Buy the wrong attachment for your machine's hydraulics and you either get an underpowered tool, an overheated system, or both. Here's the practical breakdown — attachment by attachment — so you don't find out the hard way.
The math isn't complicated. A standard-flow skid steer running 17 GPM at 3,500 PSI produces roughly 34 HP of hydraulic power. A high-flow machine at 40 GPM and the same pressure produces over 80 HP. Double the flow, more than double the usable power at the attachment. That gap is why some tools simply don't function properly on standard-flow machines — not sluggishly, not partially, but actually don't work at designed spec.
Most Canadian operators run one of a handful of machines: Bobcat S/T/R series, Case SV series, Cat 226D/232D/262D, Kubota SSV65/75, or John Deere 317G/320G. Every one of those has both standard-flow and high-flow variants. Knowing which you have — before you buy an attachment — is step one.
Check the serial number plate on your machine, then look up the spec sheet on the manufacturer's site. What you want is the auxiliary hydraulic flow rating, listed in GPM (gallons per minute) or L/min. Standard-flow machines fall in the 17–25 GPM range. High-flow machines run 30–45 GPM.
Some machines have high flow as a factory option — you need to know whether your specific unit was ordered with it. A Bobcat T650, for example, offers both standard (23.6 GPM) and high-flow (36.4 GPM) configurations. Two visually identical T650s at a rental yard can have completely different hydraulic capability. Ask the dealer, pull the spec sheet, or check the cab — most machines with high flow have a dedicated high-flow circuit switch or selector.
These are tools with lower hydraulic demands — either they move slowly by design, or they use hydraulic power intermittently rather than continuously.
These tools have hydraulic motors that genuinely need the volume a high-flow system provides. Running them on standard flow means the motor spins slower than designed — less cutting speed, less production, more heat, and faster wear.
Some attachments work on standard flow but perform noticeably better — or have specific models rated — for high flow. This middle ground trips up a lot of buyers.
| Attachment | Standard Flow (17–25 GPM) | High Flow (30–45 GPM) |
|---|---|---|
| Brush cutters (light to medium) | Works For saplings, grass, light brush | Better Dense brush, faster rotor, more throughput |
| Snowblower (60–72") | Marginal Wet heavy snow struggles | Required For production clearing in Canadian winters |
| Stump grinder | Works Small to medium stumps, slow pace | Better Large stumps, production grinding |
| Auger (heavy-duty) | OK Smaller bits in soft ground | Better Large diameter bits (18"+), hardpan, caliche |
| Trencher (chain) | Works Normal soil utility trenching | Better Rocky or frozen ground |
| Hydraulic breaker | Works Most breakers rated for standard flow | Check spec Some large breakers need higher flow |
There are two failure modes. The first is buying a high-flow-required attachment for a standard-flow machine. You'll either damage the attachment motor (they run hot when starved for flow), void the warranty, or just get 40–50% of rated production. The attachment dealer will tell you this before you buy — if you tell them your machine's GPM rating. Don't skip that step.
The second mistake is adding a high-flow kit to a machine that wasn't designed for it. High-flow hydraulics aren't just a bigger pump — they require larger reservoir capacity, upgraded coolers, and bigger lines throughout the system. Aftermarket "high-flow conversions" exist, but they vary wildly in quality. A proper conversion through the OEM or a qualified hydraulic shop costs $3,000–$8,000 CAD and is worth doing right. A cheap conversion that bypasses the cooling circuit will toast your hydraulic system on a hot July afternoon running a mulcher in Northern BC.
| Machine | Standard Flow (GPM) | High Flow Option (GPM) |
|---|---|---|
| Bobcat S650 | 23.6 | 36.4 |
| Bobcat T650 | 23.6 | 36.4 |
| Cat 262D3 | 25.6 | 40.1 |
| Cat 299D3 | 29.0 | 45.5 |
| Case SV280 | 22 | 35 |
| Kubota SSV75 | 22.5 | Not offered |
| John Deere 332G | 25.2 | 38.7 |
| New Holland L234 | 24.7 | 35.3 |
Note the Kubota SSV75 — no high-flow option. A common machine on Canadian acreages and small operations, and it means forestry mulchers, large cold planers, and production snowblowers simply aren't compatible. Not a knock on the machine — it's great for what it does — but knowing the limit before you buy an attachment matters.
Pull your machine's spec sheet. Find the auxiliary hydraulic flow in GPM. Then check every attachment you're considering against its required GPM range. Takes five minutes. Skipping this step has cost Canadian operators thousands of dollars in returned attachments, voided warranties, and damaged hydraulic systems.
For most landscapers and property owners running standard buckets, augers, tillers, and forks — standard flow is perfectly adequate. The high-flow conversation only matters when you're adding rotary tools: mulchers, cold planers, rock saws, heavy brush cutters. Plan your attachment lineup before you spec your next machine, not after.
Looking for specific models available in Canada? Browse the skid steer attachment catalog for verified product pages on real models sold through Canadian dealers. Whether you need standard-flow or high-flow attachments, we have categories for buckets, augers, brooms, and rotary cutters.