Hydro boost making a fairly loud humming noise?

[The motor guy]

I didn't notice this until yesterday when the temps got a little cooler, then it went away once things warmed up. Now today it was even cooler, so it was worse. Both the brakes and the steering make the noise.

 

[The motor guy]

Makes me wonder if the power steering fluid is low? This is my 99 dodge ram cummins 5.9

 

[redhat]

I would check fluid level first. On GM hydroboosts, low reservoir level will make noise turning wheel and braking.

 

[The motor guy]

I would check fluid level first. On GM hydroboosts, low reservoir level will make noise turning wheel and braking.

Okay. That's my thinking is, cooler temps caused the level to go down. Kind of a coincidence though.

 

[The motor guy]

Added fluid. Nothing was on the stick. She's quiet now.

 

[redhat]

Added fluid. Nothing was on the stick. She's quiet now.

Awesome glad to hear. If you don’t see fluid anywhere leaking then might have just been low.

 

[The motor guy]

Awesome glad to hear. If you don’t see fluid anywhere leaking then might have just been low.

It's the one fluid I didn't check when I bought the truck. I think it has a small leak, but nothing major. Power steering fluid doesn't just disappear lol

 

[MattPersman]

Could be a hydro boost leak internal or external look at the rod coming through the inside by the pedal

I like to change the fluid in them every 30k they seem to wear the fluid out faster than other applications

 

[thastinger]

Added fluid. Nothing was on the stick. She's quiet now.

I can only imagine the racket that thing was making if you could hear it over a cold start 12Valve

 

[The motor guy]

I can only imagine the racket that thing was making if you could hear it over a cold start 12Valve

It wasn't your typically Power steering pump whine. Just sounded like aerated fluid