Gauges & Meters

A gauge is the cheapest diagnostic tool in the workshop and the one most machines are missing. Without one you are guessing at pump condition, jet wear and vacuum loss — and you cannot prove a repair worked.

Two numbers tell you most of what you need. Solution pressure at the manifold says whether the pump and regulator are doing their job. Vacuum in inches of mercury says whether the recovery side is sealed.

The range covers pressure gauges in 2.5 inch 0–1500 psi, 0–2500 psi and 0–3000 psi, a 600 psi gauge for Olympus and Razorback, and a 1000 psi water pressure gauge; vacuum gauges in 2.5 inch 1–30 inHg and a 2 1/16 inch 10–30 inHg; and a chemical flow meter with knob.

How to choose

Size the range to the machine, not above it. A 3000 psi gauge on a 500 psi portable spends its life in the bottom sixth of the dial, where it is least accurate. Choose a range where normal operating pressure sits near the middle.

Vacuum is read in inches of mercury, and it is a sealing test. A drop in inHg with the tool blocked points to a leak — a cuff, a lid seal, a tank gasket — long before it points to a tired motor.

Fit the gauge where you can see it working. A gauge behind a panel gets read once a year. One in the operator's line of sight gets read every job, which is where the value is.

Falling pressure over months is the regulator. A pump does not usually fade gradually. A slow decline across a season is almost always the unloader or regulator, and the gauge is how you catch it before the jets suffer.

Pumps are in Pumps & Motors, seal kits in Pump Repair Kits & Seals, vacuum motors in Vacuum Motors, and the wider counter in Parts & Maintenance.