"Real" brakes for the 425?

[smartguyz]

\"Real\" brakes for the 425?

Hi guys -

Given the discussion on the PT425's lack of 'real' brakes (e.g. ones that actively stop the machine in case of hydraulic failure) does anyone have any practical ideas on how this might be accomplished? How do the emergency brakes on the PT1845 operate?

-Rob /forums/images/graemlins/cool.gif

 

[Bob999]

Re: \"Real\" brakes for the 425?

Short of replacing the wheel motors with motors with integral brakes-most hydraulic motor manufacturers make such motors-- I don't have any ideas for installing service brakes on the 425. This is the approach that PT uses on the 1445 and some other tractors. The literature describes it as wet disc brakes. I believe they are electrically actuated. The demo 1430 that I tried at the factory had this feature installed but so far as I know PT has never sold the 1430 with this feature.

The 1845 has what PT calls the BRAKE TENDER system. There are spring applied disc brakes installed on each wheel. These brakes are connected to an hydraulic circuit that is pressurized by the variable volume pump used for drive power. When the system is pressurized the brakes are released. The system can also be pressurized by a hand pump. So--when hydraulic pressure is present and the selector handle is properly set the brakes release. If hydraulic pressure drops--either a failure or shut down--the brakes "automatically" set.