|
I agree with your mechanic's comments.
I don't think it is a stuck caliper only because if it was stuck it wouldn't unstick so regularly.
First, resolve the sticking caliper concern. This isn't anything specific to the X5, more just a general procedure. Keep the wheels on. Get someone to sit in the driver's seat. Jack up the car, both sides. Use jackstands. Make sure the wheels spin freely. Have someone apply the brakes slowly, until one wheel is dragging. Freeze the pedal there. Spin the other side and see if the drag is similar. Now do it in reverse, starting on the other side of the car. Push the brake on hard, and make sure both wheels lock up. Release the brake pedal, and make sure both wheels spin freely. End of test.
If that doesn't point to a problem, move to bleeding. First lesson is to always keep the reserve topped up. Check it regularly during the bleeding process. You want to avoid getting air in the system.
Work on one wheel at a time. I would use a hose from the bleeder nipple and a clean pop bottle with several inches of brake fluid in it, with the hose end below the fluid level, but you can do it without that if you open and close the bleeder with every stroke of the brake pedal. Have a cooperative, attentive, helper in the driver seat. Call out your request for pedal up, pedal down, etc, and have them confirm each pedal stroke. It is slow and boring, but attention to detail pays off.
After all this, test drive the car. Make sure it is all buttoned back up, the brake reservoir cap is on, etc. Test the brakes before getting to the street. Once you determine everything is working, test them with a slow application, a hard application, and a so on. Bed them in if you like, but bedding in won't have much to do with your clunk, just with brake pedal feel.
Hope all that helps. I admire your determination. You do want to make sure that you don't let air get in the ABS controller. If you do, no handheld checker will help you, save your money. You would actually need the BMW computer that actively cycles the ABS valves to purge the air, you are not just clearing codes out to resolve that problem. Last price I saw posted on here was in the order of $500 to fix that problem, IIRC.
Good luck, and let us know how it works out.
Jeff
__________________
2007 X3 3.0si, 6 MT, Premium, White
Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue
|