97 850 brake noise

2forty · Post by **2forty** » 06 Jan 2018, 16:09

My 97 850 needs the ABS module which I have not replaced yet. When I brake hard it makes a grinding noise like my pads are bad. I removed both front pads which are worn but still good, cleaned the pads, rotors and calipers and reinstalled. Still makes the noise so my question is before I go to the expense of purchasing new pads, can the ABS system cause the noise when I brake hard?

Post by **scot850** » 06 Jan 2018, 17:26

I don't think this is the ABS unit (anything is possible). Sounds more like a seized piston or caliper. Have you also checked the rear pads as well? The rear calipers are more prone to seizing.

Remove the front pads and have someone press the brake pedal slowly and see if the piston comes out smoothly or hangs. Don't let it come out too far or you will have the piston come out. I usually use a piece of wood to prevent it being able to extend too far.

Neil.

Post by **jtp** » 06 Jan 2018, 18:29

I’d check the rear pads and rotors as well. Sometimes sounds move around on a car in funny ways. And it pretty much has to be the friction components based on the description (i.e not the ABS system).

2forty · Post by **2forty** » 06 Jan 2018, 19:45

I did check the rear pads and they were fine. I will check the calipers. Here is one more issues I did not mention. When I tested the brake making a hard stop it took a few seconds before the front brakes became free. Seemed like they were stuck locked for just a few seconds before I could go or it would make a clunking noise. Slow stops are fine, Only makes the noise on hard stops.

Post by **jtp** » 06 Jan 2018, 20:21

That makes it sound like a caliper sticking, I’d do Scot850’s diag above