not a tractor but it is hyd

[sam5570]

i am hoping to find some guys who have tow trucks or have worked on them? i decided to help a friend and install a new hyd valve box on his 1996 chalanger I 600 wrecker and now the wheel lift won't work everthing else works fine. there is a valve body on each side i replaced the one on the left witch does not control the wheel lift, the one on the right does that and thats what has me confused.

 

[Buppies]

Precision Hydraulics in Daleville Va is very knowledgable about such things and Steve there is very helpful Perhaps he can help or J J on this forum

 

[Tx Jim]

Check to see if you have the control valve in question plumbed in parallel rather than series? Can you post photo of control valves?

 

[sam5570]

thanks i will post some pics in a little bit.

 

[J_J]

i am hoping to find some guys who have tow trucks or have worked on them? i decided to help a friend and install a new hyd valve box on his 1996 chalanger I 600 wrecker and now the wheel lift won't work everthing else works fine. there is a valve body on each side i replaced the one on the left witch does not control the wheel lift, the one on the right does that and thats what has me confused.

Did you replace with same kind of hyd valve bank.

The wheel lift uses one spool, so take a look at that spool and see if it is providing fluid to the wheel lift cyl.

Install a hyd gage in the system and use it for trouble shooting.

It doesn't matter if the system is a closed or open center, as long as the hose connections are correct.

For test purposes, remove a hose from a spool that works and connect it to the wheel lift cyl and see if the cyl will lift.

 

[sam5570]

ok here are some pics not sure if you can make heads or tales out of them. i do know that the cylinders on the wheel lift has a valve to keep from droping a vehicle on the road in case you bust a hyd hose while transporting. there are 2 hoses that go to the valve body on the right side that runs the wheel lift, i have switched them around and nothing. JJ i can't use the other lines to test different sizes.

 

[sam5570]

oh yeah the pic of the old valve body the 2 crome plugs is where the lines connect and goes to the valve body that runs the lift. the valve body i replced is identical to the old one.

 

[Tx Jim]

It sounds as if the power beyond port isn't plumbed correctly. Maybe J_J will give his view point.

 

[J_J]

I really can't determine from the pictures that the valves have a PB port.

If the inputs and out port are connected correctly. then it is fairly simple to loosen a hose and flip the lever and see if that port is getting fluid.

If it is the same valve, then it has to be hose hookup mistake.

What ever spool does the lift, start the pump and flip the lever, fluid should flow out the work port for that spool.

The valve in the pic has a relief, so it is probably open center hyd, and the valves should be connected in series.

If the relief valve does not come on when all the levers are in neutral, you have flow to tank.

If you then move lever for a certain spool, the flow should be directed to that cyl.

 

[sam5570]

i am going now to make sure the line's are right but there are only 2 line's runs from new valve to the old valve one is connected into each end of old valve. i have switched the line's over on the new valve and makes no diference. no preasure at cylinders on lift just gravity flow of fluid.