Brake Calipers Seizing on 2003 Alpina Z8

[Polar993]

I have a 2003 Alpina Z8 Roadster with 17,000 miles. The car was purchased in 2008 with 9,000 miles and the car has been well maintained since my ownership.

Two years ago I took the car out for a drive and the brakes started to engage. The car wasn't rolling freely and after about 1 mile, the brakes were seizing so badly that I couldn't even drive the car. I had the car towed to my independent mechanic and he told me that the brake fluid in the lines was beginning to solidify. The consistency of the fluid was of a thin gel, not liquid. He cleared all the brake lines, but the front calipers on the car needed to be replaced, along with pads and rotors. Total repair job was about $4k!

This past weekend I had the car out at a car show in Bridgehampton, NY (The Bridge) and I had the car trailered out there from my home. About 3 miles into my drive, the same problem with my brakes started happening again! The brakes started applying and I felt increasing resistance. I pulled into a parking lot and called my mechanic. He said that perhaps the brake fluid may have again gone bad. I was surprised because I only had put about 400 miles on the car since the last brake repair and I store the car in a conditioned garage. None of my other infrequently operated cars seem to have this problem.

While I waited for a flatbed to come tow the car to my mechanic, I started pumping the brakes while the car was running and in park. I felt the brake pedal pressure begin to change and I put the car in drive and the calipers had actually released! I put the car back in park and pumped the brakes a few more times. The car became drivable and I bedded the brakes a few times with some abrupt stops, trying to get the brake fluid flowing normally and trying to make sure the calipers weren't sticking.

The car ended up driving very normal after this and at this point I'm not really sure what was wrong with it. I haven't brought the car to my mechanic yet, but he thinks the master slave may be faulty, or the type of BMW brake fluid he used may not be good for a car that doesn't frequently get driven.

Do you guys have any idea what may be wrong with my brakes? I'm now a bit nervous to take the car out as I don't know if I will run into this problem again. Each time I drive it, once it warms up I am now pumping the brakes a few times just in case. I don't know if this is doing anything to help, but the problem hasn't come back yet.

Any advice you can provide would be appreciated! I am a new member to the forum and I love my Alpina Z8 (352/555).

Below is a photo from The Bridge. Great show if you've never been.

Thanks!

[macfly]

That's the first time I've heard of this, so it could be a faulty master cylinder, but honestly I'm no mechanic, so just guessing.

[GaZ8fan]

Did you drive the car at all between the time you had the brake fluid flushed two years ago and this latest episode? If not it doesn’t surprise me that the calipers are getting gummed up.

[Polar993]

Did you drive the car at all between the time you had the brake fluid flushed two years ago and this latest episode? If not it doesn’t surprise me that the calipers are getting gummed up.

Yes, I did drive the car a bit during that two year time period after the brake lines were flushed. I put about 400 miles on the car over that time period and drove the car every 3-4 months.

Should I try a different type of brake fluid? Perhaps one that is less susceptible to gumming up?

If any of you have any recommendations for a good brake fluid, please let me know.

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[Polar993]

That's the first time I've heard of this, so it could be a faulty master cylinder, but honestly I'm no mechanic, so just guessing.

Hiw can I determine if the master cylinder needs replacing?

[GaZ8fan]

Yes, I did drive the car a bit during that two year time period after the brake lines were flushed. I put about 400 miles on the car over that time period and drove the car every 3-4 months.

Should I try a different type of brake fluid? Perhaps one that is less susceptible to gumming up?

If any of you have any recommendations for a good brake fluid, please let me know.

- - - Updated - - -

I would check your master cylinder then. The rubber seals in the master cylinder can break down and contaminate the brake fluid. A failing master cylinder will also give you inconsistent pedal feel.

[Polar993]

Thanks guys. I'll report back once I have a chance to bring the car in for service.

[llioz]

I was at The Bridge with the silver Z8. It was a fantastic event. Our cars looked great.Hope you get the brake problem sorted out.Larry

[Polar993]

I was at The Bridge with the silver Z8. It was a fantastic event. Our cars looked great.Hope you get the brake problem sorted out.Larry

Hey Larry!

Great to meet you last Saturday. Our cars did indeed look amazing at The Bridge!

Attached is one of my photos featuring our cars.

[macfly]

Stunning, they really are such photogenic cars!