the car finally feels like it should.

I took the car to the dealer recently for VANOS, ne DSC, and rear door lock fix (all under CPO)

I also had them replace the bushings and do a 4 wheel alignmnent, and THEY said i needed new plugs, so they did that (total cost 600 bucks... OUCH)

BUT, no more ticking sound, and my wheel shimmy on acceleration was gone.
Then i had a bad shimmy when i hit the breaks... so i did my front breaks and rotors myself (not an easy job, like i thought) had to go buy all these damn tools which i didnt have which took a while... and the hex nut that hold the rotor was impossible to get out and i was worried about stripping it... so 2.5 hours later i was done (didnt do the rear)... the shimmy is gone and the car feels great

2 questions:
the BMW dealer told me that its very important to only tourque the lug-nuts to 85 ft/lbs which seems very loose, but he said that it how rotors get warped (by the over tightening of diff lug-nuts).

secondly, do i need to bleed my breaks or flush the fluid at all?

2 questions:
the BMW dealer told me that its very important to only tourque the lug-nuts to 85 ft/lbs which seems very loose, but he said that it how rotors get warped (by the over tightening of diff lug-nuts).

secondly, do i need to bleed my breaks or flush the fluid at all?

I don't have the specs, but those torque figures sound about right. And over-tightening CAN lead to rotor warping...

If you only changed pads and rotors, you generally don't need to bleed them. This assumes you did everything properly and didn't allow any air into the system.

When changing pads, one usually has to "push" the piston back into the caliper to allow room for the new, thicker pad. So, depending on how you did this, you may or may not have "compromised" the system. Also, you should flush (and bleed) your brake fluid every two years, as the fluid is hydroscopic (it absorbs water).

Sorry if this is already known, just trying to cover a few things.

i did have to push the caliper back in, all i did was open the break res cap... i doubt that introduced air in the system...

is bleeding/ flushing an easy DIY?
if not how much should i expect to pay

just curious how would water get into the system anyway?

i did have to push the caliper back in, all i did was open the break res cap... i doubt that introduced air in the system...

is bleeding/ flushing an easy DIY?
if not how much should i expect to pay

just curious how would water get into the system anyway?

You should be OK, given what you state...BTW, one trick is to have a dedicated turkey baster and remove most (not all) of the fluid in the reservoir before pushing the piston back in. This reduces the chance for brake fluid to overflow the reservoir and make a real mess...

I have not bled my E38 (did on my former E28, though). Given the right tools, it is a fairly easy DIY. Do a search here and you should be able to find what you need.

It's not exactly water that gets in, it's moisture (which sounds sort of redundant, I know). Basically, moisture can get past seals, around your reservoir cap, etc. The brake system is pretty well sealed, but it's not "moisture proof".

the BMW dealer told me that its very important to only tourque the lug-nuts to 85 ft/lbs which seems very loose, but he said that it how rotors get warped (by the over tightening of diff lug-nuts).

secondly, do i need to bleed my breaks or flush the fluid at all?

Most cars are torqued to 60 ft/lbs. BMW's recomendation is actually higher than average. Always install and remove lug nuts/bolts in a star pattern.

I generally inspect brake fluid at every pad change. If it looks cloudy, I flush it with clean fluid.

It's not exactly water that gets in, it's moisture (which sounds sort of redundant, I know). Basically, moisture can get past seals, around your reservoir cap, etc. The brake system is pretty well sealed, but it's not "moisture proof".

The fluid reservoir on the master cylinder may be vented to the atmosphere to avoid a pressure differential. I’m not sure. In any case, there is certainly some air at the top of the fluid. Air always has some level of humidity (moisture) in it and the brake fluid absorbs the moisture like a sponge.

Over time, more and more water is absorbed. This wrecks havoc with sensitive parts because it reacts with any iron or steel parts and rusts. I have seen calipers that are nearly full of rust material. Additionally, the boiling point of the fluid gets lower as the fluid absorbs water. In an emergency situation this water can boil into steam. Steam is a gas, and unlike liquids, steam can be compressed. The brake pressure ends up compressing the gas bubbles instead of pressing the pads against the rotors.

The best way to avoid this is to flush out the old fluid and replace it once every year or two.