Brown Forestry Products Manuals

Brown Forestry Products Customer Support

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:

HKX  800-493-5736

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.

Recommended Grease:

  • 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.