seized brake caliper?

[lecourasa]

I have a 2001 330i (e46) with about 220k miles. Replaced the brake pads and rotors a couple of months ago. Bleed and replaced fluid too. Last week I started noticing that it started getting sluggish. Its a manual and I typically coast a lot and I noticed it was slowing down as if I was pressing the brakes, but I wasn't. Got home checked each wheel and noticed the the right front rotor was very hot compared to other 3. Next day seemed fine at first but problem came back during 4 mile drive to work. Basically, what happens now is once I step on the brakes, right front is locked in. If I park for a while it frees up again. Seized caliper, right?

If so, what is the fix? Replace the caliper? As I mentioned, pads and rotors are brand new. Will I need to replace them too? How can I tell?

I should mention that when I replaced the pads and rotors I had a hell of a time getting that right front on. Caliper piston wouldn't quite compress enough. Just needed to go in another millimeter, if that. With enough force eventually got it to go that extra millimeter. I guess that should have been a sure sign of trouble ahead...

Thank you in advance for your help and input.
Alexis

[bmwdirtracer]

Hi Alexis,
Diagnosis: Lift that corner of the car. Does the wheel spin? If so, press the brake pedal fairly hard. I'm going to assume that the wheel does not spin easily. Now, crack open the bleed screw at that wheel. Does the wheel (or rotor, if you took the wheel off) spin easily? If so, replace the brake hose to that caliper, and the caliper on the other side too. If the rotor does not spin easily after opening the bleed screw, replace or rebuild the caliper. (You can generally buy rebuilt calipers for ~$50)

Yes, you should also replace the rotors and pads. That rotor will have been overheated immensely, same with the pads. The pads on that corner will likely be very worn, too.

[02Pilot]

I've also seen - albeit rarely on cars this new - internal failure of the soft brake line. It swells up, blocking the return flow of fluid and holding pressure in the caliper. I suspect your problem is simply a frozen caliper, which is much more common, but if the piston moves easily when removed from the car the line may be a factor.

[lecourasa]

Mmmm. I would not have thought of the brake line. I'm glad I posted here. I will diagnose tonight and let you know what I find out.
Thanks,
Alexis

[bmwdirtracer]

Just to clarify: My post was a tiny bit unclear. When I said "if the wheel turns easily after opening the bleed screw, replace the hose to that caliper, and the caliper on the other side too", I really meant "replace both hoses" (NOT the caliper on the other side....the HOSE to the other caliper.)

By the way, NEVER hang a caliper by the hose - that's the most common cause of internal hose failure.

[lecourasa]

Just to clarify: My post was a tiny bit unclear. When I said "if the wheel turns easily after opening the bleed screw, replace the hose to that caliper, and the caliper on the other side too", I really meant "replace both hoses" (NOT the caliper on the other side....the HOSE to the other caliper.)

By the way, NEVER hang a caliper by the hose - that's the most common cause of internal hose failure.

Yeah, I used a bungee cord to suspend the caliper from the spring when I was changing out the pads & rotors. And I picked up on the typo. I was going to wait to clarify if it turned out to be the brake line, which its not. Cracking open the bleed screw made no difference. Rotor is still locked tight so I guess its the caliper that needs to be replaced. Called local dealership and was surprised when they told me they wanted $380 for a caliper. Did find a remanufactured one online made by NuGeon for $55. Anyone have good or bad experience with them?

Also, should I replace the hose from the body to the caliper as a preventative move? If so, should I replace with stainless steel line?

Rotor is blue, so I guess its toast. Pads still look barely worn so I was thinking of keeping them.

Thanks,
Alexis

[bmwdirtracer]

If the car were mine, I'd buy the rebuilt caliper, two new rotors and new pads, and two new hoses. Stainless hoses are very nice; a set of 6 will cost maybe $100. Stock hoses maybe $10-20 each.

I personally never fit one rotor at a time.

[MIKYZZ4]

Here is a decent option:FRONT
https://www.fcpeuro.com/products/bmw...akebono-330bk3

Complete option:FRONT & REAR
https://www.fcpeuro.com/products/bmw...i-330xi-330bk4