447 backhoe

jd670 · Mar 20, 2012

I have a quick question about my 447 hoe on my 3320. Noticed that the stablizer feet seem to leak down while I'm digging. I noticed this mainly over the weekend as I was digging on an uneven surface using the one foot to keep me level. Is this normal for the 447 or other JD backhoes or do I possibly have a leak somewhere? I haven't seen any fluid on the ground. Any help....

Martian · Mar 20, 2012

jd670 said:
I have a quick question about my 447 hoe on my 3320. Noticed that the stablizer feet seem to leak down while I'm digging. I noticed this mainly over the weekend as I was digging on an uneven surface using the one foot to keep me level. Is this normal for the 447 or other JD backhoes or do I possibly have a leak somewhere? I haven't seen any fluid on the ground. Any help....

I think you have a leak somewhere. For it to leak that fast does not sound right. Set it on concrete or asphalt if you have any and let it sit with the stabilizers up for a while and see if you can find a puddle anywhere or its just not holding.

toolbox5 · Mar 20, 2012

Sounds like cylinder leakng by , if there's no puddle

zr2blz · Mar 21, 2012

Are your tires loaded (mine are). I have same problem, I rebuilt one side (it was leaking on the outside). It was a little better for a while and now it's like the side I didn't put a seal kit in. Kind of wished now I had gotten the 448 ($1,000+ more). But, I do have lots of hours on mine (best guess 200 hours). I've rebuilt both swing cylinder also last year.

Jdman4x20 · Mar 21, 2012

From my dealing with backhoes. You will have a normal leakage rate that is published in the TM. I am not talking about a leak to the outside I am talking about threw the open center valve on the hoe.
You will need to measure rod travel on the cylinder and compare it to the spec.

Hope this helps.

J_J · Mar 22, 2012

Either your cyl is bypassing internally, or the spool for the stabilizers are leaking.

You can test the the cyl with a shut off valve in series with the base end cyl port.

Extend the leg, and shut off the fluid flow to the base end of the cyl. If the legs collapse then the piston seals are leaking.

When extending the stabilizers, does the relief come on or squeal?

A 3000 psi Hyd gage would let you monitor and trouble shoot the hyd system.

Something like this.

jd670 · Mar 22, 2012

Thanks everyone for the help. Yes my tires are loaded and I also have wheel weights installed. That could be a possible problem. Maybe overloading the cylinder. I will check pressure and the valves for leaks. When I bought my 447 it was with a 4210 tractor. The 448 hoe wasn't an option for the 4210. Pumps were only 2100psi instead of 2500 for the 3320. Dealer said not enough flow on the 4210. I bought the 4210 in July of 2005 as a leftover 2004 model. It was still new with only 4 hrs on it. The 447 hoe was $6200 counting the mounting hardware and power beyond kit. I believe the 448 was in the upper 7's. I am really happy with the 447. It digs really well with good power. It's done everything I've ask of it so far. PLUS....it's paid for.:laughing: