Problem: Stiff power steering on an Isuzu Dmax (How to solve it?)

[Jim]

Good day all, my issue is a stiff power steering on an Isuzu Dmax. Pbly a vehicle yall not too familiar with, but it shares a bit of mechanics with the Rodeo. But it is a power steering issue so, not necessarily vehicle specific.

SORRY it is long, I just want to properly explain what I did.

I purchased the van used, the steering was stiff, and intermittently it will get soft. Then it just remained stiff altogether. Initially, I thought pump, I bought one out of Thailand, no change, I bought a rack out of Thailand and it worked. It was easy for about 3 weeks and then stiffened up to the point I needed two hands to take a corner. One day the rack sprung a leak on top by the pinion, rebuilt the rack, again, worked well a week or two, then stiffened up. Then the pump started leaking, I swapped with the original and the steering would be stiff until I rev, again pointing to the pump.

I eventually got an OEM rack and pump. Steering was again soft, I flushed the system, bled for about half-hour, dropped the van, and steering was soft. Went on a drive and on literally the third corner the steering locked up, I had to rev to get it to turn. I took it home, jacked it up to bleed again, but you could have felt the difference. It was slightly softer cause the wheels were off the ground, but you could feel the lack of assist compared to the first time I jacked the vehicle up. I replaced the high-pressure line as well

I gave up and took it to a shop who are now sounding as clueless as me!! Suggesting cradle bushings which are good! And the lift kit and tire size which is bs, i am running a 2inch lift with 31inch tires, guys are running 3inch lift with 33inch tires off-road with no pblm. This is not heavy steering or slight stiffness from some component binding, this is a constant failure of the steering system.

Any insight will be greatly appreciated!!!

[Miky]

I am inclined to concur with Jesse on this one it is possible that the rebuilt pump does not have large enough veins in it to circulate enough fluid quick enough to support the demand after thinking it through and based on what you have said especially having to rev it up to get the proper assist needed I would bet the resivor and or the veins on the pump are not large enough to accommodate the demand