Davis 99 fel. Can I operate both levers at the same time

carpediem4570 · May 7, 2017

Good afternoon:

I have a Davis FEL mounted to a MF 65.

Iv'v been trying to move some cages full of firewood around and can't lift the load. (The wood might be too heavy with all the moisture in the wood. Seasoned wood cages I can move around). What I noticed is, when I try to raise the lift arms and operate the dump cylinder at the same time, the dump cylinder looses all pressure and I have to release the lever to raise the arms in order to get the dump cylinder pressure back.

The hydraulic fluid is full, there does not appear to be any leaks. I have synthetic hydraulic fluid in the tank, (its all I could get at the time) and I have a container of Lucas hydraulic booster and stop leak.

Without a load, raising the arms to about 30 inches and leveling the forks, the dump cylinder looses pressure and the forks tips are at 45 degrees within 10 minutes. The lift arms stay where they are.

If I raise the lift arms to 48 inches, it takes several hours for the dump cylinder to lose pressure and the lift arms stay where they were set.

As usual, any advice or suggestions would be gratefully appreciated.

P.S. How do you drain the fluid from the tank if you want to change the fluid?

Kind regards,

Carpediem

Sysop · May 7, 2017

With any hydraulics, the fluid is going to take the path of least resistance. If you are working with a limited amount of hydraulic flow from your pump, one operation at a time may be all that is possible. Sometimes turning the engine RPMs up to increase the flow is required to get more than one operation at a time. No matter the RPM and hydraulic flow, if you are maxing a control out, that will generally be the path of least resistance and leave little or no flow for any other functions. The key to using multiple functions is to only move the controls enough to get the movement you want, then adjust the RPM/flow to get the speed you want. Try using a real light touch on the lift while dumping.

Beyond that is operator skill; the "feel" and "touch" needed to feather the controls is something that takes practice. Couple in the fact that the "feel" changes with various loads in the loader and requires a different "touch" to properly feather the controls to control the load as desired, it takes a LOT of practice. Even the most experienced loader operator will get an odd weight in their bucket and need to readjust their operation to the load as they go.

Above all else is the quality of the valves. Some valves are simply easier to operate than others. Some seem to go from no flow, to a trickle, then full flow with the slightest movement of the control. Others allow a nice smooth increase of flow as you move the control.

shaeff · May 8, 2017

carpediem4570 said:
Good afternoon: I have a Davis FEL mounted to a MF 65. Iv'v been trying to move some cages full of firewood around and can't lift the load. (The wood might be too heavy with all the moisture in the wood. Seasoned wood cages I can move around). What I noticed is, when I try to raise the lift arms and operate the dump cylinder at the same time, the dump cylinder looses all pressure and I have to release the lever to raise the arms in order to get the dump cylinder pressure back. The hydraulic fluid is full, there does not appear to be any leaks. I have synthetic hydraulic fluid in the tank, (its all I could get at the time) and I have a container of Lucas hydraulic booster and stop leak. Without a load, raising the arms to about 30 inches and leveling the forks, the dump cylinder looses pressure and the forks tips are at 45 degrees within 10 minutes. The lift arms stay where they are. If I raise the lift arms to 48 inches, it takes several hours for the dump cylinder to lose pressure and the lift arms stay where they were set. As usual, any advice or suggestions would be gratefully appreciated. P.S. How do you drain the fluid from the tank if you want to change the fluid? Kind regards, Carpediem

Davis/MF 99, 101, and 102 you can only operate one lever at a time due to the design of the system.

You can check your pressure relief valve setting with a T fitting and gauge. I need to do the same on mine (also a 99 but with DA lift)

As for your leak down, packings/seals in the dump cylinder could be leaking. I'd check that and relief valve setting.

jimmysisson · May 11, 2017

30" seems like a normal height to have the loader when you're not using it. Maybe the rods or seals are worn more at that area? I seem to remember my ~'56 Massey Harris 50 you could use both functions at once, but they robbbed flow from each other. Though that was a time far away, same galaxy. Jim

jimmysisson · May 11, 2017

Rods, not Rida, whatever that is Jim. Sorry, looks like my edit went through after all

shaeff · May 11, 2017

I could certainly be wrong about not being able to use both at once. Anytime I've tried it sounded like the relief valve opened. It sounds like a squeal/hiss. Maybe that's just what it sounds like when it splits the flow as well?

Got me. I just use one at a time and get by just fine with it.

carpediem4570 · May 14, 2017

Hello and thank you all for your replies.

I think I will just have to start diagnostics now based on your suggestions.

Work through them one at a time until I find the problem.

Will report back.

Regards,

Max