Seized Callipers? - How to Diagnose?

[msportpanda]

I've left my Z4M sitting for a few months and noticed the front left brakes are quite hot and squeaking at low speeds.

I assume this is a seized calliper, can this happen from letting a car sit for an extended period of time?

Before I go ahead and replace both front callipers, are there any quick or easy wins that I can try as a DIY solution?

Also noted that since I've owned the car, the brake pedal can be pushed to the floor with the engine on, could this point to a slow failure elsewhere, perhaps a master cylinder issue?

Would like to try and diagnose it properly so I don't end up just chucking parts at the car so any guidance would be much appreciated.

[guards red]

First thing would be to see if it rolls easily back anf forth with the handbrake off.

[droopsnoot]

msportpanda said:

Also noted that since I've owned the car, the brake pedal can be pushed to the floor with the engine on, could this point to a slow failure elsewhere, perhaps a master cylinder issue?

Do you mean that if you sit with the engine running and the car stationary, then put your foot on the pedal, it goes to the floor? Or does it do it while you're actually braking? If the former, I'm not sure that's a fault with ABS systems, I seem to recall reading an article ages ago that suggested it's down to how the ABS works. I can't say I've ever tried it in the one car I've got with ABS, though.

[Far Cough]

guards red said:

First thing would be to see if it rolls easily back anf forth with the handbrake off.

On a similar vein. I'd be jacking up each corner and spinning the wheel making sure they rotate freely. You can also check for leaks whilst your down there.

[Belle427]

I can't explain why but I had a 2008 Saab 9-3 and when you kept pressure on the pedal with engine running it would slowly sink down.
Changed the master cylinder thinking it was that and it was still the same.
No leaks anywhere and no loss of braking performance.

[ARHarh]

First brakes can seize at any time, but saying that left unused for a while may cause them to seize.

As suggested lift the wheel and spin it you will soon notice if it is sticking. Do this for all wheels not just the one you suspect as any differences will be more noticeable that way.

Do the calipers have sliding pins, not sure they will or not. But the sliding pins are normally the first to seize.

Not sure about the brake pedal but if it really is going to the floor you need to get it fixed before driving it.

[Master Of Puppets]

Probably the most common problem in the garage here with brakes is the pads jammed solid in the carriers, then stuck slider pins, and
if it's not those it will be the caliper piston. Don't write off your calipers until you check the first two.

[msportpanda]

Thank you for the guidance everyone, really appreciate it. Will get the car up on stands tomorrow and check the pad carriers and slide pins before I go for a new calliper.