Frequently Asked Questions
Open vs Closed Loop?
Open-loop is usually the term used when talking about running an attachment off your machine’s own hydraulics aka “Self Powered”. You use your existing excavator’s hydraulic pumps, tapping into them using an existing third valve or priority kit (see: Priority Kits below). To find out if you already have a built-in third valve (priority valve or dual pump valve kit) talk to your dealer.
If you do not have an existing third valve, one can easily be added by going through your dealer.
Priority Valve Kits
Two companies that we personally use and suggest are:
Hydraulic Circuit Technologies 888-603-0080
These two companies specifically make priority valves and are very familiar with our product. When calling them, just let them know you wish to run a Brown Brontosaurus mower head, the GPM of the mower head required, and the make and model of your carrier. The valve needed is just a “single function”, only needs to spin in one direction. They will do the rest and set up your machine the best way possible to run our mowers.
Case Drain Line
The hydraulic motors used on mower/forestry mulchers are hydrostatic motors. This means (to you and me) that they are self-lubricating. These motors take a little bit off of the flow to keep themselves lubricated. The hydraulic return line pressure is too high for your case drain to simply be tied into it, so a third line, call the case drain line is required. This line simply goes back to your hydraulic tank.
Gear Motor vs Hydrostatic Motor
Gear motors only require two hydraulic lines: A flow and return line. These are used on small and mini excavators where the pressure is 3000 max psi or lower. Over 3500 psi a case drain will be required and a hydrostatic motor will be used instead.
How much Horse Power is required?
The formula for calculating horsepower is as follows:
HP = GPM * PSI * .000583
The rule of thumb is 1 HP to pump 1 GPM at 1500 psi
Schematics and Breakdown Diagrams
Hydraulic Motor Schematic
Hydraulic Pump Schematic
Pin Specification Sheet
Have us build you a forestry mower or stump grinder? We always need to double-check your pin dimensions with what we have on file. Be sure to fill out the pin specification sheet with your pin and stick dimensions. You can download the sheet below and email or fax it back to us.
Excavator Pin Data Sheet
Bearings and Grease
We recommend adding grease to your bearings daily utilizing one hand pump of grease per hour of mower head usage. After an 8 hour day of running your mower, add 8 pumps of grease into each bearing.
- Amalie – Blue High Temp – Lithium Complex #2
- Texas Refinery Corp – Paragon 3000
Types of Bearings: We carry Rexnord, Timken, and SKF Bearings in stock in our 2 15/16 size. Timken and SKF in the 3 11/16 size.