severe groaning when braking

1996 Tacoma V6 Automatic

I'm not a car person, but so keep that in mind. I often get a groaning sound when braking downhill, beginning at the last few seconds of braking and lasting until the wheels stop. It's pretty loud and sounds like it's something large causing it, as if an axle is about to break. It feels like it must be something quite large to cause such a deep, reverberating groaning noise, if that makes sense. More than just a loose wheel, for example. I first noticed it 7 months ago, and only lately has it started up again. It happens both in forward and reverse, as long as it's moving downhill. It may have happened uphill or on level ground, but not that I can remember.

What should I look at? Let me know if I can provide more info.

 

Get your drums and rotors resurfaced or replaced and get new brake pads.

 

Toyota's pad and shoe compounds sacrifice noise for longevity. I squeal on some stops and groan on steep downhill offroad decents. The solution is a different shoe and pad compound, like a ceramic formulation.

 

I did take this to a shop a while back, and they couldn't find or fix the problem. But they didn't test drive it to hear it either. They ended up scuffing up the brakes a bit to increase friction to see if that helped.

I also had this work done:
- power steering fluid changed
- trans fluid changed
- clean rear brakes
- tighten rear brakes because parking brake was loose

I tried demonstrating the problem to a mechanic friend but somehow I couldn't get it to occur on the hills around his house. Keep in mind the noise happens just in the last instant as the truck comes near to a complete stop. The brakes perform well. I can extend the noise if ease off the brake to let it inch forward downhill. I can avoid the noise by keeping the truck moving more than an inch per second or so.

Perhaps a couple months before this started I had this work done:
- differential fluid changed
- rear shocks replaced
- front wheel bearings repacked
- alignment.
But I only noticed it happening one time perhaps a couple months later, and it didn't happen often until a few more months after that.

Could it have anything to do with the automatic transmission shifting into 1st gear? The shifting is smooth at all gears, so I'm not sure when it's shifting into 1st, and only a minor delay when I shift into park or reverse, the same as it's been since I got it 5 years ago.

I haven't tried a different compound on the shoes and pads yet. Would that still make sense based on the additional information in this post? I get a little squeal from the brakes too, but I'm not concerned about that. The noise I'm hearing is different.

I think I warped my rotors braking hard repeatedly recently, so I'll need to deal with that anyway. The pads and shoes have plenty of life, replaced about 3 years ago. Would there be a reason to replace them anyway?

 

Tell your passengers to quit their bitchin' about how fast you brake

 

do you back up your truck often and brake in reverse? the brake shoes have an adjuster that works when you brake in reverse to pick up the slack in the clearance. they can groan or make other noises if they shoes are not in even contact with extra slack in the system. I would try backing and braking first a few times and see if that does it. Its an easy Free test.

 

Old thread from 4 years ago, but 4 mechanics later and none of them have solved the problem.

I'm not sure I understand the above question. It happens whether I inch forward or backward. The noise is under my feet, not at the rear.

In addition to the things in post #4 in this thread, I have since also done:
- wheel bearing repack
- alignment
- brake fluid change
- new shocks
- new tires
- new brake pads
- new brake rotors
- new drive belts
- and other stuff like oil changes unrelated to the axle or wheels

Any more ideas? I'm dropping it off in the morning to another different mechanic.

 

Did you do rear brakes? How about the front calipers? Maybe a bad piston or more? Check master cylinder?