3444 International Backhoe Hydraulic Problem

[Bryce0623]

I recently purchased a 3444 International backhoe. I am having problems with the backhoe. With the selector switch in the up position I can swing the hoe left to right, but any other function with the boom bogs the engine down and kills it. If I have the selector button up the hoe works great and the power steering is more responsive but i can't swing left or right. Any advice at where to start looking woulkd be great. I have included apicture of the valve.

 

[J_J]

The hyd valve in the picture is a selector valve for two circuits. How is it related to the BH? The BH should have all the levers/controls on the BH valve.

Can you describe the hyd flow path from the pump to tank?

This is the same valve.

http://www.surpluscenter.com/item.asp?item=9-6134&catname=hydraulic

 

[N8ghz]

I just put a selector valve like that one on my tractor. My tractor has a plate on it's 3-point lift valve that has two ports on it. I used to have to connect a jumper-hose between the 2 for the 3-point lift to work. I had added two QC's to those two ports for rear hydraulics and without the jumper hose, the tractor hydraulics would be dead-headed at the QC's check valves, causing the pump to go over the relief valve bogging the engine, also the lift didn't work. The jumper-hose solved that, by getting the oil back into the tractor valve, thus allowing the lift to work and unloading the pump as in an open-center arrangment. I added a selector valve just like yours and a T in the return line. P goes to P on the selector valve, and port A goes to the rear hydraulics P QC. Port B goes back to tractor Tank thru the Tee fitting I added. The Tank QC (rear-hydraulics) also goes to to Tee fitting. Now I push the knob one way when nothing is hooked to the rear QC's and the 3-point works normally. Pushing it the other way, the rear QC's are active. I have open-center things that run from the rear QC's, so being open-center, the 3-point lift also works as long as something open-center is connected. If nothing is connected, I must push the selector valve the other way.

Botton line on your problem, it sounds like you don't have a return to tractor-tank from the hoe in the one position that loads the tractor hydraulics down? Without seeing how all the hoe connections are done, I don't understand how some things on it work at all ?(and some don't)

 

[Bryce0623]

I will take some more pictures and let you guys look it over. The swing itself has a pump on each side of the boom. I had read in one location that the selector valve is supposed to transfer the power to the hoe in the up position and in the down position transfer it back to the power steering but it doesn't work that way.

 

[J_J]

Are you talking about a cyl on either side of the boom?

What you said about the valve shifting the hyd flow from steering to the BH would be logical.

Does the machine itself have two pumps, like one pump for steering and another pump for the rest of the hyd's.

Can you post the flow from each pump, and which valve port is being used for what?

Did the tractor originally come with one pump, and then divide the flow to the steering and the BH, or did someone add another pump just for the boom swing operation?

Do you have a separate valve for the boom swing cyl?

 

[Bryce0623]

It actually looks like a pump motor on each side of the boom with hoses. I will take some photos and post them tonight. I just bought this unit from a lady who lost her husband and he bought it at auction so I have no history on the machine, but she did say that he was trying to fix the same problem I have. There are two pumps on the machine.

 

[Bryce0623]

It looks like the selector valve just goes to the swing valve, the metal lines are the return and the supply. I have taken more pictures and made a crude drawing of the diverter valve to the Hoe controls. It has two pumps one on the side of the motor and the other in the front of the tractor. The Swing has a motor on each side of the boom.

 

[J_J]

I am not to sure that is a pump. If it is, what is turning it.

If it is a hyd motor, it could be turning a screw to turn the boom.

Could even be a hyd cyl to push or pull the boom.

I only see 6 spools on the BH valve, and they apparently are for the boom dipper, and bucket. There should be a valve for boom left, and right.

The valve up by the seat is a selector valve for two different circuits. If this valves feeds the BH, then it should go to another valve for left/right control.

 

[Leejohn]

On my brothers the selector valve is for the left and right movment and the power steering. I don't think it's hooked into the rest of the hoe movments. I could check his today and get back to you if you would like.

 

[J_J]

Do you have the service manual. Where to order

INTERNATIONAL 3414 3444 3514 Hydraulic Service Manual

This is the swing mechanism for a IH 3120, Looks similar.

I believe the cyl are push cyl that push the splined gear to swing the boom.

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=645024>

Hee is another manual.

http://cgi.ebay.com/International-H...-Operators-Manual-/220768838382#ht_1746wt_821