The fluid families in a nutshell
HL: mineral oil with oxidation and corrosion protection. HLP: HL plus anti-wear additives, the de-facto standard for power packs. HV (or HVLP): like HLP but with viscosity more stable across temperature, for outdoor use and extreme climates. Biodegradable fluids exist for sensitive environments and food-grade fluids for the food industry: use them only when the application demands it, as they cost more.
The right viscosity for your climate and cycle
ISO VG viscosity is the oil’s thickness at 40 °C: the higher, the "thicker". Oil too viscous when cold strains motor and pump at start-up (critical on snow plows and winter liftgates, so VG 32 or an HV fluid); oil too thin when hot increases internal leakage and cuts performance (hot climates and long cycles, so VG 46). If in doubt about the actual cycle, ask us: the answer belongs on your unit’s datasheet.
| Fluid | What it is | When to use it |
|---|---|---|
| HLP, ISO VG 32 | mineral with anti-wear additives, thinner | cold climates, DC units with frequent starts |
| HLP, ISO VG 46 | mineral with anti-wear additives, thicker | hot climates and prolonged duty |
| HV (HVLP) | viscosity stable across temperature | outdoors and widely varying temperatures |
| Engine oil | detergent additives that emulsify water | never |
When should you change the oil and how do you keep it clean?
In compact power packs oil is not consumed: it gets dirty and ages. Practical rules: first change after system run-in, then at regular intervals according to usage intensity, and immediately if it turns cloudy (water), dark or smells burnt. Real cleanliness, though, is won earlier: an efficient breather, top-ups with filtered oil and a sealed reservoir. Contamination is the number one cause of hydraulic component failure.
The mistakes to avoid
No engine oil: its detergent additives hold water in emulsion and foam up in a hydraulic circuit. No mixing different fluids: additive packages can react with each other. No "whatever was in the workshop" for top-ups: one wrong top-up can compromise the whole charge. And if the unit sits idle for months, a periodic unloaded run keeps pump and seals lubricated.