Caterpillar's new D Series mini hydraulic excavators — models 303.5D CR, 304D CR, 305D CR (pictured) and 305.5D CR — are engineered to be compact-radius machines that feature enhanced stability for greater productivity, a redesigned work-tool coupler, load-sensing hydraulics, and meet Tier-4 Interim emissions regulations.

Increased-width undercarriages for the 303.5D CR and 304D CR, and heavier counterweights for the 305D CR and 305.5D CR enhance machine stability, allowing increased lift capacity, more effective use of reach and digging forces, increased capability when handling heavy work tools and improved machine balance for operator comfort.

A new pin-grabber-type coupler combines positive work-tool retention with a design that maintains tight tolerances between coupler and tool, significantly reducing wear.

“Our new hydraulic coupler was designed for safety and all the functions can be performed from inside the cab when changing buckets,” says Robert Jackson, market development engineer, Caterpillar. “The required secondary safety lock is built into the coupler and it is not necessary to leave the cab and install any manual safety pins when changing tools.”

A standard-equipment two-mode auxiliary-hydraulic system, complete with lines and quick connectors, can be switched between single-direction and bi-directional operation for effectively using work tools ranging from hydraulic breakers to augers. The implement hydraulic system is a responsive, load-sensing system resulting in low-effort pilot controls for optimum control and fast cycle times.

“The D Series was designed to handle this additional reach and weight, making the machines more versatile,” says Jackson. “The zero-tail-swing 303.5D CR and 304D CR will help rental customers by not having to worry about damaging the back of the machine while it is out on rental.”

Verified by Robert Jackson, market development engineer, Caterpillar Inc.

Reader Service No. 140 • freeproductinfo.net/rer

Vital Stats

Net hp range: 30-47 hp

Long arm digging depth range: 10.33-12.66 feet

Bucket rotation: more than 200 degrees