What was found
RNO FLIGHT 2444 LAX-RNO DURING CRUISE NR 1 HYD ISO VALVE & ROLL SPLR INBD HYD CAUTION LIGHTS ILLUMINATED. NR 1 HYD QTY INDICATED APPROX 25%. WE RAN CHECK LIST. NR 1 HYD QUANTITY SLOWLY DECREASED TO OPSI IN APPROX 30 MINUTES. UNEVENTFUL LANDING. STOPPED A/C ON RUNWAY AND SHUT DOWN ENGINES. TOWED TO GATE. REMOVED CHAFED SPOILER HYD. TUBE PN 82920590-003 AND REPLACED WITH NEW. CHANGED ENGINE DRIVEN PUMP. OPS CHECKS GOOD. RETURNED TO SERVICE.