# 3350A front loader hydraulics help please!



## droljko (8 mo ago)

Greetings from Croatia. My first post!!!
I usually do hydraulics for excavators, but rarely I do work on tractros as well, if I can't wiggle my way out of it 
Friend has 3350A with front loader and wants to upgrade the distributor as original one is leaking and he wants to change the position of it. I've never worked on Deere 3350A.
I had a look at the existing system and I can't figure out few things. Existing distributor is located on the right hand site of the seat, and apart from hoses going from 2 valves to the cylinders, it has 2 hard pipes and one flexible hose coming to the block. Flexible hose is coming from the either a small pump or regulator mounted at the bottom right hand side of the trancmission housing, so that must be supply. One hard pipe is going to the hydraulic filter, and another is going in the housing under the seat. Both hard pipes have rubber piece of hose that is tightened just with screw type clamps, so they have to be return or very low pressure. The one going back to filter is return obviously, but I don't know what the one going under the seat is for?
Can anyone please help me with this?

Many thanks!!!!


----------



## Tx Jim (Jul 28, 2020)

Welcome to the TF
I have no experience with model 3350 but nearly all JD tractors of that era are similar. Do you know these models have closed-center hyd's & are you familiar with how this hyd system should operate. I think parts photo below is the type hyd's you're referring. If I'm correct hose(item 2) is pressure supply, Hose(item 12) is unpressurized oil return to hyd oil reservoir & hose(item 21) is low pressure return through spin-on filter.

From reading your post if I'm understanding you correctly it sounds as you understand the hose routing correctly.

Any hyd control valve(distributor) you add to tractor hyd system must be compatible to a ""closed-center system"". For faster loader response I recommend routing hyd control valve(distributor) return oil to ported hyd filter cover under RH side of trans case. If ported filter cover isn't already on this tractor one can be purchased from JD. Ported hyd filter cover part # is L55982
2nd photo depicts how JD engineers thought FEL control valve should be attached to tractor hyd system.

*Attachments*


----------

