If you are absolutely sure the pump is the problem, a replacement is you best choice. Also, be sure the complete hydraulic system is flushed clean and inspected for contamination. Hopefully your filter would have trapped any debris from the failing pump.
Ensure you don't have another issue causing the noise, cavitation due to clogged filter, low fluid level or air leaking into system on intake side. Air leakage will normally cause an overflow or leak of fluid, so I'm sure you'd mention that if it were the case.
Dan & Loretta, US Army Retired Aero Scout Pilot
2012 Fleetwood Providence 42P Class A/DP
Spartan Chassis, 8.9L Cummins 450HP