YM2620D - Loss of hydraulic pressure to rear 3 pt. and front loader bucket?

[Dick_Jermyn]

Thanks Kenmac for the reply.

This divider block/valve assembly has one feed pipe coming from the pump. There is three out lines from the block. One looks like a pressure unloader that goes back into the base of the hyd.filter. One goes back to the spool valve for the front bucket and 3 pt. piston. The last goes toward where the clutch pack would be found.

I plan to take off the pressure hose going to the bucket spool valve and see if good flow/pressure is shown when the engine is on. If so, I may have a blocked spool valve for the bucket and return line to the three pt. lift assy. piston. If the flow is not good the I can only assume that there is some kind of blockage in the splitter manifold.

I will let all of you know what I find. Again thanks for your input on this matter.

A man needs his tractor to work right!

 

[Xfaxman]

I suspect an air leak on the suction side of the system, Your new filter may be loose or not sealing at the rubber gasket.

 

[winston1]

Might help a little. http://www.tractorbynet.com/forums/...ebuild-hydro-diverter.html?highlight=diverter

 

[Dick_Jermyn]

Have been busy at work and no repair time. I pulled the suction lines today and found what I think is a undersize o ring in the coupling to the suction side of the pump. The casting grove is 3mm wide. The o ring is 2 mm wide. The O ring does not sit above the casting that mounts to the pump. This is where I may have an air leak to the system. I have ordered new o rings from Hoye. I took the pump off and will take it Tuesday to the local hyd. repair shop for their thoughts on the matter. I will keep you informed as I progress on this matter. To Much work and not enough retirement time. Ahhhhhhh. Dick

 

[Dick_Jermyn]

Finally got it..... I replaced all the o ring seals on the suction line from the sump to the pump. I also replaced the pump seal, pump mounting gasket and shaft ( HP side) o ring from the pump. Both the o rings at the pump seemed very thin. They had a blue dot on the ring side. I presume that indicates that they were made for high temp oil use. The old o rings measured about 1 1/2 mm thick. The gap that they set is was 3mm wide and 2 1/2 mm deep. The rings would not sit above the face of the grove. I suspect that air was entering the top of the pump (suction ftg.) and through the pump seal. I fit a 3 mm X 22mm thick o ring on the suction side of the pump and a 2 1/2 mm X 22mm o ring on the high pressure side of the pump. My thinking on the 2 1/2 mm o ring is that the high pressure would force the o ring into the gland grove under pressure. I removed air from the suction lines before starting the motor. I am looking forward to seat time after I finish installing a new seat.

Again, thanks for the input that you men gave me on this matter. Happy Holidays and Seasons Greetings. Dick