I get an occasional strange noise. It kinda sound's like a pump, or hollow tin can sound. If I step on the brake pedal, it goes away. The power steering fluid was low, but topping it off did not make the noise go away. I also sometimes get a wet brake feeling,,,meaning they don't work so good. Feel's like they are wet. Pumping the pedal does not help. I did bleed the brake's and that didn't help either.

Could this be my vacum pump. I thought I read there was an electric vacum pump on a 04. Where would it be located. Any way to test it . Thank's.

 

my 04.5 doesnt have a vacuum pump, but mine is a manual. your brakes however, use hydroboost, hydraulic power from the power steering pump to provide assist for the brakes.

 

This thread shows a photo of the vacuum pump. Apparently in 3rd gens it's only on trucks with automatics, to operate the cruise control.

https://www.dieseltruckresource.com/...d.php?t=124486

If your fluid was low, I wonder if you have a leak somewhere. Otherwise, I wonder if there is some air in the system that hasn't worked it's way out...

 

Well I believe it's the power steering pump. The noise is getting louder and louder. It now make's it when I turn the steering wheel. Look's like it might be new pump time.

I wonder if I could put some pump treatment in there. Can you use that stuff with hydro-boost.

 

Of course, you've checked your HydroBoost resevoir for enough ATF+4... ?

 

If that is one in the same as the power steering pump resevoir,,,,then I'm good. Like I said before, it was low. If there's another resevoir,,I missed it. They're the same thing , aren't they?

 

yes they are the same reservoir