Caterpillar’s new 4-tonne, Cat 304, and 5-tonne, Cat 305 CR, next-generation mini hydraulic excavators boast higher bucket breakout forces and deeper standard digging depths. The company said these features increase performance by up to 20 percent over the company’s E2 series. The new 304 and 305 include extended grease intervals and filter service life, which combined with common components throughout the line and flat, easy-to-replace side panels, can reduce owner and operating costs by 10 percent.
The new 304 and 305 CR models are the final machines to be reengineered to the Cat next-generation mini hydraulic excavator line concept. From the 1.5- to 10-tonne class models, all 17 to 20 Cat mini hydraulic excavators in the range (depending on region) offer common features and consistent controls layout to simplify training and operator adaptation.
New 304
The 304 comes with a new reduced radius design and a narrow 66.9-in track width for better access to small spaces. The 304’s narrow track is 10 inches slimmer than the 304 E2. Its reduced radius allows for greater stability, both 360-degree and when traveling with loads, while its extra counterweight option takes the model to an even higher level of stability.
New 305 CR
The new engine on the 5-tonne class Cat 305 CR Excavator delivers nearly 9 percent greater power according to the company. Hydraulic system improvements provide higher breakout forces — 49.2 kN (11,061 lbf) bucket, 28.3 kN (6,362 lbf) standard stick and 25.2 kN (5,665 lbf) long stick — to improve digging efficiency in hard rock applications. It also offers 5.6-inch deeper dig depths than the 305 E2. Its compact radius swing reduces overhang when working to the side, while its 78-inch track width and new extra counterweight option help to optimize stability and lift performance in confined spaces.
Additional options
Both excavator models now offer an angle dozer blade option to optimize machine flexibility in backfilling and finish grading applications. In addition to offering ample above- and below-grade travel with standard float function for easy clean-up, the angle blade moves 45 degrees left or right of center. The angle blade movement is controlled by the right-hand joystick, while the left joystick handles machine drive.
Interchangeable counterweight packages offer the balance between low ground pressure and lifting performance. The Cat Stick Steer System allows the operator to switch from conventional lever/foot-pedal steering controls to low-effort joystick operation. The 304 and 305 CR offer two travel speed ranges and standard cruise control.
Both come equipped with the Cat C1.7 Turbo engine. Standard auto idle, auto engine shutdown and efficient load-sensing hydraulics with variable displacement pump help to lower fuel usage. High main-relief pressures, coupled with flow rates, generate the hydraulic capacity for high digging and lifting forces and more efficient use of a range of attachments. Complete with quick-disconnect lines, the standard auxiliary system provides the choice of one-way, two-way or continuous flow.
Comfort features
The sealed and pressurized cab enclosure is available with heating and/or air conditioning for all-weather climate control. The cab’s large glass areas plus skylight offer all-around visibility. The large display with advanced touchscreen option provides intuitive machine function control and easy monitoring of critical operating parameters. A canopy option is available in some regions. Daily maintenance checks for the 304 and 305 CR are quickly made from ground level through side doors.
