Engine/Transmission (1998.5 - 2002) Power Steering Help

[DPrew]

I'm trying to work some kinks out of my power steering system. I have no noticable leaks on the gear box, pump, or lines. My gear box and pump are both new AGR units. When you shine a flashlight into the power steering reservoir you can see almost microscopic bubble that seam to permeate the fluid. Not foam, but thousands of very tiny bubbles.



The tiny bubbles can't be seen without a flashlight and you must look really close to notice the bubbles. From a distance the fluid looks normal. I'm wondering if the Hyroboost is the source of the bubbles. There is a small factory installed hole on the bottom of the hydroboost that I noticed was emitting a very small amount of fluid. The fluid made the bottom of the Hydroboost housing slightly wet just around the hole but not dripping.



I also notice that if the truck is stationary and I apply the brakes even a little while turning the wheel it effect the steering a lot. I know the brakes and steering feed off the same vacuum source. If I apply the brakes all the way you can't even turn the wheel. The Hydroboost is taking all the vacuum away from the steering box.



I'd like to hear from someone else the effect applying the brakes have on the steering of their truck while stationary. Your feedback would be very helpful. When I turn the wheel and apply my brakes it totally interferes with the steering.

 

[B.G. Smith]

If you are talking about the 2002 truck in your signature, there is no vacuum connected to the braking/steering system. The steering is power assist from the power steering pump as are the brakes. The hydroboost is a cylinder with a piston inside with high pressure nitrogen on the dead end side and power steering fluid on the other, when the pump is running, it pumps fluid into the cylinder, compressing the nitrogen and then stores it there until there is not enough pressure to activate the brakes or to turn the steering. It is supposed to provide a couple of applications of the brake after the power steering pump is off. Sounds like your hydroboost has lost its nitrogen charge which could also be causing the bubbles if there is still some nitrogen left in it. I think there are aftermarket suppliers for the hydroboost, do a search on here as there should be a lot of info. bg

 

[DPrew]

I guess I meant the hydraulic pressure created by the PS pump when I said vacuum. The high pressure hose on the PS pump has to be vacuum rated hose so it won't collapse. I guess because of the vacuum rated hose I was thinking of it as vacuum. I know there is an actually vacuum pump bolted to the PS pump as well. Thanks for the feedback.

 

[MOtero]

as for the tiny bubbles, it could be your hydroboost as has been said or just a small leak somewhere.



now turning and appying the brakes. I am steering suspension brake tech for a cheby dealer here so i get that concern alot. when turning the wheel the pump is being "loaded" in terms of use. when you apply your brakes its being "loaded". so add both those loads to your p/s pump at the same time and its working real hard to keep the pressure and flow that they both need.



my truck does the same thing when turning and hitting the brakes, all hydroboosts systems work that way. its worse with a 4x4 diesel. not to mention with bigger or maybe under inflated tires.

 

[jkern]

mine has done the same thing for a long time... i have chalked it up to two problems:



1. the nitrogen has leaked off over time because if the truck ain't runnin, got no power brakes.



2. a power steering pump that doesn't supply enough gallons per minute flow to fully power both the steering and the brakes.



my question is this: how did these trucks make it out of the engineering and testing phase with poor track bar designs, marginal brakes, and underrated power steering pump... these are all or could be safety issues!



i guess they really don't test them for "millions of miles" before manufacturing as they claim.