Daily

• Check the ISO-side pump lubricant. If it’s gone cloudy, gel-like, or noticeably darker, drain and refill the reservoir — moisture contamination shortens packing life fast.
• Pull and rinse the inlet strainer screens. Replace a screen once more than about a quarter of the mesh is blocked.
• Look for a light film of resin seepage on the B-side pump rod and wipe it down while the unit is off.

Every 3–4 Weeks

• Change the ISO pump lubricant even if it still looks clean — ordinary seepage past the packings will discolor it on this schedule regardless.

Every 500–1,000 Hours (or 6–12 Months)

• Change the hydraulic fluid and reservoir filter. Go with the shorter interval (500 hrs / 6 mo) if the unit regularly runs above 90°F ambient; otherwise 1,000 hrs / 12 months is fine.
• Use an anti-wear ISO 46 hydraulic oil rated for anti-foaming, oxidation stability, and water separation — don’t mix mineral and synthetic oils in the same fill.

Annually

• Pull both proportioning pumps and inspect the pistons and cylinder bores for scoring. Replace all packings, o-rings, and bushings as a set — this is what the piston/cylinder seal kit above is for.

As Needed

• Belt looks glazed, cracked, or is slipping: replace it (AX46) rather than tensioning around a worn belt.
• Heater running hot or not heating at all: check RTD placement and heater element resistance before assuming the element itself is bad — a mis-seated RTD is a more common culprit.
• Pump won’t reverse direction: it’s almost always a proximity switch that’s drifted out of range of the switching plate, not the directional valve itself — check switch gap before replacing parts.

Full step-by-step procedures are in Graco’s official Reactor 2 Hydraulic Repair-Parts manual (334946) — we’re happy to walk through any of these over the phone.