I have heard replacement hydraulic fans can be hard to find and expensive. Anyway, the hoses should be as follows, 1 pressure hose from pump to fan, 1 pressure hose from fan to steering gear. Then gear output should go up to a small cooler in front of the radiator/ac condenser which then has a hose that returns to the reservoir. There is also a return line from the fan back to the reservoir. So, he would have had to cap off the extra return port at the res. and should have gotten the 99 style pressure hose that goes straight from the pump to the steering gear. My guess is he reused one of the old pressure lines and has it kinked or routed funny somehow. The hose itself should be less than $100 at any parts store, just tell them you have a 99, or look at the info for a 99 online at rock auto or napa or whatever is nearby. Also, make sure its full and has the right kind of fluid.
My Jeep: 2001 Grand Cherokee Limited, 245/65R17 Falken Rocky Mountain ATS, K&N drop in air filter, Bilstein HD's. De-badged, eagle-eye LED Tails & LED 3rd brake light, Addco front and rear sway bars, Superchips tuned & TM snip, interior 6k LED's, Gen3 ccfl projectors with Volt 6k HID lows, akebono brake upgrade with R1 Concepts premium rotors.