Is there any better replacement Power Steering Pumps than stock?

[Blacksdieselhp]

I currently own a 2003 and two 2005 Dodges and all three are hard to turn when sitting still. Is there an aftermarket pump out that performs better or should I just replace them with new stock units? Or do you guys have a different fix?

 

[Luken]

http://www.pscmotorsports.com/index.php?cPath=98&osCsid=db94c3a90f8eb1e76310d0805fac0138

 

[Blacksdieselhp]

Thanks man, but I only saw one for up to 2001 on there.

 

[rjohnson916]

I would like to know too, I've noticed mine is very hard to turn sitting still also. Maybe it's me but seems like I always hear the pump hissing at me every time the steering wheel moves.



-Ryan

 

[sag2]

I doubt you can find a pump large enough that will still mount easily on the engine because of the physical size. The hydroboost system used on Ford, Chevy and Dodge all act the same way when sitting still with the brakes applied. The situation is much worse on trucks with larger tires and especially higher offset wheels.

The problem if you want to call it a problem is the hydroboost system is designed for safety with the brakes being primary, and the steering being secondary. If you put the flow tester on our diesel pump it will flow a maximum of 3. 3 GPM with no brake or steering input. Add brake input and the flow and pressure drop dramatically. Since this situation is only when stopped, it is hard to argue it is a safety problem from a steering standpoint.

Now for why it occurs you need to look at steering geometry. In order to make the trucks handle safely you need to have the tire contact patch something other that a fixed point directly below the center line of the knuckle. In the real world, as you turn the tire from left to right, the contact patch moves forward and backward in relation to the true center line of the knuckle. So in a sense, the wheelbase (as measured from contact patch with the ground from front to rear tires) changes as the steering wheel is moved from lock to lock. Now if you are stopped with your foot on the brake, the front tires are having to drag themselves forward and backward as the steering wheel turns lock to lock. The extra weight on the front end from the engine does not help things. You will find if you take your foot off the brake and allow the truck to move slightly forward and backward as the steering it turned, the situation does not occur. This is because the front wheels are no longer dragging, they are rolling.

As a side note, the more caster you have, the worse the problem is, and our trucks love caster to drive straight. So unless you remove weight from the front end (get rid of the mighty Cummins), or find a much larger pump and a heavier steering gear you are not going to change much. So the best you can do is use brakes lightly when turning the wheel stopped to minimize pressure/flow loss to the brake side of the hydroboost, or let the truck roll slightly (as little as an inch) when turning the wheel and it is much reduced or eliminated.

Now before you flame me for not demanding the big three step up and just upgrade the entire package, think about how expensive our trucks are now, and how much more expensive they would be for every buyer for something that only a few owners will experience. We live in the real world, and there are trade offs that we must make in all areas of our lives.

 

[JHardwick]

^^Very good explanation.

 

[Bodie]

AGR makes some good pumps, I have one on my 2000 model. Not sure if they offer any for the newer models.



4wheelparts ... . AGR steering