The Diesel Stop banner

1 - 9 of 9 Posts

·
Registered
Joined
·
115 Posts
Discussion Starter #1
Having trouble diagnosing a noise that occurs during medium effort braking. The noise is absent during light and heavy braking and is always present during moderate braking. It started about 3,000 miles ago and has gotten a little more noticeable recently. It's not a metal to metal sound. It sounds like a mud tire rumble or like I'm on a rumble strip. Tires are Micheline LTX M/S with 30,000 miles and have a lot of tread remaining. This is the second set that I've had and the first never made any noise for the life of the set. I've checked the brake pads and rotors twice. Pads are original, measure over .150" thick and look good as do the rotors. Front wheel bearings were cleaned and packed about 10,000 miles ago and still feel fine. Cannot detect any issues with swing bearing or U-joints. Differential lube is full and has 10,000 miles on it since it was changed. The noise only occurs during braking. I am about ready to service the brakes just to see if that cures the issue. I figure after 119,000 miles on the original pads, it can't hurt. Any ideas?
 

·
Registered
Joined
·
3,500 Posts
Sounds like pads or an issue caused by stuck slide pins.

Have you checked the inside pads as well?

119k is a good pull for pads - and definitely check the slide pins.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #3
Looking back at notes on my service log, the noise appeared about 5,000 miles ago. All brake pads inner and outer have minimum of .180" remaining. The truck has never seen heavy usage. I've towed light loads (under 4,000 lbs) for less than 30,000 miles. Rarely use heavy braking, usually coast up to stop signs and traffic lights. No off road use. Pins have been checked several times over the life of the truck, once since the noise started. Each time they pass inspection, no sticking, rust, corrosion, etc. observed. Rotors look good but I haven't measured runout. I'll be taking a deeper look into it as it's gradually getting worse. Thanks for the reply.
 

·
Registered
Joined
·
33 Posts
If I have 3/16 of an inch of pad left I'm ordering pads and rotors. It reminds me of rear brakes needing to be replaced. You'll feel a rumble in your backside instead of through the pedal. Not sure if it would be slide pins or warped rotors. I replace both when I replace the pads. It is not worth the trouble trying to reuse the pins, rubber boots, or having the rotors turned.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #5
Followup

I replaced the brake pads and the noise went away. Went with Hawk LTS pads. I did not find any obvious cause for the noise. Caliper slide pins are in good condition. I cleaned and lubricated them, replaced the boots and caliper hardware. Turned the front rotors for light grooves. Probably didn't need it but...
I guess the noise will remain a mystery.
 

·
Registered
Joined
·
5,706 Posts
Didn't see this originally, but as you now know it's the pads. At that thickness you were due for a pad change. Most of OE brake pads today use an underlayer for many reasons; bonding, noise reduction, thermal barrier, etc. Usually when this material starts to become the rubbing surface of the pads rather then friction material you can get all types of NVH.

>>>Turned the front rotors for light grooves.<<

We'll see you back in about 10k-15k miles for pulsation if it was with a bench lathe unless those LTS pads save the day.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #7 (Edited)
The rotors had .002" runout before the work. Now have .005". It was done on a bench lathe. Maybe the LTS pads will save me. I'll check back with the results.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #9
>>>Turned the front rotors for light grooves.<<

We'll see you back in about 10k-15k miles for pulsation if it was with a bench lathe unless those LTS pads save the day.
The Hawk pads must have saved the day. !0,000 miles and no pulsating.
 
1 - 9 of 9 Posts
Top