Attachments for a CAT 259D3

CAT 259D3 — 20.0 GPM standard, 30.0 GPM high flow, 3,335 psi. GPM means gallons per minute — how much hydraulic oil (the fluid that powers attachments) the machine sends out. PSI means pounds per square inch — how hard that oil pushes. These numbers come straight from Caterpillar's own spec sheet: 76 litres per minute standard, 112 litres per minute high flow, both at 23,000 kPa.

Runs on standard flow (20.0 GPM)

• Pallet forks, rock bucket, and snow pusher — no hydraulics needed. They bolt straight on.
• Root grapple, needs 12–25 GPM — yes.
• Auger drive, needs 10–25 GPM — yes. No case drain needed — it runs a gear motor, not a piston motor.
• Backhoe, needs 10–25 GPM — yes.
• Concrete mixer, needs 10–25 GPM — yes.
• Snow plough, needs 10–25 GPM — yes.
• Trencher, needs 16–30 GPM — yes. Needs a case drain too.
• Brush cutter, needs 17–30 GPM — yes.
• Stump grinder, needs 18–35 GPM — yes. Needs a case drain too.

On high flow (30.0 GPM)

• Forestry mulcher, needs 30–45 GPM — yes, right at the minimum. It will run. It won't have anything held in reserve.

Watch for too much flow

• Don't run the trencher on high flow. It tops out at 30 GPM — exactly where your high flow sits. Standard flow (20 GPM) is the safer choice for daily use.
• Same for the brush cutter (tops out at 30) and the root grapple (tops out at 25). Run those on standard flow and they'll last longer.

How much weight it can lift — and why this machine needs a careful look

Lift capacity, or ROC (rated operating capacity), is the safe weight limit the manufacturer sets. Go past it and the machine gets unstable.

The CAT 259D3 has an ROC of 2,010 lb, taken from Caterpillar's own spec sheet. Our rock bucket needs a machine rated at 2,000 lb ROC or higher.

That's a 10-pound margin. Of every machine we've checked, this is the tightest clearance we've found on the rock bucket. It still passes. But if your machine has counterweight removed, a worn undercarriage, or anything non-stock changing its balance, that 10 lb of headroom can disappear. Send us your exact configuration before you order the rock bucket for this machine.

How attachments mount

The 259D3 uses the Universal Skid Steer quick-attach plate. Caterpillar calls its own version a quick coupler — a mechanical, lever-operated version comes standard, with a hydraulic push-button version available as an option. Either way, it's built to the same universal bracket used across almost every full-size brand. This is a full-size machine, not a mini, so this is the plate you'll be ordering attachments for.

Send us the model and we will check it properly

• Free, whether you buy from us or not.
• Six checks: mount, flow, too much flow, case drain, lift capacity, working dimension.
• support@rightfitattachments.com — replies in less than 24 hours.