"eric wrote:

Im trying to lift a IH60 3 bottom plow with the 44 front mount pump but it wont lift it when the front dozer blade is on there it works fine even lifts the front of the d2 up is it because the cylinder on the 3 bottom plow is 4in bore and the cylinder on the d2s dozer blade is 8in bore our should i be checking pressures

Explain this again. The dozer itself works fine plow not involved. Now you hook up the plow, leave the dozer connected, divert some hyd flow to a new valves to run the plow. Where do you get the flow to the new valve. ?

How does the dozer do when the new valve is plumbed in?

The dozer prob has an open center valve so you have to figure out how to bypass that issue.

Hi,
as others have said you need a Crossover Valve to direct HPCU (Hydraulic Power Control Unit) oil to either the Blade or the Rear Attachment because you only have a single control valve HPCU that can only control one circuit at a time.
If you have only the Rear Att. connected, as pic 2 shows, it should work as the HPCU oil is being directed to/from the Rear Att. cylinder only.

If you have both the Blade and Rear Att, teed together it will not work as the blade cylinders have release valves in the cylinder pistons, that when the cylinders reach full travel in or out, will by pass HPCU oil thru the blade cylinders and back to the HPCU with only a little bit of back pressure due to the resistance of said action--the system cannot build up pressure due to the by-pass feature in the blade cylinders.

From memory this is done so the blade cylinders cannot be bottomed out as they need to move in and out in this condition with the track frame oscillation or they would be dead ended and blow a cylinder seal or hose when in the hold position--I stand to be corrected.

The Crossover Valve separates the two circuits (Blade or Rear Att.) allowing the use of either circuit only, if you like, only one circuit at a time dependent upon which circuit is selected.
You lift the blade--shift the Crossover Valve to Direct oil to the Rear Att.--the blade will stay raised--dependent upon Blade system leaks.


Scan below from a 44 HPCU OMI tells of Crossover valve use.

Hope this helps.
Cheers,
Eddie B.

"eric wrote:

Looking at these photo's, it appears that you have the system isolated from the Blade Cylinders? Only thing the small lines will do is limit speed (flow) not pressure. Pressure will get there to lift as flow is filling the cylinder slowly due to line size.