PTO pump stalling tractor .

Swamp Rooster · May 26, 2019

Do you all think the smaller pump would work .. They have one that is 7.4 gpm .. at 540.. maybe that would work? I was told that they bigger pump would not be a problem if I just idled it down but it just is not working well .. I did find a presser relief valve but it was a none adjustable .. said 170 on the top of it .. The pump does not have one. Thought i would see if I could find a replacement for the 170 that had adjustment.
If any of this helps this is what my loaders book says . it is a Nokka 29 log loader ... max working presser .. 17.0 MPa Recommended hydraulic pump capacity 30 l/min .

oldnslo · May 26, 2019

Swamp,
17 MPa = 170 Bar = 2,465 PSI
30 L/mon = 7.9 GPM

To figure HP = GPM x PSI / 1714 x efficiency

in this case 7.9 x 2465 / 1714x.85 = 13.4 HP

I suspect the 170 on your relief is 170 Bar so that would be correct for your machine. Problem is that when idling your tractor down you lose HP. From the information you have provided the 7.4 GPM would be a better solution for your application.

Swamp Rooster · May 26, 2019

oldnslo said:
Swamp,
17 MPa = 170 Bar = 2,465 PSI
30 L/mon = 7.9 GPM

To figure HP = GPM x PSI / 1714 x efficiency

in this case 7.9 x 2465 / 1714x.85 = 13.4 HP

I suspect the 170 on your relief is 170 Bar so that would be correct for your machine. Problem is that when idling your tractor down you lose HP. From the information you have provided the 7.4 GPM would be a better solution for your application.

I think I will order one and give it a try . I wonder if they could give me some credit for this pump I just got from them . It does not have ten minutes use .. lol ..
oldnslo Do you think this one would work ? Dynamic Hydraulic Tractor PTO Pump GP-PTO-A-3-6-S 7.4 GPM @ 54 RPM 9-892-3 | eBay

buickanddeere · May 26, 2019

Swamp Rooster said:
Hello every one . I was talking last week about getting a PTO pump to rum my log loader . I did and I went with this pump 16.6 gpm at 540 rpm . I have it all mounted , made a bracket for it . It seems to want to really work the motor on my Tractor to run the pump . The loader requires 9 to 11 GPM to rund . I was told that I could just idle my motor down and the pump would handle it well . Even at 2000 and 540 it really lugs down..
I was thinking that I was trying to move to much volume of oil ? Thought the pump might be to big .. Any thoughts .. I will try and post some pics .. Tractor is a TC33 Browser no longer supported Browser no longer supported 7.62 cu in 16.6 GPM 54 RPM Dynamic GP-PTO-A-7-6-S Hydraulic PTO Pump | Dynamic | Brands | www.surpluscenter.com

Using a closed centre valve on an open centre pump ?

Swamp Rooster · May 27, 2019

buickanddeere said:
Using a closed centre valve on an open centre pump ?

I think my system is open. The oil flows as long as the pump is turning .

buickanddeere · May 28, 2019

Design error.
Why do you want to idle down the tractor ?
If you want high gpm and high pressure . It takes power .
How about a 2stage pump ?

Swamp Rooster · May 31, 2019

buickanddeere said:
Design error.
Why do you want to idle down the tractor ?
If you want high gpm and high pressure . It takes power .
How about a 2stage pump ?

I could not find a two stage PTO pump ..

Swamp Rooster · May 31, 2019

Just wanted to say thanks for all the advice . I did order a new pump , I ended up going with a smaller GPM pump . My Uncle could use the bigger one so I gave it to him. Hope this cures my issues . Thanks again and I will let you all know how it goes.