Looking for some info on a marooka MST-700...she moves forward ok, wont turn to the right, and barely turns to the left and it's all she got to move backwards, I found a new drive hose had been put on and the system filled with ATF, which I know is bad since the system calls for aw46..and I understand it's a closed looped system but I'm not sure How to go about checking what's bad, a relief in the drive motors? Charge pressure not holding? Dealer not being friendly at all
Guessing it has two bad motor relief valves. Typically it's the forward valves on each side, somebody swapped them to make it go forward. Check charge pressure after the hydraulic filter, remove the pressure switch, use a 1,000 psi guage there. Should be above 200 and below 500 for all conditions. Test ports where the main hoses connect at the motors, use a 6,000 or higher guage one port at a time, at about one third throttle with parking brake on actuate steering, as the needle swings up, the reliefs should all pop at 5,000 psi give or take a couple hundred. Most parts are still available for it, even though it's gray market. Cheers, Lanway
For most practical purposes, ATF and ISO 46 hydraulic oil are equivalent. ATF has some goodies for the clutches and better anti foaming, oh and it's red. When you say "all she's got", do you mean the engine stalls, or the machine just won't move? Does the machine act differently when it's warmed up?
Here is as far as I know the only service information Morooka ever printed for these machines. https://www.dropbox.com/s/v5s33srietu40aq/Service Manual MST Series Rubber Crawler Carrier.pdf?dl=0
Must have moved on to the next emergency.....