Hydraulic Help

[Scott Y]

Need some guidance here if possible, I installed a totally independent hydraulic system on a tractor, I installed a 12 gallon reservoir on the back of the tractor, I installed a gear pump on the very front of the tractor, front pulley has a hub to install a splined drive shaft, the pump is rated at 12.6 gallons at 1800 rpm, there is a 1" ID line going from reservoir to the pump, there is a 3/4" ID line from the pump to the valve, valve is a 4 position, open center valve, I have no pressure what so ever, cannot even hear the typical hydraulic noise , I tried adjusting the relieve valve on hydraulic valve, made no difference, I unhooked pressure line from pump to valve bank , with tractor running, oil came out but not much for flow, I guess I need to actually measure if getting 12 GPM out of pump , does not appear that reservoir is getting any return flow, can not visually see turbulence when looking thru fill cap, needless to say I am a bit stressed out, have a lot of time and money in this project, and trying to get loader on before winter, any pointers will be very much appreciated, I will look into it some more, I am assuming something wrong with the new pump, (complete system is new) it is suppose to be a CCW rotation, maybe they sent the wrong rotation pump? Thanks

 

[ptsg]

Sure looks like the pump is not rotating the right way. Definitely look into that. Looking from the front, what direction does the engine spin? CW or CCW? I would expect it to turn CW looking from the front.

Either way, that's a nice clean setup you built there. Great job!

 

[Scott Y]

I did check rotation, but I better verify this tonight, I am pretty positive the output shaft is turning CW, so ordered a CCW pump, at this point I am hoping that is the issue, could be they sent me the wrong pump, will look into that further, Thanks for your reply, I appreciate it.

 

[mrmikey]

Are both ports on the pump the same size, 1" and you bushed the pressure down to 3/4". If so could you have the lines reversed? Is the tank vented? Couplings are not slipping on the shafts?
Looking at the pic, (near as I can tell), if the engine is turning CW, the suction should be on the right, (passenger) side, left side as viewed in the pic. If not, I think PTSG has the answer..........Mike

 

[Scott Y]

Suction is SAE 16 , (RH) I am using 1" ID hose from reservoir to the pump, Pump outlet is SAE 12 , (LH) using 3/4 hose from pump outlet to valve inlet, both coupling halves are keyed and key is in place, not sure about reservoir venting, assume cap must be, but can check, yes shaft from crank is CW and pump is CCW, tonight going to hook pressure gauge up to one of the valve outlets to verify any pressure, then will make sure reservoir is getting return flow, then will check output of pump , and post my findings, Thank You Very Much for the replies.

 

[Seven Gables]

Could it be the pump mfg/seller intends for that pump to go on a tractor with CCW rotation as viewed from the front of tractor ? If this is the case you need one that is CW to work. All I can think of , everything else looks right.

 

[LD1]

Did you hook everything up and then add oil?

That is a LONG suction line for the pump. Might just be having a hard time taking a prime.

Id unhook the suction hose (with a clean bucket handy) and make sure the suction hose has good oil flowing TO the pump and get all the air out. Hook it back up and try again.

 

[mrmikey]

I just thought of something else, something that happened to me years ago.
I had made up an 1-1/2" suction line with crimped on fittings. As you make up a line obviously you have to push the barbed ends of the fittings into the hose. Unbeknownst to me, I had a piece of bad hose or else I did something wrong...somehow, and the inner liner of the hose had separated and I ended up shoving the barbed fitting in between the inner and next layer of hose. Took a few hours to figure that one out...........Mike

 

[PILOON]

Hydraulic pumps are great to push, but with a long suction line full of air and no oil to seal the very minor vane gaps they'd be a poor suction pump.
B4 chasing for faults I'd first off prime that suction line using a funnel.

 

[oldnslo]

Agree on making sure the pump is primed especially with that length of suction line.

Might be a silly question but.. is the inlet hose suction rated?

1" ID is approx 5 feet per second flow rate at 12 GPM. Typical recommended max is 4 Feet per second for suction lines. approx 9.8 GPM is 4 FPS on 1" hose. Doubt this is your problem but might be an issue if running in cold weather at full throttle.