power steering pump

I have a 2001 Tacoma, 4wd and have replaced the power steering pump three times. the pump makes a noise like it has marbles inside. turning the wheel quiets the noise for a while. I have replaced the pump and hoses and flushed the system. The last time I replaced the pump, I used a brand new, Toyota pump. it lasted 4 years before the noise came back.

I disassembled the pump and found no visible problems with the vane pump. I did notice that the casing is completely rusted and the paint has burned off. I suspect that the problem may be in the steering gear where the fluid is not recirculating properly and the pump overheats. Has anyone experienced a similar issue?

 

I think someone mentioned the fine mesh in the fluid tank - I guess you replaced just pump not the tank itself. That mesh can clog up and pump will start making noise by creating vacuum. It's possible the pump overheats too when dunning semi-dry.

 

Damage to the steering rack can put stress on the pump too. Any chance of that?

 

Just thinking any of that (fluid starvation or blockage) would make the pump sound like beaten cat. Like the loud noise the pump makes when you turn wheels all the way to stop.

 

no visible damage to the rack but since this is a recurring issue, I need to inspect the hydraulic ports and bypass for blockage. How difficult is it to drop the rack?

 

Not that difficult. There are write ups for rack bushing replacement. That loosens the rack, then it's just disconnecting the lines and the steering input