446 has no hydraulics!

[myerslawnandgarden]

I agree that this is a strange one and just my 2 cents....... I know the pump coupling was said to be replaced but in my experience a total no hydraulic complaint usually points to the coupling assembly.

Bob

[metalguy]

Ok, here is where I'm at: I accidently engaged the hydraulic PTO , and didn't notice it, then started the engine (My PTO has quick disconnects, no connecting hose between them) . What then happened was this: the engine started, and burst the hose that was on the outlet side of the new pump. What I got from this, other than having to buy a new hose, is that the new pump develops pressure. The second thing is that the hose that burst had had a good amount of damage prior to it bursting, and had been chafing against the frame for years, by the looks of it. So... here is what I think happened: I think this hose had a layer tat came loose inside, stopping flow, and because of that, I had a zero flow condition. Many of the tests were from just cranking the engine on the battery, and not actually running. I do know the PTO was not engaged this whole time, as I had checked it numerous times, and it was not. I must have bumped it in the crowded garage while swapping out the pump. I'll know more soon, but I am dead in the water until my new hose comes in. The takeaways are these: The new pump, lovejoy connecter, and all work, and provide pressure, so those can be ruled out. I will install the new hose when it gets here, and test again, then go from there. I am hoping it was the entire problem, but will see.... Someone asked how I drained the Resevoir before. I simply removed the supply hose from the pump side, and drained into a used oil container. I have not tested the old pump, and it is probably fine, and will check it later when I have time. Thank you all for the comments! Ruling out the relief valve due to no movement in the tank was excellent. It made sense, for sure. I have been looking through the diagrams in my shop manuals, and see how that all works out through the various items added to the tractor. Very helpful. --------Metalguy

[myerslawnandgarden]

Metalguy,

I do hope this solves your problem, but my question would be, if the high pressure hose lost some of the internal lining and is lodged in the tcv, then why didn't the hose burst when you first started the engine with the old pump and found that there were no hydraulics? Perhaps there was some oil flow, just not enough to get the tractor to move or give much flow to the the lift circuit but not a total blockage as to build enough pressure to blow the hose as dead heading the pto circuit did? Do you plan to disassemble the tcv to verify and clean then?

I would definitely recommend that you make up a loop hose with quick connectors to install between the work ports of your pto valve. It that lever gets caught on a tree branch for instance with the engine running at full throttle it doesn't just kill the engine or burst a good high pressure hose, the usual result is a pump split in half.

Bob

[ras101]

So just a thought...are you sure the pump is even rotating? I would check out the key has not sheared.

[metalguy]

Guys, the problem is solved. The line from the pump (pressure side) was the entire problem, it turns out. The inside had come loose, and caused a no-flow condition. I had already replaced the pump, so it has a new pump too, so I guess all has worked out ok. Thankyou all for your help, and advice! I guess things don't last forever, and need replaced from time to time. --------Metalguy