John Deere 445

bear4020 · Mar 26, 2015

new to the forum. I have a john deere 445. has about 886 hrs. goes forward and backwards just fine. But all the sudden I lost power steering and deck lift. Have not done anything new to it. Just need to know where to start. Any help would be apprecited.

beenthere · Mar 27, 2015

:welcome: to TBN

For starters, what is the history of the transmission fluid changes and the tranny filter change? Fluid level check out ok?

bear4020 · Mar 27, 2015

That is a good question. Really just come acrossed this mower and only owned it a short while. Now, the fluid level is right at the full mark. No discoloration or anything of that nature. Looking down in the unit itself looks pretty clean as far as I can see. I do plan on changing fluid and filter this weekend. That way I have a fresh start with it so to speak.

Gary Fowler · Mar 27, 2015

I think these mowers have a separate hydraulic pump to operate the steering and deck lift. Check out your pump. I assume they have shared reservoir with the transmission. I had the predecessor to the 445 which was the 332 and it had separate hydraulics including dual front quick connects.

beenthere · Mar 27, 2015

Here is the "theory of operation" from the service tech manual.

beenthere · Mar 27, 2015

Here is the hyd. flow chart. You may also find it very worthwhile to get a copy of the service technical manual and have a ton of information at your fingertips.

narampa · Mar 27, 2015

No they don't have a separate pump. The Hydraulics work of the same pump as the transmission charge pump.
Just finished assembling my trans axlel and I would have to say that the problem is a hydraulic problem only.
I am a mechanic and when I get a chance I will look into the problem if you have not solved it by then.
If it moves back and forth it is not an oil problem. Same pump same oil.
It sounds like it could be a circuit relief but that is only a guess. I don't have the manual in front of me.
Just don't panic and start ripping and tearing!

narampa · Mar 27, 2015

Just thought of what it is I believe it is a priory valve but again till I look at the manual I won't know for sure.
The steering has priory over hydraulics because of safety. I would have to say something is sticking and I bet it is in the hydraulic control valve where the hose couplings are on the left front.
Just hang in there and we will get you fixed up

bear4020 · Mar 27, 2015

Thank you all very much. I try not to tear into things till I'm sure I know whats wrong. Cant afford that. Lol. Single father with custody of my kids. If I have to push mow till Its solved then so be it. I'm truly blessed that it happened before mowing season started.

narampa · Mar 28, 2015

The hydraulic control valve where you hook up hoses,has two relief valves one on the top and one on the bottom. They look like a big plug. Remove one and clean it up. Be careful as they are spring loaded and have a seal,spring,and plunger. Make sure you remove the plunger and that it is free and clean. All it takes is a hair to hang them up.
Clean one and try it. If that doesn't work try the other.
I wish I could send the page from the parts book,but I am not great with computers.
Perhaps somebody else could post a picture?
Try that first and let us know how it went.
That would be the first step to trouble shooting your problem.
.

beenthere · Mar 28, 2015

The parts schematics are available to anyone, through jdparts.com and free registration to boot.
That will show the breakdown of the control valve assembly and relief valves.

Because the OP explained that the power steering is also not working, and that it is priority in line ahead of the hyd control valves, seems to me that the problem wouldn't be in the relief valves at that location. But may be worth a try to clean them up.

narampa · Mar 28, 2015

beenthere said:
The parts schematics are available to anyone, through jdparts.com and free registration to boot.
That will show the breakdown of the control valve assembly and relief valves.

Because the OP explained that the power steering is also not working, and that it is priority in line ahead of the hyd control valves, seems to me that the problem wouldn't be in the relief valves at that location. But may be worth a try to clean them up.

I agree except for the fact that from what I see any relief valve in the circuit will effect both. There is a possibility that I am incorrect. However the next step is to remove the fenders fuel tank and get into the valves on the trans axle. Like I said don't start ripping and tearing. Easy things first!

beenthere · Mar 28, 2015

:thumbsup:

bear4020 · Mar 29, 2015

Sorry everyone. Had some boar goats Have kids. Been really busy with them. Will be checking out Deere soon.

narampa · Mar 29, 2015

bear4020 said:
Sorry everyone. Had some boar goats Have kids. Been really busy with them. Will be checking out Deere soon.

I think we are all waiting to get this thing fixed. Than we can get back to sleeping again.

narampa · Mar 29, 2015

One thing I would like you to try. With the engine stopped and you turn the steering wheel do the front wheels turn left and right.
If the steering valve is working correctly the wheels should still steer. If not do not assume that the valve is bad. Unless the steering wheel is seized and will not turn at all.
But we should know this as the steering valve has a connection back to tank. So we have to know where the oil is going.
Let us know what you find.

bear4020 · Mar 29, 2015

Yes. Wheels still turn left and right with the engine off.

narampa · Mar 29, 2015

bear4020 said:
Yes. Wheels still turn left and right with the engine off.

If that is the case than I would like you to remove the circuit relief valves on the flow chart that Been There supplied.
One is in between the two upper hose couplings. It looks like a bolt head. The other one is underneath the valve.
As per my earlier post. Let us know what happens.
If this does not work you will have to remove the seat and fenders.
So far we know pump is good and steering valve is good. We now have to find out where the flow is loosing pressure.

narampa · Mar 29, 2015

Here is a picture of the hydraulic control valve that has the hose couplers under your left foot. As you can see there are two lift check valves. These are the ones I want you to look at.
The color of the flow is yellow just as in the previous pictures.Which is pump charge pressure. If either of the two check valves are unseated a tiny little bit they will not allow pressure to build in either the steering or the hydraulic lift circuits.