pto pump to a mahindra 3710 backhoe

[Billself]

the pto pump is a prince 7gpm i used original hose to connect to pump pressure side then i capped off the power beyond sense its of no use to me. the hoe is a 3710b off a mahindra tractor i used a 10 gal fluid tank and a 3/4 hose from tank to inlet side of pump ,filter is on the return from controller to tank. the tractor is a ck20s standard with a pto hp rating of around 17hp i think, so i think the pto should handle it also i ran the PB into a bucket and tried it again and it didnt put any strain on pump but didnt have enough pressure to move the hoe around so i dont know if i could run it back to tank without more knowledge of the relief valve and how it runs.. if i could cut the flow of the PB to give me more pressure to the hoe then that might be a way to go if i could do that through relief valve dont know

 

[100 td]

........then i capped off the power beyond sense its of no use to me

Maybe reread my earlier posts. You can't cap off the PB, it has to flow to tank. Unless you pull the PB section of the valve apart and remove the sleeve or what ever they have in there to change the configuration back to a non-PB valve, which allows the flow to return to the tank line internally.

 

[Billself]

if i use the PB and run into bucket it dont bog down pump but dont have enough pressure to run the hoe? will that change if i adjust the relief valve or something else?

 

[100 td]

Hydraulic flow basics...............
Open centered pump/valve configuration
Constant pump flow, ALL the time
Pressure line into valve, flow goes through valve to PB port and exits to next valve in line.
When you use a valve, you redirect fluid to the work port out to the cylinder, and the other side of the cylinder discharges it's oil to tank. When the cylinder get to stroke end, the relief valve allows flow over set pressure to tank. In normal operation, every valve centered, flow in via pressure line and out via PB port (if it is a PB valve)

 

[Billself]

never messed with PB before so dont quite get it but when i tried uncapping it and running it to a bucket it didnt stall tractor but didnt have enough power to move the hoe around so what am i missing?

 

[100 td]

When a valve is operated to a work port, it redirects the PB flow, meaning when you select dipper out, all flow goes to the dipper cylinder, no flow continues out the PB port.
Look up some pictures of valves online and look for the PB modification, lots of valves have a plug on the side of them and you insert a sleeve or different shaped plug to change them from non-PB to PB. I cant recall Mahrindras setup, bit on Kioti (I think) it's a simple matter of undoing the PB plug and swapping it's position with the blank plug on the valve. Have a search in recent Kioti or Mahindra forums, I don't have time to look now.

 

[100 td]

never messed with PB before so dont quite get it but when i tried uncapping it and running it to a bucket it didnt stall tractor but didnt have enough power to move the hoe around so what am i missing?

The bit you are missing is You can't cap off the PB

when i tried uncapping it and running it to a bucket it didnt stall tractor

So it took the load off the the pump. When you cap it problem returns.............

 

[Billself]

so if i uncap PB then how do i make it have enough pressure to work the hoe?
because when i tried uncapping it the hoe didnt have enough pressure to work it?

 

[100 td]

when i took it apart top part of valve was screwed all the way out then as i took the top part out they put a washer under main bigger spring

but didnt have enough power to move the hoe around so what am i missing?

Well it was probably set up OK before but now..............

 

[Billself]

why would they put a washer under the big spring under the top spring and then leave the top spring loose? on relief valve