Cat 308 Boom will not move

[Hogfarm]

Good Morning
The other day I was moving my machine and raised the boom to get by a tree. Now the boom will not move. The bucket works, it will travel and goes left or right . But the boom will not move, it will not extend and the thumb does not move. Where can I start looking for the problem?

 

[Gary Layton]

You need to provide more details...SN of machine, manufacturer, etc.

 

[Hogfarm]

2012 Cat 308C

 

[Gary Layton]

Good start but that is not the Ser. No. There are threads here that tell you how to find it. These guys need the SN to give you good answers. Ideally there is a tag on lower side of cab near the boom joint.

 

[Hogfarm]

CAT0308CVCRW00365

 

[Hogfarm]

I have had other machines but they were old and had handle to control the hydraulic controls, Silly me I wanted a machines with joy stick control,and don't know where to start looking for a problem, other than fuses

 

[Vetech63]

Do you know if the boom is being held under pressure? Does the engine or hydraulics sound loaded?

 

[Hogfarm]

There is no pressure build up,I let the machine set for a couple days and it bled enough for the bucket to sit on the ground.started it up like I said bucket, blade, travel and swing,work just fine

 

[Vetech63]

Did the boom move on start up without you commanding it from the joystick?

 

[Hogfarm]

No. I thought if the was any pressure,it might move a little on start up, but nothing

 

[Nige]

let the machine set for a couple days and it bled enough for the bucket to sit on the ground.started it up like I said bucket, blade, travel and swing,work just fine

Did you try the boom function at all after re-starting.?

 

[Vetech63]

It's just the boom and nothing else is acting out of the ordinary? I'm trying to determine if you have a fault in either of the primary systems that operate the implements..........the main control valve or the pilot system. If the boom didn't move at all on startup, then I'm thinking the main system may be ok.... unless it's hanging the spool on movement from possibly contamination. Usually once they are hung up, they won't recenter on their own unless the opposite pilot signal can overcome the drag on the spool.

Start the machine back up and attempt to move the boom again. Stop the boom in several places throughout the stroke with the joystick centering and notice if it still tries to move on its own. Make sure you notice any sounds that don't sound normal. Right now there isnt enough info to get an accurate picture of what may be happeneing.

Has there been any recent repair work done by you or someone else?

 

[Hogfarm]

I will try it again this morning, the bucket is on the ground and the boom is about a 1/4 of the way down. The boom, extend and thumb do not work. No one has worked on the machine got in it the other day raised the boom it went up and hasn't worked since I have a friend coming over Sunday to help me, by my self I can't run the sticks and get out and listen and look to see if any thing is trying to move

 

[ahart]

Does the machine have a pattern change valve? For some reason I’m unable to see any parts or service information on that serial number in Cat SIS. Anyone else have any luck?

 

[Tags]

If it does have a pattern change valve, any chance it is not locked into the desired position and has vibrated over a bit?

 

[Nige]

For some reason I’m unable to see any parts or service information on that serial number in Cat SIS. Anyone else have any luck?

Same here. It’s a 308C SR and looks like it’s a grey market machine although there is English language documentation for it listed on the Cat Publications website.

 

[Hogfarm]

Yes it is a gray market machine, but was told at the cat dealer no problem with parts. My friend came by today, looked things over. there is a little computer thing on the right hand side of the seat, where a person can program in where ya want the boom to stop. He said that is the problem. we opened a small cover and can see the manifold with 7 electric solenoid. tomorrow I will drop the pan under the machine and look for broken wire or another problem

 

[Hogfarm]

I can't find anything broken

 

[Vetech63]

there is a little computer thing on the right hand side of the seat, where a person can program in where ya want the boom to stop.

Can you take and post a pic of this? It's something I've never heard of apparently..

 

[Hogfarm]