What's going on all, hope all is well as everyone gets ready for thanks giving. Recently I've encountered a strange problem with my disco, when I depress the brakes going slowly it makes a low thumping noise, kind of like a bass kick. For a few days I thought It was coming from under the car, until I tried just starting the car in the driveway, and when I lightly push them it makes the noise, but it's never sustained or intermittent, just one thumping subwooferesque sound when I depress the pedal initially. This doesn't usually happen at normal highway speeds.

Coincidentally I'm also getting a slight squeak from my brakes since this started when I'm coming to a slow stop. Again, it doesn't happen when I'm going normal speeds, but when going slowly there's a certain pressure that can make the brakes squeak, any lighter or harder and the noise stops. I've changed and bleeds the brakes within the past month or two, a long with a majority of the other 60k mile maintenance (mine has just over 62k), I'm wondering if it could possibly be a warped rotor maybe, and what signs should I be looking for?

Thanks all.

 

With limited info i'm leaning toward improperly secured and installed calliper / pad.

Try a little experiment with a helper to listen to each wheel, one at a time... with no one and nothing in front or behind you.

Keeping your left foot firmly on the brake pedal... with the trans in drive... if you give the gas pedal a little nudge do you hear any movement sounds coming from the hub / rotor area (clunking, clicking, clacking....or even a subwoofer bump)? repeat in reverse...

no ABS light on the dash right?

 

What I find strange is you are getting this while sitting still in the driveway?
No movement right?

If that is the case I would suspect a moving component attached to the pedal.
Such as the brake booster or the ABS module doing something strange.

I found out my front brakes were missing the securing pins for the pads and made noise as the pads tried to escape the calipers and hit the wheels. Talk about freaky.
remedied the pins missing and noise gone. Nice there is a safety net in case the pins go missing.

 

I removed the ABS fuse a few weeks back, so the light is on but there were no problems, it just felt as if the ABS was engaging sometimes when it wasn't so I removed it.

I will try that experiment, thanks cosmic.

Yea colo, I get the noise, but it doesn't happen when the car is off, only when the car is on (engine doesn't have to be running, but key has to be in position 2).

I hope my pins aren't missing, that would definitely be worrisome, I'll have to take a look, unfortunately, my jack and some of my tools were stolen out of our backyard and I've yet to replace them.

 

check the radius arm bushings. mine were shot causing the axle to twist under breaking and hit the radius arm, causing a low thump.

 

With the vehicle not needing to be in motion I doubt it is anything motion related.
Brings me back to brake booster or master cylinder or linkage on the brake pedal.

I recommend having someone push the pedal with the key on and move around and listen and touch things in the brake system to pin point the concern.

 

Thanks colo, thats my plan tomorrow, any suggestions on where to look. I'm gonna try to check brake lines, and everything, and I was thinking maybe warped rotor but I didn't really get any shimmying or shuddering while stopping and the slight screech I hear seems to be more related to when I'm driving slow and apply light pressure, which, if it was the rotor it would make a consistent noise regardless of my speed or applied pressure right?

I agree with you though, because it happens when I'm not moving it seems like its not motion related, but I DO think that the slight screeching I mentioned is linked to this, as I just changed my brakes about two months ago and they weren't making any noise or giving me any issues until I started hearing this about a week and a half ago.

Coincidentally, I didn't drive for a few days after surgery and it got cool and rained off and on here for the firet time in months, and thats about when I can recall that occurring.

Edit: left out something that could be huge, totally forgot, about a month back I changed both of my front wheel bearings, didn't do most of is myself had my mechanic come over and just helped him and learned. Although I'm certain he replaced everything properly, one thing we didn't do is switch that bendable lock nut, it was still good so we figured there was no point (plus I forgot to grab one). I just don't know how this would call this thumping, bass sounding noise only when I depress the pedal, not when I'm driving, but it might explain the slight screeching no?