Alfa 159 brakes sticking on (heavy braking)

Tea drinker

Brakes locking on when heavily applied, and do not release.
Brake master cylinder has been replaced.
Brakes still stick on. Could be a rear caliper, then 2 taps of the pedal and it releases. Hard application of the brakes and the opposite side front caliper locks.
garage suspect the ABS Pump / Module now.

Any thoughts? Not my car, it's my friends

biko

Possibly the pads not sliding well in the calipers - this would be the first thing they look at so is probably not the culprit.

Old and worn brake hoses can deteriorate inside which can hinder back flow.
Is car old?
Inspect the hoses, if they look crap outside they are crap inside.

Tropheus

You should also check the pistons to make sure they're not seizing. You may have to bit the bullet and replace the rear calipers.

Hellrazer

Calipers were common to go on the 159s.
First thing Id be looking at.

Tea drinker

Hellrazer wrote: »

Calipers were common to go on the 159s.
First thing Id be looking at.

Hmmm what is the remedy, new slide pins or the caliper itself the pistons and seals need a rebuild? Sheesh those Brembo calipers $$$ :-)

biko

Who changed the master cylinder?
Does your friend know brakes?
Would they have checked pins etc already?

Tea drinker

biko wrote: »

Who changed the master cylinder?
Does your friend know brakes?
Would they have checked pins etc already?

Reputable garage, he's a long standing customer. Friend is not so mechanical tbh.
I think changing the master cylinder fixed some issues with soft pedal and loss of pressure so it was a good call, no issue around competence in the garage. Issue my buddy has is dropping 1800 - 2000 on a new ABS pump that's more than the cars worth, and that might not be the end of the problems either.

So we'll see, there's second hand ABS pump we might have a go at fitting, if he decides to go that direction.

Hellrazer

Tea drinker wrote: »

Hmmm what is the remedy, new slide pins or the caliper itself the pistons and seals need a rebuild? Sheesh those Brembo calipers $$$ :-)

Caliper itself. Dont think they were that expensive from alfa for an exchange unit.

sergebud

@Tea drinker

Did you end up getting sorted?

Currently have the exact same issue and it's driving me insane.

My dragging is a bit more pronounced until I restart the car after sitting for a bit.

Can only barely feather the brakes or they start seizing.

Also have the issue where the lock changes left to right after heavy braking.

Any help would be greatly appreciated.

Kind regards

Serge

10-10-20

Hoses would be my first port-of-call here. I had two do this to me in quick succession on an Alfa 145. Took a few attempts to identify the culprit, but ended up being that the hoses had collapsed and would allow high-pressure fluid into the brake piston, but it didn't have sufficient pressure to return; hence they stuck on. Hope it helps.

sergebud

I've 4 hoses bought there,

This is the second 159 I've owned that has done the exact same thing but I'm determined not to let this one beat me.

I will update with progress once we get around to that job.

sergebud

Hoses done, thought everything was great until I drove it in heavy rain and the ABS kicked on.

Back to square 1, leading me to blame the ABS pump...

Nightmare

extra-ordinary_

https://www.boards.ie/discussion/comment/121962694#Comment_121962694

ABS or brake pressure sensor, could hardly be caliper related if they all lock at different times.