Sigh . . . . Left Front Brake sticking . . .again

[chedeng]

Replaced both front brake rotors and pads Apr 2017.


Brake sticking started happening Feb 2018. I replaced caliper with a remanufactured BMW caliper and that’s including the carrier bracket.


Today, July 20, 2018, sticking again. I measured the left side 260F and right side is only 107F.


The side that is having problem, the rim is too hot to touch. The other three corners are fine. It is only the left front having the issue.


Plan: I will be replacing the rotors and pads with a better brand this time (I used Centric) and will be bleeding and changing the brake hose again.


P.S. X5 is driven 90 miles / day all HWY driving. Current rotors/pads setup has 17K on it.


Just Venting . . .

[Scott ZHP]

I'd replace the brake hose.

They can collapse internally preventing fluid from exiting the caliper when the seal contracts the piston.

[andrewwynn]

I've done a few brake jobs recently. Several had very crusty guide pins. You may just need to clean things up. The hose worth looking into at the same time.

[upallnight]

Are you greasing the guide pins? BMW advise installing the guide pin DRY. If the guide pins are rusty, the rubber boot has been compromised. You need to replace the rubber boot and guide pins.

[andrewwynn]

Not greasing per se. Just cleaning /polish. (Spin in a drill/ green scrubbie with some oil). Wipe clean but don't degrease. Just the slightest wd-40 to keep from rusting not enough to collect dust.

It was a Volvo that had the rust pins. My X5 just was not perfectly clean so I polished them. Correct on if they are rusty boot needs replacement.

[kevinkay]

I had same issue - replaced sticking caliper with "re-manufactured" (and new rubber hose) and exactly the same issue - was getting SO much hotter and wearing out the pad faster than the other side.
I replaced it with NEW BMW caliper and rebuilt the other 3 .

There is a theory that once a caliper gets "cooked" its shot - I think thats true

[cn90]

- I usually rebuild the caliper myself using new boot and seal (ATE or FTE).

- Brake Hose: yes replace them (use only ATE or FTE etc.).

- Guide pin: clean with steel wool: Honda says grease it, BMW says do not. Who cares, just clean it and apply a tiny bit of grease. It gets dirty anyway with road debris etc. Once every 3-4y, clean the guide pins.

[BMW_E53]

My front passenger caliper was sticking and caused uneven wear between the front driver and passenger pads about two years ago. What I did was rebuild my caliper using new boot and seals and did a complete brake fluid flush. Try that and make sure your guide pins are clean and see if that helps. If problem still persists then you may need a new brake hose.

[chedeng]

All,

I appreciate all the tips/comments provided.

I finally had a chance to look into this problem this past weekend. I removed the caliper and saw the rubber boot that protects the piston came off a little bit (maybe an inch). Who knows it could be the cause of the problem.

I got a warranty replacement from Autozone and got a brand new (remanufactured) caliper again at no cost.

• This time, I did not grease the pins. There was a very light coat on the pins from the rebuild so I left them alone.
• I make sure the reservoir brake level is between the min/max mark. I must have overfilled last time I bled the brakes.
• The rotor does not even have a lip so it was not replaced.
• The pad is still good and no glazing. I wire wheel the pad.
• Hose was replaced this past Feb 2018 so it was not replaced at this time.

So far so good after about 100miles. I will continue to monitor using infrared thermometer and temperature seems to be staying around 160F (front) after a long drive. Only time will tell.

Here is a pix of the remanufactured caliper: