I don't see why I can't do this myself - replace the pads and rotors (both fronts and backs) on my 1990 E30. I own literally NO tools, other than a jack and the stuff in the kit in the trunk of the car. Any idea what other stuff I'd need to do this job right or should I just suck it up and pay the $800 I've been quoted for the job?
tools / work required to replace e30 brakes
- Thread starter SparkyNT
- Start date
Do the rotors actually need doing? Pads is a 30min job for all four. Rotors about same again.
For pads you will need a decent 19mm (might be 17mm can't remember) socket or spanner with good leverage as the bolts are tight. That's to remove the entire caliper. The better way though is to use an allen key (not sure what size) to just remove one of the outer caliper bolts and hinge it out to get the pads out. I've also come accross one where the bolts were female torx head, not femal hex (allen) head.
In othe rwords not much.
To remove rotors you WILL need the spanner/socket and remove the caliper completely. The rotors are only held in place by a small allen/hex head bolt. Their weight is taken by the wheel studs which go trough the rotor into the hub.
Don't forget to bed the pads/rotors in afterward. Also if you have access to a torque wrench, torque the bolts up to correct spec - not all of them should be FT. Also, if you go by-the-book you should replace the bolts on the outer caliper as they are once-use. I never have and have been fine so far...
Use WD40 on the hex bolt as the head cams out easily and once rounded-off you'll never get it out.
Pretty easy really
For pads you will need a decent 19mm (might be 17mm can't remember) socket or spanner with good leverage as the bolts are tight. That's to remove the entire caliper. The better way though is to use an allen key (not sure what size) to just remove one of the outer caliper bolts and hinge it out to get the pads out. I've also come accross one where the bolts were female torx head, not femal hex (allen) head.
In othe rwords not much.
To remove rotors you WILL need the spanner/socket and remove the caliper completely. The rotors are only held in place by a small allen/hex head bolt. Their weight is taken by the wheel studs which go trough the rotor into the hub.
Don't forget to bed the pads/rotors in afterward. Also if you have access to a torque wrench, torque the bolts up to correct spec - not all of them should be FT. Also, if you go by-the-book you should replace the bolts on the outer caliper as they are once-use. I never have and have been fine so far...
Use WD40 on the hex bolt as the head cams out easily and once rounded-off you'll never get it out.
Pretty easy really
You should not turn BMW rotors, they are designed to be thrown away, one reason the price is so low. See this article from Koala Motorsports: http://www.koalamotorsport.com/article-replacingpadsandrotors.asp
They say not to do it as it "almost always results in rotors that are below minimum thickness and will warp in weeks" Which is why you only machine them to minimum spec.
Bentley recommends it aswell.
I have done it on all my cars and I drive them all hard. I've stress-cracked pads from overheating, but never warped a rotor.
Bentley recommends it aswell.
I have done it on all my cars and I drive them all hard. I've stress-cracked pads from overheating, but never warped a rotor.
17mm socket to remove wheels (comes with the car) and to remove caliper bracket.
5mm (or 5.5mm) allen key to remove rotor from hub
10mm (I think) allen key to remove caliper from bracket
re-grease the sliding bolts (floating caliper bolts)
anti squeek goop on the back of the pads
anti-seize on all the bolts
Torgue wrench (absolutely!)
That's about it... easy job... I've got it down to an hour now for all 4 wheels... done them way too many times...
$800 is way too much, parts should only be $300-400... + labor= 1 hour. $500 total at most.
5mm (or 5.5mm) allen key to remove rotor from hub
10mm (I think) allen key to remove caliper from bracket
re-grease the sliding bolts (floating caliper bolts)
anti squeek goop on the back of the pads
anti-seize on all the bolts
Torgue wrench (absolutely!)
That's about it... easy job... I've got it down to an hour now for all 4 wheels... done them way too many times...
$800 is way too much, parts should only be $300-400... + labor= 1 hour. $500 total at most.
They say not to do it because BMW rotors are soft and designed to wear, increasing braking ability, and reducing the thickness to a government mandated standard is unsafe as they can crack and fail. Besides they are only about $40.00 ea. rears, $30.00 fronts.
This from Koala Motorsports, a highly reputable BMW experienced tuners, "It is not recommended that you have BMW rotors cut, this almost always results in rotors that are either below minimum thickness or that will warp within weeks."
Lets be honest, this is what the Bentely tech said about BMW rotors and he was referring to a person complaining about "shimmy" while braking, "You need most likely new front brake rotors. Turning the rotors will help, but only for a couple of thousand miles." Not a recommendation for turning rotors, simply a quick cheap temporary fix.
From The BMW Brake FAQ
by Steven Jay Bernstein, BMWCCA #83901
"Why can't I simply turn the rotors?
Warped rotors cannot be turned (cut). The excessive heat that has caused the rotors to warp changes the composition of the metal so that they cannot be cut properly, and the problem returns virtually immediately. New rotors from a BMW dealer, with a BMW CCA discount, are so inexpensive, particularly on the older BMWs, that it is economically foolish to turn old ones.
Another comment on turning rotors - when you buy new rotors from BMW, they have a coating on the brake surfaces. Clean them before installation. Take some brake cleaner and clean off both surfaces of the rotor (where the pads make contact). Then, upon assembly, don't touch the surfaces with your greasy hands."
BMW Z4 rotors for example start out at 22mm thickness and the minimum allowed before discard is 20.4, not a lot of room for turning.
This from Koala Motorsports, a highly reputable BMW experienced tuners, "It is not recommended that you have BMW rotors cut, this almost always results in rotors that are either below minimum thickness or that will warp within weeks."
Lets be honest, this is what the Bentely tech said about BMW rotors and he was referring to a person complaining about "shimmy" while braking, "You need most likely new front brake rotors. Turning the rotors will help, but only for a couple of thousand miles." Not a recommendation for turning rotors, simply a quick cheap temporary fix.
From The BMW Brake FAQ
by Steven Jay Bernstein, BMWCCA #83901
"Why can't I simply turn the rotors?
Warped rotors cannot be turned (cut). The excessive heat that has caused the rotors to warp changes the composition of the metal so that they cannot be cut properly, and the problem returns virtually immediately. New rotors from a BMW dealer, with a BMW CCA discount, are so inexpensive, particularly on the older BMWs, that it is economically foolish to turn old ones.
Another comment on turning rotors - when you buy new rotors from BMW, they have a coating on the brake surfaces. Clean them before installation. Take some brake cleaner and clean off both surfaces of the rotor (where the pads make contact). Then, upon assembly, don't touch the surfaces with your greasy hands."
BMW Z4 rotors for example start out at 22mm thickness and the minimum allowed before discard is 20.4, not a lot of room for turning.
OK. I wasn't referring to warped rotors, but rotors that have a small lip. The minimum thickness is not "some government mandated spec" but the spec provided by BMW. I figure it is BMW provided as the machinist that turns mine gets a book full of min thicknesses for every model car and it matches exactly to the minimum thickness specified in the Bentley manual.
I hear what you are saying about rotors being cheap in the US, and so there is no compelling reason to machine the rotors. And that applies to the original question, but in NZ where our parts typically cost twice as much as they do in the US, it is cheaper and perfectly OK to machine them to remove the lip. If they are warped, then sure, buy new rotors.
I hear what you are saying about rotors being cheap in the US, and so there is no compelling reason to machine the rotors. And that applies to the original question, but in NZ where our parts typically cost twice as much as they do in the US, it is cheaper and perfectly OK to machine them to remove the lip. If they are warped, then sure, buy new rotors.
Removing a lip is not really "turning" the rotor, you are not removing anything that the pad has not already removed. In your sense of the term, Ok I can live with that, remove the lip. However I believe that 99% of the mechanics and DIY'ers are going to interrupt "turning" a rotor as machining the entire surface.
BMW does not mandate the minimum thickness of a rotor, it is determined by the manufacturer of the rotor. Here in the US he does this because he is legally required to do so (I would calll that a mandate by the government, but iit is the maker who makes the determnation. (I stand corrected)
BMW does not mandate the minimum thickness of a rotor, it is determined by the manufacturer of the rotor. Here in the US he does this because he is legally required to do so (I would calll that a mandate by the government, but iit is the maker who makes the determnation. (I stand corrected)