thanks really appreciated this cant wait to try it out

 

Hi guys, sorry it took me so long to reply again. The problem hasn't been solved yet, but it's become a minor annoyance compared to the other problem the car has now. In short the car was pushing its cooling fluid out of the reservoir, what first seemed to be the thermostat that was stuck close, turned out to be a cracked engine block (between cilinder 2 and 3). Because the car is worth scrap value without its engine, it's now with BMW for an engine swap (7000mls salvage engine from a 120d that ran under a trailer). The 'new' engine had been given the timing chain treatment as a precaution so at least I have that less to worry about (that and a stack of money).

and thanks Bimmerfan52 for the guide. I did already find this guide and I used it to bed in the new rotors.

@e6t lab rat I did measure the old pads but they were the same thickness, so no new information there.

As the car was standing in the BMW workshop anyway, I asked them to take a look at it, I'll post any new information here.


grts,
Tom

 

I have the car back now. They did a few diagnostic tests in an attempt to determine the problem, but didn't come up with a solution. Their first action would be to replace the rotors and pads and see what happens

They measured the rotors and there's a 0,020mm deviation on only the outside face of the rotor, 0,012 is the maximum allowed.
They had the car on the brake tester to see if the calipers stick, they tested with cold and hot brakes but the readings didn't show anything wrong.

So the saga continues. As it's only the outside of the rotors that's warped, it seems to mee that it has to be from excessive heat on the outside face of the rotor due to the pads that keep rubbing on that side.

My next move will be to rebuild the calipers, and install new slider pins. Keep your fingers crossed.

 

I would suggest replacing both front wheel bearing/hub assemblies. They are integrated bolt in (not pressed in) units on rwd e60's and should be an easy diy job. Do this and then replaced your rotors.

 

I am sure I read somewhere BMW does not recommend applying anything between the hub and the flange, install the rotor completely dry, no anti seize or heat conducting grease.

 

Any experience with untrue running bearing/hub assemblies? Is this a common thing?
Wouldn't there be a noticeable slack on the bearings?

I'd like to be able to check this before investing in a set of new hub assemblies.

They do, with the last new set of rotors and pads I installed them with clean hubs, sanded them until they were completely smooth.

 

I wouldn't say its common, but in cases where replacement rotors become warped again, the bearing replacement has corrected the issue.

 

Dial indicator would verify if you have bad hubs

 

FWIW...I had the EXACT same problem, with same symptoms. I replaced my front calipers, as I suspected one sticking caliper. While I was at it, I replaced the stock brake lines with braided SS lines...and the judder/shudder problem has been gone for over 20K miles (which is >6mos in my world). My brakes are FREAKING AWESOME ever since....minus the dust, as I prefer OEM pads.

 

Did you notice excessive heating of your rotors, or do you reckon they were just mildly sticking? At BMW they tested my brakes cold and hot to see if there was any drag while the brakes weren't being applied, but that wasn't the case. Did your front rotors warp on both sides or only on one?