1640 back end problems

[Mike nelson]

Hi all my problem is hydraulics on there own all work fine
arms lift good plenty of power
steering smooth (1 finger )
hydraulics work fine also ( pumps/tipper/rams )
the problem is when I use them together if I lift my 350lt sprayer to the working height as soon as I engage the hydraulic pump (to spray) the arms lower also the steering affects the arms just an inch or so
its had new filter, the screen cleaned (bye the way was very clogged),and the screen in the high pressure pump cleaned have all so had the pressure relief valve out was clean but didn’t test operation
finally new oil
hope someone can help as local john Deere dealers could not help thanks from the uk

 

[JimB77]

Welcome to TBN
It would help tremendously to receive correct answers to your tractor problems to reveal the manufacturer(brand) of your tractor which I'll guess must be a John Deere 1640. If 3 pt lowers from operation of other hyd control valve then the rockshaft internal control valves which have a very long history of failure or rockshaft piston seals are leaking. With engine operating at 90°C, 3pt raised look inside hyd filler hole for spraying oil which will be caused by leaking seals. In order to replace these faulty seals one needs to R&R rockshaft housing that contains mechanism that raises 3 pt hitch. Another less likely possibility is that the rockshaft control valve clearances are set too tight. To check those clearances you need to acquire a tech manual for your tractor model.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/76165/referrer/navigation/pgId/147864363

 

[Mike nelson]

Thanks Jim your right it is a john Deere 1640
i guess that means cab of and a fair bit of dismantling so whilst that lot goes on is there a more in depth rebuild kit ?

 

[JimB77]

AL57974 contains gasket & numerous seals for rockshaft control components. What more in depth are you referring to? yes cab will require removal or at the very least raising up.

 

[Mike nelson]

Just any items that wear out mite as well be done whilst stripped down

 

[JimB77]

Rockshaft piston seal should be replaced when rockshaft housing is removed from tractor. Later model 1640(> sn 430000) lists 2 different diameter for RS pistons(92MM & 100MM)

 

[Mike nelson]

Hi Jim is sn430000 a good number can’t get any results?

 

[JimB77]

What is the last 6 digits(numbers) of your tractor serial #? If you don't feel comfortable exposing your tractors serial on the internet then insert XXX's for last 3 digits.

 

[Mike nelson]

I shall do that tomorrow Jim

 

[Mike nelson]

Hi Jim can we take up my 1640 problem again please will get numbers tomorrow thanks Mike