newb JD400 hydraulic problems

[JD400 ind]

G'day all!
Please bear with me i am new to this old tractor caper.......
I have just bought a JD400 loader backhoe and she has some hydraulic system issues. the loader bucket will only raise very slowly when the engine is at highish revs, it will rasie about 4 inches in a minute or so but dosn't seem to go any higher???

The hoe also operates very slowly but does eventually reach full travel/extension and returns slowly but does go all the way home? The slew drive has been by-passed and the previous owner said that a seal was bad in the drive.

So... my questions are, does anyone have some ideas what may cause the above symptoms? Are the slew seals difficult to locate? It seems a fairly straight forward job to remove the hoe for changing out the seals.

I don't have the machine at home yet but can't wait to start tearing her apart.......

Thanks in advance for any replies

 

[J_J]

I would start out by checking the fluid levels and maybe changing out all the filters and determine if it has the correct fluid.

I would also install a 3000 psi gage in the hyd flow path and use it to monitor and trouble shooting the hyd system.

If it uses QD's, make sure they are passing full volume.

JD 400 Hydraulics


Hydraulics:
Type: closed center
Capacity: 10.75 gal [40.7 L]
Pressure: -unknown-
Valves: 1 or 2 optional
Total flow: 6.5 gpm [24.6 lpm]
13 gpm [49.2 lpm] (optional)
28 gpm [106.0 lpm] (optional)

http://www.tractordata.com/industrial-tractors/000/0/1/16-john-deere-400.html

 

[JD400 ind]

Thanks JJ, when i get the machine home i'll be able to get some diagnosis done, I'll have to get my hands on a test gauge......

Cheers Phil.

 

[JD400 ind]

Well today i got some hyd/trans oil gathered some tools and traveled the 160km in 35 degree heat to where the 'hoe resides. I put a new battery in her so she'll start off the key and got her going, hydraulics super slow, no different to last weekend when I bought her.

Shut her down and found the trans dipstick by right ankle, checked oil level - way over-full!!! hmm, it's not a lack of oil then, i'll check the sludge screen...... climbed under her and looked by the trans filter for a horizontal plug, no plugs here..... removed the trans filter and a fair amount of gunk was in there, cleaned out the canister and re-fitted the filter ('cause i don't have a new one for it yet).

Now here's the interesting part--- there is no horizontal plug near the trans filter as described in other posts on this problem with other jd400s. there is however a horizontal fitting with hose attached that leads to another filter canister???? no one ever mentioned that there would be two filters!!! i didn't remove this second filter 'cause it is a huge sucker and i didn't want oil everywhere...

I climbed out from under the machine, started her up and checked the loader function.... MUCH faster!!!, still not fixed properly yet but she gets full travel in around 45 seconds, good enough to send a transporter to pick her up and bring her home.

Off to the deere dealer this week to order some new filters for her...... happy days!