grinding brakes/soft pedal

[sqhurt]

Have 93 xlt 4x4. Has 4 wheel Abs with drums in rear. Last week I put on new shocks,drums,shoes,hardware,rotors,bearings.

Problem I'm having with grinding is from about 5 mph to 15 you can hear like a grinding noise. Not so much metal to metal but like pads on rotors. But as soon as you touch the brakes the noise stops. Oh and there is a new caliper on the driver side and new brake hose on the passanger side.

I jacked car up in front and turned wheels. You can hear the noise as pads are touching the rotors. Also shacking tire up and down and side to side has no extra movement.

As far as the brake pedal itself. I bleed the brakes 3x twice with truck off and someone pumping, and once with truck running and someone pumping. I noticed with truck off you can push the pedal about 3 times and hear like air escaping while pressed but after 3rd time you have a great pedal. Now on the other hand while the truck is running you can pump them and still seem to hear like whush sound from the driver seat. And as well under the hood while pedal is pressed in. On side not the float inside the master cylinder wouldn't come up by itself, so had to use a pick to bring it up.

While doing the whole brake job the master cylinder to go empty. I've tried searching on how to bleed abs system or the hcu and reading all kinds of stuff and seems to be different. Any and all help is greatly appreciated Thanks

 

[rustbucketMI]

If when you are bleeding your brakes the master cylinder goes empty you may as well just start over. That seems to be your first problem. As far as the grinding noise I'd be willing to bet that it is because everything is new and hasn't had time to self adjust,, and break in. In the rear you should have backed off the adjustment nut, when taking off the drums. Back up a few times and those should self adjust. As for the front, which I suspect is where you're hearing the grinding, because you have new pads and rotors everything is still very tight. Drive it a few miles 10+ and see if it makes the same sound. If the truck is on stands and you can turn the wheels by hand then you probably don't have an issue, just noise for now.

 

[sqhurt]

If when you are bleeding your brakes the master cylinder goes empty you may as well just start over. That seems to be your first problem. As far as the grinding noise I'd be willing to bet that it is because everything is new and hasn't had time to self adjust,, and break in. In the rear you should have backed off the adjustment nut, when taking off the drums. Back up a few times and those should self adjust. As for the front, which I suspect is where you're hearing the grinding, because you have new pads and rotors everything is still very tight. Drive it a few miles 10+ and see if it makes the same sound. If the truck is on stands and you can turn the wheels by hand then you probably don't have an issue, just noise for now.

You saying I should go ahead and bleed the master cylinder? If so could i just unhook the lines and leave it in the truck to do so? Thanks

 

[rustbucketMI]

no no no. When you are bleeding your brakes if the master cylinder (really the resivour above it) goes empty then you are going to suck in more air to your lines. This bowl had to always have fluid in it. Which is why I said you may as well start over. My typical method is do 3-4 cycles (pedal to the floor with valve open) and then check this bowl. Generally I fill it up to the very top when I am bleeding.

 

[sqhurt]

The grinding has stopped as of now. Now Im experiencing a good sounding thud/clank. This happens usually about within the first 5 mins of driving it and when brake is depressed. The sound seems to come from the driver side. Yesterday I replaced the brake caliper, and did driver when everything else was done. Also one other thing i noticed when filling master cylinder up that the lil plunger is down even when full. If you take something and give it little help it'll come back up though. Do you guys think I need new caliper on driver side? And would air in the master cylinder cause the plunger to not want to come up?

 

[Roadrunner777]

Did you find and install the little clip on the end of the brake pads?

 

[sqhurt]

Did you find and install the little clip on the end of the brake pads?

I had to purchase the new pins and clips, but yes they are on it.

 

[fastcharlie]

i feel like this doesnt have anything to do with your brakes. you say its gotten worse. you've basically described my cars problem right now, and it needs a wheel bearing. just a thought.

 

[Tony H]

The grinding has stopped as of now. Now Im experiencing a good sounding thud/clank. This happens usually about within the first 5 mins of driving it and when brake is depressed. The sound seems to come from the driver side. Yesterday I replaced the brake caliper, and did driver when everything else was done. Also one other thing i noticed when filling master cylinder up that the lil plunger is down even when full. If you take something and give it little help it'll come back up though. Do you guys think I need new caliper on driver side? And would air in the master cylinder cause the plunger to not want to come up?

Check your spindle nut again. Hopefully it didn't back off.