Hi All, I have a 2017 TR340 and just got a new forestry mulcher that has a built in electronic flow meter. To my suprise when high flow or enhanced high flow is selected on the switch it is only putting out around 21gpm vs the 35-37 it should do according to the specs. I've checked all the fuses, tilted the cab and looked for any damaged wiring, reseated the connectors on the high flow solenoids, and confirmed in EST diagnostics that the computer is seeing the correct high flow switch position. The only thing I physically noticed was that one of the solenoid bodies rotates slighty back and forth...noticed this while trying to reseat the connector. If anyone has any ideas of what else to check I would appreciate it. From looking at the parts diagram description it looks like the solenoids on the high flow may be proportional so I'm wondering if maybe one/both of them are not opening completely. Thanks Kevin
IIRC there is a valve body located kind of around the rear of the engine, under the hystat pump. Seem to recall that when in standard flow only the main aux gear pump supplies oil to the control valve while the aux high flow pump just circulates back through the return side. When high flow is engaged then a solenoid on that valve combines both pump's flow together.
Thanks for the reply. I'll see if I can find the valve and the solenoids EST data point to make sure it's working.
The valves and solenoids appear to be working. The high flow pump is variable displacement and has proportional solenoids. According to pump manufacturer datasheet the solenoids start to open at 400ma and are fully open at 1200ma. It is working in the reverse direction and the computer is commanding 1248ma but in the forward direction only 864ma which explains the standard flow. Not really sure where to go from here.
I think you are looking at the wrong pumps. Your aux pumps are fixed displacement gear pumps. Standard flow has a single gear pump and high flow use a tandem gear pump (2 gear pumps in one pump assembly). The aux/high flow tandem pump will be at the very back of the pump group (closest to the front of the machine). The variable displacement pumps are only for the hydrostatic drive system and they are located closest to the engine.
On mine the enhanced high flow pump is nearest the engine and is definitely variable displacement. The A and B ports on it go directly to the high flow quick connects. I believe it’s this way because it has the “enhanced” high flow which is 4000psi.
The computer appears to only be commanding 20gpm in what it calls the forward direction. In reverse it commands full flow. I don’t see what would be causing that
Swap the mulcher hoses and run it in reverse and see what that does. If it works then you've got a fix.
I was able to confirm that with the enhanced high flow pump the male quick connect is high flow and the female is high pressure. The male connector high flows without the interlock jumped on the 14 pin connector. You have to jump the interlock to get high flow on the female connector. For my attachment I swapped the hose ends so that the mulcher runs in the correct direction off the male connector.
I just saw this. You need the jump with the 14 pin to use EHF.