M816 Boom Cylinder Lock Valve

[Jersey4x4]

Does anyone know what happens to the boom on the M816 if a hydraulic line blows? Yes I know oils everywhere but on my Civilian equipment they have lock valves that hold the cylinder in place if a line blows to prevent the entire load from dropping. Does the M816 have any lock valves in the system? I did not see anything in the TMs about lock valves. I was loking for first hand info so I could be a little more reactive in case it happens or keep a closer eye on the lines. I just did a major PM on the boom and greased the snot out of it and changed the hydraulic oil and filter and lubed the cable and slides but am starting to use it almost daily and want to be prepared. I was not prepared for the 75 gallons of hydraulic fluid for the oil change and dont want to do it again any time soon.

 

[73m819]

just looked at the -34-2p, don't see any pilot check valves, not saying not there, just I could not find

 

[12Bravo]

I can't remember if the 816 has them, but I do know that the 936 does. I'm pretty sure that the 816 does, check the manuals to make sure. The Army is pretty good about load tests and the safety of lifting equipment.

 

[gimpyrobb]

My M62 has them, I bet the newer ones do too. Not sure what they are called, but they slow the descent, not stop it

 

[Jersey4x4]

Yea, I looked through the parts and service and the Austen Western manual and it does not say anything. I cant imagine it not having them but they could be built into the cylinders. I had a lift and the cylinders had them built in to the ports. I figured somebody maybe blew a line at one time and new first hand what happened

just looked at the -34-2p, don't see any pilot check valves, not saying not there, just I could not find

 

[73m819]

the austen western was used on the 819, a garwood is used on the 816

 

[gimpyrobb]

I know mine has them and they are not in the cyls. I had a main hose burst and the multi motor that was on my boom hook, all the way out and all the way up, came down. It was faster than I wanted, but it WAS restricted.

 

[Andydieselpower]

They might have an orfice restricting flow on the retract side. We use these on alot of our tailgates at my job some which weigh 8,000lbs and they work well. They hinder performance a little but are a cheap way to reduce rapid decent in case of hydraulic line failure, etc.

 

[m816]

I seem to remember that there are flow restrictors built into the valve body. We were concerned about way back then but we were driving the M543 at the time and had just switched from the M62's so the memory may be a little fuzy so don't flame me too bad if I am wrong.