641 with a 771 loader. Front mounted hydro pump gpm

Mike Elder · Apr 23, 2014

my loader pump is leaking badly. Also my control valves have started to seep. I found on my pump a model of H77AR1B. Seems to be made for many loaders and was used on the 772 series loaders. So I think this one has been replacement for the original pump. I am third owner of this tractor.

Anyways...I found another pump of the same model that is new, but I can not find anything telling me the specs of this pump. Does anyone know the GPM this pump is rated for? Or the loader? I found some control valves that will work, but they are rated at 9GPM and I dont have a clue what this pump or loader are rated at.

Any help would be greatly appreciated!

Sean in PA · Apr 23, 2014

You don't have to match the gpm of the pump to the gpm of the control valve. Most loader pumps will provide more gpm than the control valve is rated for. Most front mount pumps used for loaders on tractors will provide 12 or 14 gpm, and some up to around 22 or 24. Most control valves are rated for less than the pump. You just don't want to have a drastic difference, like a 30 gpm pump with a 7 gpm valve, as that can cause things to heat up over time and shorten the life of the fluid, and then if the fluid isn't changed often enough it can shorten the life of the seals in various parts of the system.

You should be able to replace all of the o-rings and seals on the control valve for fairly cheap money, and if you don't feel confident in doing it yourself, you can take the control valve to any good hydraulics shop and have them replace all them for a lot less than buying another valve, and that should last another 20 or more years before it starts leaking again.

641 with a 771 loader. Front mounted hydro pump gpm

Mike Elder

New User

Sean in PA

Well-known Member

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