All units are built with 100% new O-rings and premium-grade Viton® seals to prevent leaks. Viton® does not break down at high temperatures like conventional seal material. Every pump is computer tested to measure pressure, bypass, fluid flow, valve operation, steering effort and noise for guaranteed performance. All critical components (campacs, spool valves, etc.) are triple-tested to ensure product reliability. Units are supplied with 100% tested and calibrated pressure relief valves for guaranteed performance. Shafts are surfaced to precise specifications to eliminate premature seal wear and extend pump life.