748gIII slow hard steering

[rmllarue91]

It's the mid serial number range 590000+
It uses the high pressure priority valve with load sense line from steering valve to priority valve.
It's steers will build 2800ish psi spec in full lock turn either direction.
Main pump standby is the same pressure.
When making normal turn it turns a little around 1000ish psi feels good then wheel gets stiff and pressure drops to 500ish psi. Turn little bit and pressure comes back up and it turns easy for a sec the gets hard again.
If I use grapple at same time grapple functions will slow then stop and steering stays same making me think priority valve it working. Don't believe it's in cylinders because I think wheel would get soft if they where bypassing. Customer put new steering valve and priority valve in trying to fix said issue.
Im taking my flow meter to flow main pump and -4 oring face seal tee to monitor load sense. But try to get a good diagnostic plan for when I go back it's not a major issue it's more annoying if you turn wheel hard it will turn thanks hef for ideas

 

[mg2361]

Do the hydraulics ever slow down on their own or is it just the steering? If the hydraulics slow down then see picture below.

 

[rmllarue91]

Hydraulics seem to function better than steering.
I flowed pump at wide open throttle 25 gpm at 2000psi
New pump spec is 42 gpm
Used is 33 gpm
So it's getting a new pump and I'll report back

 

[rmllarue91]

New pump fixed it. Stand by pressure was a little higher both in spec but the pressure didn't drop off under load much at all with new pump. Blade and grapple much faster.