Help needed, I need a pto pump for my backhoe, 15 hp iseki, cant find any info

[chrismac]

All, I wonder if someone could let me know what hydraulic pto pump I need for my 15 hp iseki tx 2160 with polymark beaver backhoe and (front loader which is driven from the tractor hydraulics)

I need to ask as there was none on my tractor. if I knew what pressure and flow rate I need I could ordr the replacement,

Any help greatly apprecated.

Chris

 

[Dave M7040]

You can work your problem backwards..... how much hydraulic fluid power can your 15 HP pto drive.

2,200 psi and 11 US GPM requires 14 HP

If you lived in the USA, this is the pump I would suggest.

https://www.northerntool.com/shop/tools/product_200737797_200737797

The relief valve in the backhoe control will protect the hoe if 2,200 psi is too high.

Dave M7040

 

[chrismac]

Thats a great pointer, would I be looking to max out on available power (hp) or come slighlty under a leave a little in reserve,

Thanks for your answer.

Chris

 

[Rich B1]

You need some n reserve. You on稚 want the engine working at it痴 limit all the time

 

[Dave M7040]

Thats a great pointer, would I be looking to max out on available power (hp) or come slighlty under a leave a little in reserve,

Thanks for your answer.

Chris

Chris

Your backhoe system will be an Open Center Hydraulic system.

The significance of this detail is that until you move a control, oil is flowing through the pump, then the BH valve and back to the reservoir using very little power.

When you move a control, then flow is directed to a cylinder and during that period, the power demands of the pump increase.

If you want to buy a factory made pto pump setup then you have limited control over exactly what flow rate and maximum pressure you will be producing.

Your control over the system's power requirements comes with the BH relief valve. If you do not have enough engine power you can slightly lower the relief pressure.

If you find your tractor is grossly under powered for a pto pump you buy, then a flow divider can be added to the pump output.

The flow divider can send a quantity of pump output back to the reservoir so that the power demands on the pump are lowered.

Dave M7040

 

[ericm979]

The 7.5' factory backhoe on my Branson works plenty fast at 2000 rpm on the engine. At 2500, the pump flows 10 gpm. The BH's hoses are all 3/8, so they're sized for less than 10 gpm of flow to the cylinders. Same with the loader.

If you go by the chart I'll link below, 3/8 hose and fittings at the suggested velocity for pressure lines is about 4 gpm.

Flow Capacities of Hose Assemblies


Another way to figure out the flow you need is to calculate the internal volume of the cylinders, and decide how long you want it to take to make a full motion, then convert that to GPM. Don't forget that with a BH you often to two or three motions at the same time, though they might not be full range.

 

[chrismac]

Chris

Your backhoe system will be an Open Center Hydraulic system.

The significance of this detail is that until you move a control, oil is flowing through the pump, then the BH valve and back to the reservoir using very little power.

When you move a control, then flow is directed to a cylinder and during that period, the power demands of the pump increase.

If you want to buy a factory made pto pump setup then you have limited control over exactly what flow rate and maximum pressure you will be producing.

Your control over the system's power requirements comes with the BH relief valve. If you do not have enough engine power you can slightly lower the relief pressure.

If you find your tractor is grossly under powered for a pto pump you buy, then a flow divider can be added to the pump output.

The flow divider can send a quantity of pump output back to the reservoir so that the power demands on the pump are lowered.

Dave M7040

Thanks for taking the time to explain, thats a great help.

Chris

 

[chrismac]

You need some n reserve. You on稚 want the engine working at it痴 limit all the time

Thanks for that, I'll see whats available in the UK.
Chris

 

[chrismac]

The 7.5' factory backhoe on my Branson works plenty fast at 2000 rpm on the engine. At 2500, the pump flows 10 gpm. The BH's hoses are all 3/8, so they're sized for less than 10 gpm of flow to the cylinders. Same with the loader.

If you go by the chart I'll link below, 3/8 hose and fittings at the suggested velocity for pressure lines is about 4 gpm.

Flow Capacities of Hose Assemblies


Another way to figure out the flow you need is to calculate the internal volume of the cylinders, and decide how long you want it to take to make a full motion, then convert that to GPM. Don't forget that with a BH you often to two or three motions at the same time, though they might not be full range.

Thanks thats a great bit of info there.

Chris

 

[lostcause]

The BH7500 backhoe I had on my JD770 (~24HP engine) was powered by a 6 GPM PTO pump installed by the dealer when it was new. Not sure what size backhoe you have, but that tractor looks to be about 60% of what the weight of my 770 was, so I would assume 6-6.5 foot backhoe roughly, so I would assume that nearly any pump 5 GPM or larger would do fine? Also, the rough rule for PTO pumps I have seen is 1.5 PTO HP per GPM of pump size. As a guess I'd say the tractor is 12~ish PTO HP, so around an 8 GPM pump might be the max you would want to run?