Matching Hydraulics to an Attachment - Hoses, Fittings and Flow Rate

In short: A hydraulic attachment, such as a tilting bucket or a grapple, needs the machine's auxiliary hydraulics to work: a free outlet, sufficient flow, and matching fittings. Before ordering an attachment, check what hydraulics the machine is equipped with, otherwise the equipment may not start at all, or it will work slowly and inefficiently.

Which machines suit a hydraulic attachment

Many excavators, loaders and telehandlers come from the factory with an auxiliary hydraulic outlet meant specifically for attachments, such as tiltrotators, hydraulic buckets or grapples. Some base machines don't have this outlet, and it needs to be installed separately before a hydraulic attachment can work at all.

What to consider when matching hydraulics

• Free outlet: check whether the machine has an unused hydraulic outlet and a valve controlled from the cab to operate it.
• Flow rate and pressure: an attachment needs a certain flow and pressure to work. If the machine's outlet is too weak, the equipment will work slowly or without enough force.
• Fitting type: the quick-connect fittings at the hose ends (hydraulic couplings) must match both in size and type, otherwise a connection can't be made.
• Hose length and routing: the hoses need to reach the attachment without coming under tension or rubbing against the machine as the boom moves.

Common problems

• Wrong fitting: even if the machine has a suitable outlet, that doesn't mean the end fittings match. Sometimes an adapter fitting is needed.
• Insufficient flow: a larger hydraulic attachment (for example, a big tiltrotator or hydraulic grapple) needs more flow than the machine's outlet provides, causing the equipment to work slowly.
• Air in the system: air that gets into the system during connection causes jerky, uneven movement until it's purged out.
• Dirty fittings: dirt on a fitting prevents it from closing properly and allows leaks to develop.

If the machine has no hydraulics

Some older or base-configuration machines don't have an auxiliary hydraulic outlet. In that case it's possible to install one separately, but it's a bigger job, and it's worth considering whether a mechanical attachment (such as a mechanical bucket or fork) wouldn't be a simpler and cheaper solution for your work.

Connection to lift capacity

A hydraulic attachment is usually heavier than a similar mechanical version, since it has cylinders and additional mechanics. That in turn factors into the machine's lift capacity calculation, which we cover in more detail in our article attachment weight and machine lift capacity.

We'll help clarify

Send us the machine's make, model and information about its existing hydraulics, and we'll help determine which attachment is compatible with your machine. Check out our attachment range too. Get in touch via our contact page.