the local dealer are very down to earth so we had a bit of a laugh over it. I will definitley be going with aftermarket versions when they need doing, which i'm hoping isn't soon.

I'll let you know how i got on with the brakes though, and i'll get a write up done to help any other rookies like my fine self!

[Zeuk in Oz]

Just start and see how you go. You have nothing to fear but fear itself. If you run into a snag, just post a question. As for doing it properly, have no fear - it is mechanics by numbers - you can't do it other than the right way.

I have just replaced rotors, pads and sensors on both of my E34 vehicles without any significant dramas at all - didn't need to drill anything out - just needed a little leverage ! :D I have now just started on my E39.

I just have a mottley collection of tools that seem to do the job.

Trust me, if I can do this, anyone can.

[Ross]

It's peanuts.
Read the Bentley, clean the crap out of the disc retaining bolt and give the proper size hex socket(6mm?) a good whack into it before attempting to unscrew it.

[Jeff N.]

Are you replacing your fluid or just concerned about overflowing the reservoir with new pads?

If replacing the fluid - yes, it helps if you can suck out the old fluid from the reservoir first. Not required but maked the job a lot faster.

If just concerned about overflow due to the new pads, it really depends how close the fluid is now to the top of the reservoir. If you have about a 1/2 inch of space or more, you should be OK. Do the first brake and then see how much it moves up.

You can replace the pads and rotors without cracking the caliper lines. If you crack open the caliper lines, you'll need to bleed the brakes. Avoid cracking them if you can.

Oh yes - latex work gloves or similar are a godsend when doing this job. Brake dust and brake fluid co-mingled are amongst the worst and grimiest things ever.

[Bin_jammin]

Widowmaker jack? My buddy emailed this to me months ago, I couldn't breath I was laughing so hard :D

[Shankster]

I'm in the middle of the rear brakes. Done one side (right). Have the left disassembled but its too dark to continue working.

Tools Needed:

7 MM Allen Socket (guide bolts)
5 MM Allen Socket (rotor set screw)
15 MM Impact socket or good quality regular socket. 1/2" drive.
Ratchets
Breaker bar
Torque wrench
Electric drill.
Files (optional).
Some kinda flat piece of metal or wood for pressing the piston back
7MM wrench or socket for bleed valve.
C Clamp.

Other supplies:
Choice of abrasives (wire wheels, sanding discs etc).
PB Blaster or equivalent
Loads of brake cleaner
Anti sieze paste.
Gloves (this is a messy fing job)
Safety glasses.

Bentley has a very good procedure for doing this.

Jack up car and support on stands. Make sure parking brake is off. Leave car in gear.

Remove the wheels.

Liberally spray the carrier bolts and rotor retaining screw with the penetrating oil. Do the bleeder screw also. I skipped this one and stripped the bleed screw on passenger side. Whoops.

Use screwdriver and pry the anti rattle clip out. When you're looking at it head on, stick the screwdriver in the back of one of the center holes and lever out towards the front of the car. Remove the clip.

On the back of the caliper are two little rubber caps. Remove these.

Guide bolts can now be removed with the 7MM allen socket.

Using a flat screwdriver, push the pads away from the rotor, from the back of the caliper.

Caliper can now be removed. Dont let it hang by the hose. Set it on top of an upside down bucket or on top of the trailing arm or hang it from the coil spring. Trailing arm or bucket works best so you have room to whale away at the carrier bolts.

Whale away at the carrier bolts. Remove carrier. Breaking a 3/8 drive socket and adapters is optional extra.

Remove rotor retaining screw.

Remove rotor.

Get your drill and abrasive stuff. Clean the hub till its nice and shiny.

Bolt carrier back in place till its finger tight.

Use the drill to clean the pad contact points till they are nice and shiny too.

Do the same for the caliper pad contact points.

Remove carrier and clean the bolt holes and mating surfaces with the drill.

Clean caliper and carrier with the brake cleaner.

Coat hub with anti seize paste.

Clean rotor with brake cleaner. Then with warm water and soap. Dry it and one more pass with the brake cleaner.

Install rotor to hub and reinstall set screw. Use a little anti seize on the set screw threads before installing. You can finger tighten some of the lug bolts to help line things up and keep them in place.

Place a shop towel or something over the rotor where the carrier and caliper go. Make sure to cover both sides.

Grease the carrier pad contact points and install carrier. Torque carrier mount bolts.

Apply the anti squeal paste or something to the backs of the new pads.

Clean guide bolts. Grease or no grease, theres another thread with a discussion on this topic. I greased them up. Bentley says not to.

Remove the paper towel from the rotor.

Place outboard pad on the carrier.

Press caliper piston back and install inboard pad in caliper. Dont forget the wear sensor.

Replace caliper.

Install guide bolts. Tighten.

Reinstall the covers.

Connect wear sensor.

Repeat for other side.

Apparently you will have to readjust parking brake when all done. But i havent got to that point yet.

I'll try and take some pictures but Bentley is actually pretty good for this one.

[e34.535i.sport]

Zeuk - thanks for the support, i'm hoping my tools are of a good enough quality toget these bolts out though! I don't have a torque wrench either so it'll have to be done F-T!

Ross - I'm using a haynes manual at the moment until i can me a Bentley, from this board i gather they're a LOT more useful?!!!!

Jeff N - I'm just wanting to do the pads, i'll leave the fluid for now... hopefully!!!! Thanks for the advice, i'll probably remove enough to leave a good inch at the top, do you think that'll be ok? On bruno's site it says watch that it doesn't go too low??

Shankster - Muchas gracias! I really appreciate your efforts there - I took a lot from it. I'm hoping to have a good look at it all tonight, and do them saturday morning. I'll get back on if i get stuck at any point! Thanks again.


Any more tips greatly appreciated!

[jamester_a]

My favorite brake post lives here (albeit for fronts..):

http://www.bmw-540i.com/1995-540i-brake-pad-rotor-replacement/index.php

Good luck,

- James

(And for goodness sakes don't run with the devil on the jack alone - Use jackstands and save yer noggin')



Any more tips greatly appreciated!

[Chris'91'525i]

Zeuk - thanks for the support, i'm hoping my tools are of a good enough quality toget these bolts out though! I don't have a torque wrench either so it'll have to be done F-T!

Ross - I'm using a haynes manual at the moment until i can me a Bentley, from this board i gather they're a LOT more useful?!!!!

Jeff N - I'm just wanting to do the pads, i'll leave the fluid for now... hopefully!!!! Thanks for the advice, i'll probably remove enough to leave a good inch at the top, do you think that'll be ok? On bruno's site it says watch that it doesn't go too low??

Shankster - Muchas gracias! I really appreciate your efforts there - I took a lot from it. I'm hoping to have a good look at it all tonight, and do them saturday morning. I'll get back on if i get stuck at any point! Thanks again.
Any more tips greatly appreciated!


You really should flush the brake fluid. I've noticed BMW's brake fluid tends to get to get nasty quick.


As for taking fluid out of the master cylinder when you push the piston back into the caliper, it is not necessary or recommended IMO.
I do take the all the fluid out of the MC, and refill it with fresh stuff before I do a complete flush though.

The Caliper has some of the most nasty fluid in the whole system and I don't like to push it back into the brake system.
What I do is put a small tube on the bleeder, and then in a small container before I crack it open. Open the bleeder and then compress the piston back into the caliper, most of the nasties go in the container. Close bleeder when piston is home. This makes for easier piston compression too.
I also use a line lock on the rubber caliper hose to prevent any fluid to back flow into the system, but it's not really needed if you don't want to get to anal on it.
When your done hit the brake petal a few times till petal is stiff, and top up master cylinder.

After doing above, I would at least flush a little fluid out of the calipers, till you can do a complete flush job.
For very large calipers check MC level after a couple pumps so you don't drop the MC level to low.

The best grease to use on caliper slide points and on the pads should have a high 'molydisulfide' content. It takes very high heat and it's the is best lube for metal to metal contact. (Also needed for transmission & clutch splines, throw out arms etc....)During use it actually goes into (burnished) into the metal. There like micro ball bearings.
Good stuff !!

[jamester_a]

+++++1 on getting rid of the nasty stuff this way and not forcing it back into the lines. Use a big C-clamp to compress.



The Caliper has some of the most nasty fluid in the whole system and I don't like to push it back into the brake system.
What I do is put a small tube on the bleeder, and then in a small container before I crack it open. Open the bleeder and then compress the piston back into the caliper, most of the nasties go in the container. Close bleeder when piston is home. This makes for easier piston compression too.

[e34.535i.sport]

Hey guys done the rears!!!! Piece of cake too, no problems at all (except for a little trouble witht the handbrake shoes holding the disc on the passenger side)!

Thanks for all the advice (unfortunately i have only just read your post on the nasty fluid, i will do this soon and a complete flush!).

Gutted because i just checked the front discs too and they have some wear issues and may need changing! ££££££££££££££££££££££££££....

Thanks again and i may do a write up myself on these (a dumbed down version for ppl like me!)

[e34.535i.sport]

I have these fun and games lined up soon, good luck and let us know how you get on! Have you priced up standard dealer parts with upgraded aftermarket ones? I wouldn't be surprised if they were about the same price. On my 535 a set of adjustable shocks (Spax i believe) were half the price of the replacement mtech ones from BMW and I had it on good advice that they were as good if not better and I got a good stainless Exhaust much cheaper than the BMW supplied one which would eventually need replacing anyway. Just a thought..

The front pads and discs from the dealer are £175 so may be looking elsewhere for these! On the plus side though changing them is easy so if you need help let me know! If i can do it, ANYONE can!!!!!!! :D

[filip00]

man, changing brakes is fun, it's just a dirty job.


*edit* - i see you're done, good job :)


you gotta have a good flat screwdriver so you could push the caliper from the disc, and release it....

you need a good pair of pliers to remove the caliper spring, and put it back after the job

the only potential problem is like someone said, a centering screw for the disc. when you DO remove it, you can, but don't have to put it back.

don't forget to get the brake pad indicators.

[BigKriss]

just do it

[e34.535i.sport]

Made up with hoe the brake job went, no real problems to speak of. Carrier bolts were ok to remove as were the caliper bolts and retaining screw.

Went for a bit of a test run last night to get a feel for the new brakes, and took it easy on them as the manufacturer (BMW) recommends. I put the anti-squeal paste on the back of the pads but i still have a very low squeal when braking - once i reach about 5-10mph as im stopping. Its really annoying! I'm thinking of removing the pads again and putting more paste on...

Any advice?

[filip00]

dude, take it easy...it takes a while for the pads to break in.

[Ferret]

dude, take it easy...it takes a while for the pads to break in.

Yeah, mine squealed for a little bit as the pads bedded in - they're perfectly silent now :)

[e34.535i.sport]

Thats good to know, i'll see how it goes then. The satisfaction i'm getting after doing them myself is amazing though!

[Ferret]

Thats good to know, i'll see how it goes then. The satisfaction i'm getting after doing them myself is amazing though!

Ha, yeah having done work like this yourself gives you some good satisfaction. :D

Especially when you realise the money you've just saved yourself :p

[e34.535i.sport]

I went for quotes on getting the rears done - cheapest was £216 all in using non-manufacturer parts. I bought the parts from BMW for £107 and done it with a friend... Now thats a BIG saving!!!!!

[e34.535i.sport]

I still seems to have a whistle sometimes after a few hundred miles just as i'm coming to a stop, I think i'm gonna take them off and re-copper grease the backs and carrier contact points. Marvelous!!!! :p