DIY: Cross Drilled Rotor Brake Install! StepByStep

Originally Posted by calialx1

Thanks for writing this, really helped me out today as I was doing my rears. Something i learned, if your fluid is near the max mark you might want to put a rag under the reservoir because some fluid will spill when you compress the calipers.

This is why you should not really be topping up your brake fluid at all.

As the pads wear, the fluid level will drop which is perfectly normal. When you compress the pistons, the level will rise, again normal. If you topped up the level when the pads were worn then the fluid will overflow if you don't remove some of it before hand.

The brake system is a sealed system therefore no top ups are needed unless you have a leak in which case the leak needs to be fixed rather than putting more fluid in the system.

Can you just replace the front pads without new rotors? My mechanic suggests i change both, but I don't know why.

-Dore

Originally Posted by dorem

Can you just replace the front pads without new rotors? My mechanic suggests i change both, but I don't know why.
-Dore

Assuming that your rotor thickness is within spec, you can replace pads without new rotors; BMW Dealerships do so regularly if it is warranty work. However, there are potential problems associated with keeping old rotors, even if they are within spec.

First, it is possible that the rotors will wear to well under spec without you knowing about it because you have fat new pads that won't require replacing for a while. Next, the rotor will have less mass and be less efficient at absorbing heat, potentially contributing to brake fade. Finally, the old rotor will have the old pad material bedded in and the old pad wear pattern, potentially reducing braking effectiveness and pad life span.

New rotors are relatively inexpensive and do not add to the labor of a brake job. They will likely improve your braking performance and be safer. BMW Dealerships recommend that you replace the rotors if they aren't the ones paying for it.

Is this DIY similar with Brembo BBK's?

Originally Posted by M Shark

Is this DIY similar with Brembo BBK's?

Similar, but not exact. I don't think that the Brembos will fit directly, they will come with adapters that allow the caliper to fit. There may be some other minor mods required. I think the pads will mount from the top, easier to get in and out. Heat shields will probably have to be trimmed for rear calipers.

Well, I already have a set of front and rear Brembo BBK installed. I was just wondering if replacing the rotors and pads would be similar to the DIY above. I think I might have to change out my break pads soon.

Originally Posted by M Shark

Well, I already have a set of front and rear Brembo BBK installed. I was just wondering if replacing the rotors and pads would be similar to the DIY above. I think I might have to change out my break pads soon.

No significant changes. Replacing the pads will be easier.

Has anyone had the inside of the allen/hex bolt on the rotor stripped out? I mean the hex female hole that accepts the allen wrench. I assume I can get a new one from dealer but how the efff do I get this old one out. Obviously it is in there pretty tight. i have applied some penetrating spray and will go buy a new #6 hex/allen socket and try one more time. Will I have to take it to a shop?

Drill it!

Originally Posted by bradalex

Has anyone had the inside of the allen/hex bolt on the rotor stripped out? I mean the hex female hole that accepts the allen wrench. I assume I can get a new one from dealer but how the efff do I get this old one out. Obviously it is in there pretty tight. i have applied some penetrating spray and will go buy a new #6 hex/allen socket and try one more time. Will I have to take it to a shop?

This shows you another option for removing the locator bolt without drilling

If you don't want to watch the video, you take a punch and a hammer and push in the sides of the stripped allen head enough that you can get the 6mm bit back in. The video also shows how to loosen them up before even putting a bit into it. If you don't have a brass punch, I found placing a 10mm deep socket up against the locator bolt, whacked a few good times with a BFH, loosens them up just as nicely. No PB Blaster / Liquid Wrench / WD40 spray required after that. Good luck!

Thanks for the links. The 3rd one on rear brake pad install also tells you how to reset the brake light on the dash. Turn the key two clicks with the door open and wait about 40 seconds. I replaced the rear pads and the sensor only as the disks had very little wear (52K miles on the car). It was interesting to note that the pads on the passenger side (where the sensor is) were worn down further than the drivers side.

Originally Posted by ddnmkun

Found this 3 diy video on youtube, they are all good demonstrations!!

Nice Forum!! Just finished the rear rotors. Heads up, you will need a 7mm allen wrench for the two bolts holding the caliper pieces together. Thank you!!

Nice DIY!! Just finished the rear rotors. Heads up, you will need a 7mm allen wrench for the two bolts holding the caliper pieces together. Thank you!!

this was a great help when i considered doing it myself. The only problem i experienced was the 16mm bold on the lower side of the caliper was difficult to get out given the amount of space to work with. so i bought a ratchet and made that a little easier. pushing the piston in to allow the new brake pads to fit in was a bit tricky as well. but the hardest by far was taking off that god for saken rotor!!! i must have hit that rotor 5,000 times with a hammer. I thought for sure i had messed something up. i even tried cutting through the whole rotor with an electric saw. finally i decided to put some heat on the rotor / hub, Got me a torch with a propane tank and went to work, as it got hotter i nticed it moving off the hub ever more slightly. after a good 20 minutes applying heat, the hub was glowing red. I banged it with the hammer for the 5,001 time and the rotor finally came off the hub. quite a site of relief. i thought that damn thing would never come off. Maybe mine was super stuck, but there has to be an easier way to get it out. anyways, i proceeded to finish replacing rotors and pads on the rear tires. everything went as planned and so far so good. the only thing i need is to connenct the new sensor sire because i got the light flash up on the dash.



thanks for the help. i got down and dirty but i did it myself thanks to the forumn. !!! and saved myself 275$

Originally Posted by Gomez_andres

this was a great help when i considered doing it myself. The only problem i experienced was the 16mm bold on the lower side of the caliper was difficult to get out given the amount of space to work with. so i bought a ratchet and made that a little easier. pushing the piston in to allow the new brake pads to fit in was a bit tricky as well. but the hardest by far was taking off that god for saken rotor!!! i must have hit that rotor 5,000 times with a hammer. I thought for sure i had messed something up. i even tried cutting through the whole rotor with an electric saw. finally i decided to put some heat on the rotor / hub, Got me a torch with a propane tank and went to work, as it got hotter i nticed it moving off the hub ever more slightly. after a good 20 minutes applying heat, the hub was glowing red. I banged it with the hammer for the 5,001 time and the rotor finally came off the hub. quite a site of relief. i thought that damn thing would never come off. Maybe mine was super stuck, but there has to be an easier way to get it out. anyways, i proceeded to finish replacing rotors and pads on the rear tires. everything went as planned and so far so good. the only thing i need is to connenct the new sensor sire because i got the light flash up on the dash.



thanks for the help. i got down and dirty but i did it myself thanks to the forumn. !!! and saved myself 275$

Dead blow hammer on the back of the rotor usually gets it off. Just keep turning the rotor and hitting it. Usually takes a few minutes of banging.

Lost some pics, can it be edited back with all pics?

Do the caliper slide pins need any lube?

could used it

Where did you find these rotors? I'm having the hardest time finding zimmerman coated x-drilled rotors, the front can be found everywhere, but I haven found any zimmermans that are drilled and coated for the rear

Did my brakes this past weekend. As a teenager I owned a Fiat 124 and Alpha Romeo Spider and changed pads/rotors on them but that was long ago. Read lots/watched lots of DIYs including this one before starting. Here are a few random tips I gathered that may (or may not) be helpful:

Pay the $13 for a 6 inch C-clamp to compress the caliper piston, much easier than what is suggested in this DIY.
Dirty job, get a pair of rubber gloves.
Buy the large can of brake cleaner, you'll need it....
and, combined with wire brush, clean the caliper holder well. It makes everything easier to re-assemble.
Fine steel wool and the brake cleaner does a great job cleaning the caliper guides.
Heavy steel wool good for caliper spring.
Pizza box a good surface to clean parts on. Plus, you get a pizza.
I liked the DIY at http://www.bmw330ci.net/ the best. Good photos and tips and includes torque settings and brake bedding reco too.
To get rust off the hub, WD40 + wire brush. I then used brake cleaner to get all grease and grime off then......
Anti-seize the hub before putting the rotor back on.
Allen sockets (6 and 7 mm) much easier to use than allen wrenches.
12 or 18 inch socket breaker bar very helpful to get the 16 mm bolts out to remove caliper holder.
I followed the anti-squeal reco exactly and no squealing at all.
Only put the inside pad into the caliper when putting back together. Hold the outside pad on the rotor (within the caliper bracket) and slide the caliper/inside pad around the rotor and outside pad.
As suggested in this thread, loosen the fluid reservoir cap so no air gets in lines when piston compressed.
I ordered all my parts from BMAparts as they had good selection, great prices and free shipping Google "BMAparts discount code" to save additional 5%. The code was "specE30" when I ordered but I don't know if the code stays the same.

First wheel took me 5 hours to complete because of multiple return tips to Ace hardware for tools I didn't think I'd need (allen sockets, breaker bar, C-clamp). Each wheel thereafter took about 1.25-1.5 hours as I probably spent more that usual time cleaning parts. I figured I would not be doing this again for several years so I took extra time.

Good luck to all on this DIY! I figured I saved $550-700 doing this myself. The satisfaction of a job well done.........priceless.