Pto pump flow help??

[countrybumpkin]

Have a subframe mounted back hoe , it has it's own hydraulic tank and pto pump. It's a bit to slow, need more flow rate. Any way the pump is a Cessna 24503 it's rated for around a 20 gpm but also it's rated for up to 3600 rpm , they have the pump mounted straight to the pto of the tractor so I'm only getting 540 rpm I'm trying to find out about what gpm I'm getting at that slow of a rpm. The hoe has a flow rate of around 16 gpm. I'm just guessing it's not putting any thing close to that out of the pump.

 

[jenkinsph]

I would agree with your assumption, your pump displacement times the rpm would give you the flow. I would say that changing the pump to something such as the Prince pto pump would be a better solution. Most backhoes will operate fairly well at 1500 to 1800 rpm engine speed, I occasionally operate my backhoe at higher rpms' and flow rates.

If you can determine the specific ratings on your pump you can get a good idea of what your flow rate really is.

 

[J_J]

New Eaton Cessna Hydraulic Pump 24503 Lax | eBay

This pump is a high rpm pump and will not pump 20 GPM off the PTO, which runs at 540 rpm, unless it is geared up .

How do you have it connected?

20 GPM at 540 needs a 8.6 cu in displacement pump and 41 HP.

20 GPM at 3600 needs 1.3 cu in displacement pump and 41 HP.

 

[jenkinsph]

This Prince pump is a good match for your needs. 7.8 CU IN PRINCE HC-PTO-9A PTO PUMP 540 RPM

 

[countrybumpkin]

New Eaton Cessna Hydraulic Pump 24503 Lax | eBay This pump is a high rpm pump and will not pump 20 GPM off the PTO, which runs at 540 rpm, unless it is geared up . How do you have it connected? 20 GPM at 540 needs a 8.6 cu in displacement pump and 41 HP. 20 GPM at 3600 needs 1.3 cu in displacement pump and 41 HP.

That's what I was afraid of after looking at what info I could find off the net. I bought the setup as is, they took that pump and mated a 540 pto coupler straight to it, no gear increase so I'm only getting the 540 like you said so I'm not even getting close to rated output gpm. I've done a bit more searching and found a increaser that the pump bolts to and then it hooks to your pto but not able to find a price, but I'm guessing it's not cheap. I even thought about building my own increaser or just going a head and buying a new pump like the one in the link.

 

[jenkinsph]

For about $600 you can buy the Prince pump I listed above with the torque arrestor kit and shipping included. When you think about installation and removal this will be way easier to deal with. The pto hp is a perfect match to your tractor and will allow you to operate at speeds from idle to full speed with a workable flow rate. While it is more money it is a very good match for your tractor and backhoe.

 

[countrybumpkin]

Thanks , I'll definitely look into that, really need to have it working a bit faster. Here is a pic of how they have the pump connected now pretty simple just a pto adapter and a plate cut to straddle the drawbar to control the torque

 

[J_J]

Can you provide us with a model number and brand name from the pump?

 

[countrybumpkin]

Cessna. 24503 LZA

 

[J_J]

24503 LZA

Your pump turns left.

Displacement is 2.1 cu in

Input rpm max is 2500

Max pressure 2000 psi

Requires 32 HP for max GPM

23 GPM flow

Who put your system together?

It is the wrong pump for PTO work. However, you can still use the pump.

At 540 PTO you get 5 GPM, and requires 7 HP.

At 1000 PTO you get 9 GPM, and requires 12 HP

 

[countrybumpkin]

Thanks J J that's pretty much what info I was looking for. I don't have any ideal as to who put the setup together I bought the tractor with the hoe already setup it had 100 hrs on the meter back when I bought it. I've used it all these years the way it is, works pretty well it's just slow. We just bought a new house and more land and will be using the hoe a lot more now so I thought It would be a good time finally to check on doing something with it.

 

[J_J]

Do you have optional PTO speed like 1000 rpm?

If so, you can get 9 GPM at 2000 psi .

 

[countrybumpkin]

No I sure don't , I will have the hoe back on this week end for a couple thing I need done. I'll get some pics and measurements, and see just how much room I have may be possible to come up with some type of speed increaser for a lot less than a new pump.

 

[J_J]

Your tractor hyd is 7 GPM, so I think I would use the tractor hyd.

You will then have more GPM's and pressure to the BH.

Set your BH relief to the same as your FEL valve.

If you can find a 4.5 ratio gear box you can use the 540 PTO to increase the so called PTO pump to the rated 2500 rpm

Since you have 27 PTO HP, you can run the tractor PTO pump to pump 20 GPM at 2000 psi.