Good evening tractor folks and Happy Holidays ! I have a 1961 MF35 with a davis loader. When I last shut it off some months ago everything was fine. After having someone put new seals on the control valve to operate said loader ( it was leaking) the loader won't operate. After checking the control valve for a mistake in its repair it was decided to send the pump off to a bonifide pump shop. After weeks of waiting we were told the pump was no good as in beyond repair and we need a new one. That pump was delivered and installed and the loader still does not work. It seems as though it does not build pressure ( like it did before the new pump was installed). While running if you loosen a hydraylic hose fluid merely seeps out but does not spurt out as if under pressure. I think the new pump is no good but I wish any opinions from the experts out there. Thanks and best regards.
- Thread starter jimmyzie
- Start date
Sounds to me like your guy that did the valve repair probably go two lines crossed , Gave you checked the lines for proper placement? Simple replacement of o rings in loader valve should not have caused it to quit working IF it was working when you parked it.
We need to know it the hydraulic pump is a front engine driven one. If it is the control valve usually has a built in pressure relief valve. It could have been set wrong or installed wrong when the seals where replaced in the control valve. If the relief valve is not working then you will not have any pressure in the system. Also sometimes the front pumps can be hard to get all the air bleed out of them. It depends on how they are plumbed.
Steve@Advance
Well-known Member
If that is an open center valve system (probably is), it won't build pressure until a valve lever is pulled.
What happened to the old pump? Did it shed metal when it failed? If so, there could be shavings in the relief
valve holding it open.
Is there a suction strainer in the tank? Is it clean and submerged in oil?
When the new pump was installed, was the coupling installed properly? Could the key have fallen out letting
the pump shaft slip?
What happened to the old pump? Did it shed metal when it failed? If so, there could be shavings in the relief
valve holding it open.
Is there a suction strainer in the tank? Is it clean and submerged in oil?
When the new pump was installed, was the coupling installed properly? Could the key have fallen out letting
the pump shaft slip?
The old pump never showed signs of failure. Only after the contol valve was removed and new seals put in did the loader no longer operate. There was no "metal" issues that I could detect. The pump repair people ( 250 miles distant ) said the old pump was no good and sold us a new one. I did notice a hose or pipe in the fluid tank but have yet to determine how to get it out. The tank is basically the main frame of the loader on the left side which is about 12 inches wide on the bottom and tapers to perhaps 6-8 at the top and the control valve mounts to it. The valve is a Davis 101 if I recall. The shaft and key are intact and seem to be spinning just fine. Is a hydraylic pump made to spin a certain direction or would it build pressure in either direction ? Thanks
That Davis 101 would more than likely be the loader model numbers as they made 101s. As for you hydraulic pump. , Yes they do need to turn a correct way. they will have an inlet and discharge side. Post us a brand name and model number of the pump. Also a picture of the plumbing would help too. I think you got ripped off on the pump deal and that the control valve is assembled/plumbed wrong.
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