D4C III Fresh rebuild- No blade hydraulics.

[PapaK]

Hello everyone, I just rebuilt the engine and popped it back into my D4C. She fired right up and everything seemed good to go but I had no blade functions. It is not the control lock out as it lets me go into gear and move back and forward. I can back drag the blade over a pile in float mode and it then I can make it stay raised that way. But I put input in to drop it when it's suspended it will go down. It did that when the machine was off before so I suspect that's not indicative of what's going on.

I never removed the gear pump from the frame and I pulled the engine off by just slipping it off the spline. The hydraulic fluid is full. My manual is really really terrible and very hard to search through but I found that there is a lift solenoid and a tilt solenoid and they are both tied to the same fuse (Fuse 2S6024 See attached). I think this is a good starting place but I actually can't find the fuse. I know that sounds dumb but if anyone can point me in the right direction I would appreciate it.

I would also appreciate it if anyone else had any other ideas. I am going to put a gauge on the hydraulics after I find this fuse. My manual is so bad I'm having a hard time seeing where to put the gauge too.

 

[Nige]

Without a S/N (can you post it) not sure if your machine is that advanced but can you get into Diagnostic Codes for the electronics.?

Again with a S/N the location of the fuse panel can be identified. Is it under the console by any chance.? Also you probably need an electrical schematic - again this needs a S/N to get the correct one. Can you see a pattern emerging here.?

 

[PapaK]

Sorry I meant to post it. 7SL00403

There are no fuses under the panel. I just had it off. I also had the right hand shroud off and nothing down there either

 

[PapaK]

I only have wrenches here up to 1 1/4” but I pulled off the the smaller hose on the pump and started it up and it had no pressurized fluid coming out. So maybe I’m not getting supply for some reason but I don’t have a wrench big enough to take the supply line off. It looks like 1 3/4”

 

[Nige]

Fuse panel. See view of cab below. Note View "B-B".



#16 is the fuse block. #21 and #22 (2 of each) are the fuses.

 

[Nige]

I only have wrenches here up to 1 1/4” but I pulled off the the smaller hose on the pump and started it up and it had no pressurized fluid coming out. So maybe I’m not getting supply for some reason but I don’t have a wrench big enough to take the supply line off. It looks like 1 3/4”

You probably need to bleed the suction line to the pump. If that requires a larger wrench than what you have right now you need more tools...........

DO NOT run the pump without getting oil to the guts of it. You could burn it up.

 

[Nige]

Do you have access to compressed air.? If so try this -

Remove the hydraulic tank filler cap and stick the he open end of an air line into it. Wrap a rag around the inside of the neck to somewhat seal it, but you are not looking for a perfect seal. Crack the valve just open, you only need a couple of psi. With air flowing into the tank start the engine and try operating the implements slowly.

 

[PapaK]

Thanks for posting these Nige. I don't know what's up with this machine but the fuses aren't in any locations mentioned in the manual. Neither the right side of the machine nor under the dash. The only place I haven't ripped apart is the left hand side of the operating station and under the seat.

I ran into the city and grabbed a 2" crows foot which allowed me to take off the supply line. There was tonnes of oil supplying the pump.

Next I decided to drain the oil and pull the pump. Once the pump was pulled, I started the engine for 2 seconds to visually verify that the drive gear was turning. It was.

I could not turn the hydraulic pump by hand and then I really reefed on it and it became loose. I can turn it by hand now. This is another thing I wish the manual went in to more detail with. Is there some sort of clutch in the drive gear assembly that was slipping when the pump would not turn? Is it possible all is well now?

I am wondering if I should open this pump up/get it rebuild? Or was it just seized in this one spot after sitting like that for a year and its good now? I'm tempted to put it back on but draining all the hydraulic oil is such a pain I don't want to do that just to pull it off again.

Thoughts?

 

[PapaK]

OK I ended up putting the pump back on and same results...nothing coming out of the discharge end of the pump

 

[Nige]

Thanks for posting these Nige. I don't know what's up with this machine but the fuses aren't in any locations mentioned in the manual. Neither the right side of the machine nor under the dash. The only place I haven't ripped apart is the left hand side of the operating station and under the seat.

Please post a photo of your machine S/N plate.

OK I ended up putting the pump back on and same results...nothing coming out of the discharge end of the pump

Try this, it may need 2 people. With the pump still installed remove the suction and delivery lines. Sorry you're going to have to drain the oil again. Then remove the rear cover from the pump. Watch the pump guts and have someone either bar the engine over or flick the starter. Do the guts move.?

Or was it just seized in this one spot after sitting like that for a year and its good now?

First time I'm hearing that the tractor had been parked for over a year. That puts a totally different complexion on things.

 

[PapaK]

 

[PapaK]

Problem solved. And it’s a dumb one.

Well I had a chance to get out at the property today. I couldn’t take the back plate off the pump as the 4 bolts hold the entire pump together but I was able to take off the fittings and verify the pump wasn’t turning.

Then I took the pump off and verified the spline drive gear was turning. It was. ….wait a second. Those splines look a little deeper than they should be.

Sure enough, when the new bearings were pushed in for the drive gear, the gear was installed backwards and was not engaging the pump

Thanks for all your help! I feel dumb but I’m glad it was something simple in the end.

 

[Nige]

It had to be something simple........

 

[Welder Dave]

Glad you got it fixed and the splines weren't buggered up from partial engagement.