400S JLG boom hyd leak

[southernman13]

Don’t have the s/n right off hand but it’s like 2008 ish. Deutz 4 wd. Standard unit. I believe the telescope cylinder hoses are leaking. I can see the end of the cylinder just inside the boom and it’s not coming from there but theirs hyd oil comiing from inside the boom. When I boom in it out it leaks. So how difficult is it to rehose or pull the telescope cylinder. Either way sounds like more than I wan to do lol.

 

[arachels706]

Both hoses are at the rear of the cylinder, accessible by removing the cover on rear of the boom. Should be able to identify the leak with the rear cover off. Cylinder does not have to be pulled to replace hoses.
If cylinder does have to be resealed, worst part will likely be getting the front pin out. Good chance it is seized in the boom and/or rod eye.

 

[southernman13]

Ok thanks. I was thinking if there’s a holding valve on that cylinder it could have a leaking o ring. It just doesn’t seem like a hose leaking. It’s not spewing out like a ruptured hose. I need to get a good light and look in from the back. I can the front where the rod comes out or the cylinder and it’s not leaking there.

 

[southernman13]

I just looked a pic of the cylinder it has what looks to be a holding valve w probably a counter balance valve and a couple plugs on it. I bet it’s coming from there. Not sure if I’ll be able to see or access that from the back. I’ll have a look tomorrow. Thanks

 

[southernman13]

Well definitely the telescope cylinder is leaking. I replaced on hose on the back of cylinder that was showing wire and it had fluid on it but it wasn’t the culprit. Started it up ran tele in and out and it spewing out the boom. I don’t know what I was thinking before I was looking at the gland in the basket level cylinder and thought I was looking at the end of the tele cylinder. Duhhh lol. Anyway looks like if the pins come out it would be taken out the rear of the boom ? Definitely more than I want to do especially by my lonesome. I know a couple guys that do some work for me that should be able to handle that. The slave cylinder is leaking and I have a kit for it so looks like it would have to come out anyway.

 

[arachels706]

Correct, cylinder is removed from the rear of the boom. Will have to telescope out some to remove the front pin, and will be two blocks holding the rear of the cylinder. I usually use a forklift to pull it out, and a couple forklifts or gantrys to catch the cylinder.

 

[southernman13]

I gotcha. I have a couple skid steers and mini x