The K92 has an integral implement relief valve as part of the charge pump circuitry. As such, there is no need for a power beyond kit for the spool valve set. The pump flow goes to a priority flow diverter which splits off a dedicated approximately 2 gpm of the total flow specifically for the power steering. The balance of the available flow goes to the spool valve set.
That makes your project easy-peasy. No power beyond kit needed. Insert your new spool valve set into the return line from the original valve set.
> Original spool valve set > New spool valve set > Return to tank
Then run the work lines as required.
The circuitry is bit different in the 2305 in that the relief valve is integral with the spool valve. That situation requires the power beyond kit since the relief valve requires a dedicated return line back to tank. The return side of that valve is a largish chamber that incorporates both the return line port and the power beyond port. The power beyond kit seals off part of the chamber for the relief valve to dump excess pressure back to tank while allowing the flow to continue though for work beyond when the pressure is not excessive.
The charge system is set for 995 psi +/-72 psi as it comes from the factory. Max pressure allowed at the test port is 1502 psi.
With a 3.5" cylinder, you do not want any knots in the blocks at 1000 psi, and largish (over 12" in diameter) maple or birch may give you a hard time for splitting. Splitter head will move slowly, but most wood will split with a fairly short stroke. Birch is quite stringy and will usually require full cylinder travel, or an axe, to finish.
The auxiliary system on my GT will flow at about 2/3 throttle what yours will flow at WOT. The pressure is set for 1500 psi. That auxiliary system is totally separate from the hydro and is primarily for the loader, but the relief is set for the splitter.
I found the service manual for the K92 (with the hydraulic schematics
) by searching " tuff torq k91 service manual
Hope your 2305 isn't snow bound before you get back to it! How far north?
Awesome thanks for all your help!... and the links to the manuals!!
I found this on the web (a page out of TM1517 - tech manual for the 425/445/455), which shows the k92, but then also shows the rest of the circuit in the tractor.
So the transmission pressure rail is regulated by the charge pressure relief valve (set at 924PSI), but the charge pressure control valve is set to 284PSI, and that pressure goes to the power steering valve, and then daisy chains to the main spool valve?... which then runs at 284PSI?... that's it?... or does that valve remain open (no flow) unless the pressure goes above 284?...
would a T-connection on the pump output, and T-connecting to the return line give me better pressure and flow - due to fewer components in-line that reduce flow at pressure?
is a T-connection easier to make (and costs less) than a straight connection to an available port on some valve or pump itself?
When you say this:
The pump flow goes to a priority flow diverter which splits off a dedicated approximately 2 gpm of the total flow specifically for the power steering. The balance of the available flow goes to the spool valve set.
I think that's what the 2305 has, since it has a noted 2-flow rates: for power steering and for spool valve... but the 455 has a single port for both..... no?...
455 = 4.65gpm / 1000psi
2305 = pump flow 2.9, steering flow 2.3, total flow 5.2 (sum of the 2), split by a proportioning valve
So for the 2305 power beyond - does PB bypass the proportioning valve and provides the 5.2 total?.... or does it provide just the pump qty of 2.9.
if the latter, then the 455 should cycle the splitter faster than the 2305: ie 4.65gpm vs 2.9gpm
sorry for all the questions.....
the 2305 is about 120miles north of me, and down 10 mile really rough dirt road, across a wonky bridge, and 1 more mile along a rough ATV trail. it's a good 3.5-4hr ordeal to get it there or back. I fabbed up a heavy skid plate for the tranny, as the paths have lots of rocks protruding from the ground.
I need to move some dirt there, and I put a good dent in it yesterday, but had to come back before i finished. Top 2 feet is sand. Below it is rock-hard dry silt / clay. The BH with the 8" bucket struggled to sink in 50% of the 2 teeth-only (not bucket) into it... had to scratch it back and forth to have the teeth bite in a bit / loosen it up... then could begin to get the bucket into it to scoop it out.... 2+ minutes of scratching and scooping to get at best a half of an 8" bucket of soil excavated. I need to move 4-5 yards this way. I almost need a thin subsoiler bar instead of the bucket, to get more penetration pressure to break it up, then switch to bucket to excavate.
needless to say, I will be bringing another can of diesel with me next time I go up.