Braking noise I can't figure out

[dmw319]

Anyone heard this before? It only happens when I break.. and is intermittent. Brakes are working fine but I can feel it pulsing through the brake pedal...

Another thing (or possibly just coincidence), it seems to happen when it is raining. It was raining in this vid, and it was raining this morning on my way to work when it was also raining...

https://youtu.be/OyWZDKhZLhk

[rpmerf]

Is this the 70 C10 in your signature? What braking setup does it have? Drum / Drum? Disc / Drum?

[dmw319]

Yes, 70 C-10. When I bought it, it had drum brakes all around. I upgraded it to front disc about 6 years ago using ECE conversion parts. Have had 0 issues till a few months ago. But the front is disc and the rear is drum.

[OldBlue70C10]

I would say your front rotors are warped, but its hard to say without actually seeing it in person.

[truckster]

I would say it's warped rotor(s). When it rains, the water makes it more obvious because it acts as a lubricant between the pad and rotor.

[AussieinNC]

Couple of things come to mind....

Disk surfaces need to be machined to return surfaces to a constant parallel measurement, make sure the final thickness is not below minimum use thickness

Those rear drums could also need to be machined to return the inner surface to a round condition...pull the rear drums and look for oil contamination which will give similar conditions

Finally, make sure the parking brake is not partially on, or the cables are not seized up

Keep us up to date with progress

[dmw319]

thanks all!

all good things to think about. its dry today and the sound went away completely

[geezer#99]

Sounds like rear shoes that grab only when wet.

[dmw319]

Originally Posted by geezer#99

Sounds like rear shoes that grab only when wet.

that noise cant be normal. brakes operate fine with no noises when its not wet.


also, the more I think about it (to the above replies).. I have driven in plenty of cars with warped rotors before and this just does not sound the same. its not a pulsing, it is a mechanical clicking/ticking noise that sounds/feels much more harsh than warped rotors do.

still at a loss...

[dmw319]

update: noise is coming from the rear passenger side when I brake:

(someone was in the cab braking when I took the vid)

https://youtu.be/PqN2keD3rkc

looks like I need to take apart the rear drums to see what it could be

[Keith Seymore]

I can't watch the video but here's a thought:

When we did the M van program we had a rear brake problem where the drums were not machined correctly.

The process used to cut the inside of the drum resulted in a "screw thread", which allowed the friction material to grab.

The "screw thread" pulls the shoes away from the backing plate until the show retaining spring force overcomes it, at which point the shoes slam back into the backing plate resulting in a clicking sound that slows in frequency coincident with the vehicle speed.

It only happens on one side, because on the other side the "screw" effect is pushing the shoes into the backing plate, rather than pulling them away.

K

[K5er4Life]

That has to be an easy one. Especially after the most recent video. Pull that rear passenger wheel and see what you’re dealing with. Could be a number of things, broken spring, piece of brake material that came loose, etc. if it had been a while since the last brake job I would plan on just getting all the parts needed to do both sides (wheel cylinders, springs, etc) and do a brake job on the rear.

It doesn’t sound like it’s coming from the pumpkin so I wouldn’t suspect a Broken carrier or bearing. I guess it could be but you’ll know as soon as you pop open that drum.

[weq92f]

.
I wanna see what's behind that drum. Funny how the timing of the sound in my viewer sure made it seem like that wheel weight was whacking something

-klb

[dmw319]

thanks yall.. ill take the wheel off tonight and see what im dealing with

[dmw319]

Update: Took it by a shop and had both rear drums rebuilt with new shoes/hardware/etc. Also had the wheel cylinders replaced. They said it was a mess back there... but the sound is gone and truck brakes much better now.

[Willys_MB]

Bummer, I wish I had seen this a while back, but I was on vacation when you posted. I had a similar issue and the plunger from my wheel cylinder had popped out and was clunking around in there. It was a total mess. I was lucky I made it home when I bought my truck. My first project was getting the brakes brought up to snuff.