Davis Model 185 Backhoe conversion to 3pt

[waggy5]

Hi, I have a Davis Model 185 Backhoe that I would like to convert over to run off my open system hydraulics from my tractor. The backhoe currently runs off a pto pump and has it's own small 5 gallon hydraulic reserve tank. The reason for the conversion is due to the difficulty in hooking the backhoe to my tractor and that the small 5 gallon hydraulic reserve tank gets extremely hot. My tractor has 16.1 GPM flow at 2755 psi. I hooked up the suppply and return lines from the backhoe to one set of remotes and used a bungee cord to hold the line open for hydraulic flow. The first time I did this I blew a small hydraulic bypass line. The tractor was idiling when this happened. I then made the repair to the line. I then bungeed the line down again to allow hydraulic fluid to flow. The lines on the dipper, swing arms, bucket,etc... all acted if they had fluid flowing to them under pressure. I tried to operate the backhoe and none of the controls would work. Any suggestions on what might be going wrong? I checked my feed and return lines for direction of flow and they are correct.
Thanks!!

 

[J_J]

Ever tractor owner should have a hyd pressure gage.

Do you know if you have flow through the BH valve. You definitely have pressure. If for some reason the return line was blocked by a loose QD, or connected wrong, then the valves open center core would be pressurized. Is the return flow from the BH going to reservoir. Try moving the 3pt lever and see what happens. Flow from all circuits should be flowing through the open centers, and back to tank with no lever engaged.

If the BH was getting hot before, then you probably have a relief problem. Clean the relief valves, and check the pressure.

You said that the BH was using a 5 gal reservoir, and since most reservoir are equal to the GPM flow, the BH valve may not be able to handle the flow, and you will need to set the BH pressure relief equal or 50 to 100 psi lower than the main relief valve.

You could reduce engine rpm when using the BH to reduce the GPM to an acceptable level.

 

[Brad_Blazer]

Are you sure you bungee'd the lever in the right direction?

 

[basilrobbins]

Did you ever get this problem solved? I just bought a 185 BH and want to operate it with a Case 595 tractor using the tractor hydraulics. I am also confused as to how the BH connects to my 3pt hitch, any thoughts would be helpful. I have the 2 sill assemblies ( 5-6 ft long square arms) and the 2 upper tension links ( 5-6 ft long 1 1/2 " round arms) but I don't know where on the tractor they attach