altec lb650a problem

[greg250]

Hi I have a major problem with the boom the rotation works for a few minutes then it goes with gravity and boom spins that way.I hear the gear box motor running when we hit the valve but it sounds like it's under an enormous load.All other controls are fine. I know there is the valve on the side of the motor.Also maybe the spring break in the gearbox. from what i understand the spring brake is what allows the boom to move when the hydraulic pressure is released by the person hitting the lever then you let off the lever and pressure builds and doesn't allow the boom to rotate. I took the little hose off the valve that goes to gear box and when you hit lever you do get pressure.So what would brake in the gear box that would allow the boom to be able to be manually pushed by hand with no pressure pushing back?And obviously the truck is downed so I hope to fix it A.S.A.P. also looking for somewhere to get the parts near southern new jersey.

Thank you for all your help

 

[greg250]

came up with only 1 sulution

If you have the truck on level ground take the boom out of the cradle everything works fine but you can physically push the boom without touching controls.I am probably going to rebuild the rotation brake assembly. motor works fine all valves are working and the hydraulic pressure coming out of the manifold on the side of the motor going to the brake seems good. 1 thing left the brake

 

[lone wolf]

If you have the truck on level ground take the boom out of the cradle everything works fine but you can physically push the boom without touching controls.I am probably going to rebuild the rotation brake assembly. motor works fine all valves are working and the hydraulic pressure coming out of the manifold on the side of the motor going to the brake seems good. 1 thing left the brake

Call Altec in the AM I pretty sure they will try to help you.