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3444 Hydraulic pump search


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I am restoring a 3444 backhoe special with a 3141 backhoe mounted to it.  Stripping it down to fix leaks and broken stuff I discovered that the splines are about wore through on the main pump.  It's a 7/8"-13 spline shaft and two bolt flange which seems pretty common, but I cannot find how many GPM it is.  I know it's big because of the backhoe, but it also runs the loader.  I have IH owners, parts, trouble shooting, and service manuals for it, but no were does it give specifics for pump capacity; it says "see parts manual for replacement"  I found a few that were 30GPM, but that seems high seeing that the the loader has priority and the valves are the same as the red tractors.  In a few other posts I was told that running the 17GPM the tractor pump was about as much oil as you could squeeze through them.   What do you thing would be the worst case scenario with a 30GPM pump running things?  Would stuff move faster?  Would it stall the engine when running the backhoe?  Would it have problems at full throttle?

 

CNH doesn't even list the tractor on the online parts search and the pump number in the parts manual is NLA.  So I am at a loss.  Any ideas?

3444 splines.jpg

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Right. Your machine was built by IH's Construction division, so there wouldn't be anything on it at an IH Ag equipment dealer, and by extension, CaseIH.

International sold off the Construction division to Dresser in the early 80's before Tenneco bought the Ag division. Dresser pretty much wrote everything off but the dozers real quick so you were out of luck on factory parts 30 years ago. Dresser has since sold the equipment line to Komatsu, so there is really nothing of the original IH Contstruction line left.

You can cross engine and some driveline parts with IH Ag tractors of the time, but something like this you're just not gonna find. Luckily this is a standard pump. 17GPM is probably standard as you surmise. 30 would be faster, but I would not be worrying about the priority valves, as they only pull off what is needed for the functions they service. It's if the main circuit will take the remainder.

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1 hour ago, Matt Kirsch said:

Right. Your machine was built by IH's Construction division, so there wouldn't be anything on it at an IH Ag equipment dealer, and by extension, CaseIH.

International sold off the Construction division to Dresser in the early 80's before Tenneco bought the Ag division. Dresser pretty much wrote everything off but the dozers real quick so you were out of luck on factory parts 30 years ago. Dresser has since sold the equipment line to Komatsu, so there is really nothing of the original IH Contstruction line left.

You can cross engine and some driveline parts with IH Ag tractors of the time, but something like this you're just not gonna find. Luckily this is a standard pump. 17GPM is probably standard as you surmise. 30 would be faster, but I would not be worrying about the priority valves, as they only pull off what is needed for the functions they service. It's if the main circuit will take the remainder.

Ah, well that would explain why the part numbers in the book are NLA and don’t cross reference to anything.  The hydraulic valve parts are the same as the tractors; there are 2 for the loader and 5 for the backhoe.

Fortunately for me, you're right, I found out this is a standard SAE-2B pump. 7/8”-13 spline, 4” hub, 5-3/4” 2 bolt spacing, and threaded side 1-1/4 inlet, threaded side 1” outlet. The backhoe and loader valves have their own relief valves set at 2500psi, so a pump capable of that or more would be fine. I just don’t know the gpm.

A little faster would be ok, but I don't want so much that it stalls the little BD-154 because it's more that it can handle.  Someone told me that their parts book says it was suppose to be a 21 GPM Cessna, where mine is clearly a TRW, and not listed in the parts book at all ?.

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Anyone know anything about these pumps?  I have bought a lot of stuff from Surplus Center, but didn't know if these were china made?  It kinda looks like you can simply pick what will fit your purpose, so I was just curious.

https://www.surpluscenter.com/Hydraulics/Hydraulic-Pumps/Gear-Pumps/3-11-cu-in-Dynamic-GP-F25-51-S13-A-Hydraulic-Pump-9-12245-C.axd

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I sincerely doubt if you could get an new shaft put in the old pump at a hydraulics shop for that price.  I've used Surplus center stuff a lot too, never had a bit of problems, but not those pumps.   Look thru the "surplus" pumps they have too.  Some years ago I found some red painted IH pumps they had surplus and bought a couple for projects.

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