Ok, so am having this really weird noise on a 2003 4wd SB 2500. Sounds like the ABS pump is activating, but it can be with or without brakes applied. It is hard to describe, sounds like an electronic buzzing. It is basically right under the drivers left foot(noise origination). It started as a weird noise only going over bumps, but the car had to be rolling. I can bounce the car, unless it is moving, no noise.

This weekend pulled a 35' 5th wheel 500 miles, and now it is any time I am on the brakes and actually slowing down(plus the bumps). If I am just dragging the brakes and not really slowing down, no noise. But the second I get on the brakes(with trailer) it is really loud. The noise vibrates slower and slower as my speed decreases. If I am on a highway and I go through a wash, very easy to hear the buzzing. No driveability issues while going down the road, smooth and quite, no weird vibration, really did great on the road trip.

Things that have been checked:
1. Bearing Units(spin fine, no play)
2. Suspension joints, look good no real play.
3. Front axle has good fluid level.

Other Clues:
1. Rebuilt tranny (2k miles ago)
2. 285 AT tires
3. Stock supension
4. 170k miles.

Tried searching, but couldn't find anything. I have had lots of Dodge's and never had this problem. Not sure if I should be worried, or if it is just another quirk.

 

I have seen the power brake booster hoses cause that noise. Fluid going through the hoses will make loud vibration noise. Most likely the high pressure hose to the brake booster is bad. The noise will get louder the harder you step on the brake since max pressure is going to booster then. Feel the hose after driving carefully if you find one spot that is very hot then the hose is collasping internally. Do you feel any vibration in steering wheel?

PARTS REQUIRED:
Qty. Part No. Description
1 52113926AF Power Steering Hose - Pump to
Hydraulic Booster
AR 05013457AA Fluid - ATF +4
REPAIR PROCEDURE:

 

Thanks for the reply.

No vibration in the steering wheel. I would beleive that it is the brake booster, definitely where it sounds like it is coming from, but how come it does it on bumps?

Another clue:
The buzzing on bumps, seems to get quieter as the truck warms up.

 

Well, I have now replaced both hydroboost hoses. From the pump to the unit and from the unit to the gear. Still does it, with really no change.

I was really convinced that would fix it, but still no luck.

When not towing it happens when I slam on the brakes or hit a big bump, but only while rolling. Doesn't matter if I am on the brakes or not. Any kind of front suspension compression makes it buzz

When towing, it is very load anytime I am on the brakes(more pressure than empty), and it still happens on a compression(bump, dip etc. )

I have taken it to one shop, had no idea where to look. It runs great, no brake or steering vibration. If I didn't hear it, there would be absolutely no problem, but it sure does make me nervous.

Thanks in advance for any ideas.

 

Is it coming from the area where the abs controller is? I don't know if yours is in the same place mine is.
On a wet/slick surface, get the abs to activate and see if it is the same noise. If so, maybe it's your controller module.
When it makes the noise does it pull to one side? Any codes? If you can test the abs on a slick surface, try to also test it side to side. In other words, have the right side tires on pavement, and the left side on gravel. Switch sides and repeat. This may help isolate the problem if it is a brake/abs issue. I think if you had a problem in front (abs activating on one wheel) it would pull to one side and you would feel it. If it is the back you may not be able to tell.
I would also do the test in reverse.
Good luck, and let us know.

 

I know this will sound off the wall but.... Is there any chance you've got a short in the starter or the wires going to it. It could be just the starter motor spinning without engaging the solenoid.

 

Mine was doing the same thing, but worse, it would buzz like you're saying and if I applied the brakes S L O W L Y the truck would stop fine, but if I got on the brakes hard at all, the ABS would just kick in on dry pavement and the truck wouldn't stop. Also, no speedo and ck engine and ABS light on.
Don't know what part was making the noise as my problem ended up being an issue with the Bully dog programmer and BD re-configured the programmer with me over the phone, problem solved.
If it was the hydro boost I think you'd feel it in the steering wheel too since the ps pump runs the hydroboost, like I could feel it in the brakes when my steering box went out.

 

Checked the battery cables, they all look fine. It doesn't sound like a fast spinning. It really does sound like the ABS activating. More of a erg,erg,erg,erg but alot faster.

Haven't had a chance to lock up the brakes on gravel, I will try that later today.

I did pull the ABS pump fuse, I got the brake and abs light and the noise is still there. I have never gotten any vibration in the wheel or brakes. It is so weird because there is no check engine light, brake light(with fuse in) and everything is working so good. I can more or less lock the brakes up on pavement, and besides the buzzing, it works great. I have an older edge module with a quadzilla monitor, I guess I could pull that and see if it is causing a problem.

Is there something I am missing that could be inside the firewall? Some sort of electronic gizmo that I am just not seeing that could be causing this?

Thanks for all the reply's

 

I’m having the exact same issue on my 2006 Dodge 2500 Diesel Mega Cab

Oddly enough it developed after replacing the brake master cylinder about 4 months ago & the power steering pump about 2 months ago

started as an occasional noise & has become all the tine when braking or any significant jolt ( without brake pedal even being pressed )

Other interesting occurrence, the 1st power steering pump replaced only lasted a few days and had to be replaced

Hopefully someone has the cure & responds here quickly

 

On the early gen 3 there was a similar issue and the fix was a large dampener weight clamped midway up the booster hose. Not sure how this was done, but seem to remember that there was either a service bulletin or letter put out by Dodge. My truck has this dampener weight and it was installed free of charge by Dodge. Perhaps your truck can have the problem rectified the same way?

 

Could you please send me a photo of what your booster line dampener looks like plus showing where it is located on the booster line

 

The damper is almost hidden, so it was difficult to take a decent picture. Hope these two pictures help in some small way

 

I am relatively new here so excuse my errors. I am having this exact problem and wondering if you found a solution.

 

What is the year and model of your truck?

 

Merry Christmas and tnx for your repky. 2003 2500 cummins 4x4. I am relatively certain it is the top hydraulic line from the pump to the brakes. However it is very tough to get the old line off at the pump.