hydaulics probs ....

tom lad · Post by **tom lad** » Tue Oct 05, 2010 9:54 pm

hello all

first post ! lol

questions .. issues with my s dexta ..

i,ve had a search on here for ideas ..

i have a internal leak on my hydaulics. arms drop from the rased persition un till system corrects , set in position control ,prob only 8 - 10 seconds between corrections, if i pull out the auxilary knob it stays up alot longer - prob 8 minutes with a 2 f plough, engine swiched off .
check valve leaking ?
how much damage on the check valve ball for it to leak ? mine does have rings on it , but very minor ??? the seat looks ok .. i think .
the main control valve, i think is ok , nice snug fit , the unloading valve seems fine .....

all systems had a, good clean , new seals return filter ect.

i have problems tryna get the qualicontol settings to .. my turn buckle wants to be longer to get the 10 mm setting and i honestly dont know why .
thanx in advance , tom

Post by **Brian** » Tue Oct 05, 2010 11:02 pm

Welcome to the board.

A correction rate of around six in a minute is a little high but not excessive and if it takes eight minutes to hit the floor with the engine off it is a little fast. But remember, it was never designed to hold up all day with the engine off. The much vaunted Fergy lift will hit the ground as the engine stops.

Check valve? Possible but do not go there unless forced. The seat may be damaged and they are no longer available as far as I know. The ball should have no flats or grooves on the surface.

Worn/damaged control valve? More likely especialy if it has been cleaned with wet/dry or emory at some time. New units are available but you will need the colours from the valve.

The unload valve will not be a factor.

If the lift drops with the aux service pulled out it must be piston seal or ram cylinder safety valve as all other valves are isolated from the circuit. Could be ram cylinder or aux service plate "O" rings.

Adjustment problems? Check your position control pin for wear. On a Dexta that is the most likely cause.

tom lad · Post by **tom lad** » Wed Oct 06, 2010 11:42 am

thanx brian

i have replaced the cam follower pin a while ago , it was well worn .sorry should have mentioned that .

when i removed the lift piston it had a lip type seal , agriline sold me the o ring and backer last year ... so that was in last time it ran .
now i,ve fitted a lip type from agriline , like the original one.
the cylinder is scratched but i,ve polished it best i can ( dont want to buy a new cylinder !) so the 8 minutes was with the o ring type in - so can only improve i hope

i have a new check valve ball on order mine is 11mm ? so thats 7 /16 i guess .(from my local bearing supplyer )

in draft its lifting slow because the valve isnt being pushed all the way in - works fine in position .
mine has the flow adjuster , so half and inch from the upper notch?
the disc thingy on the quadrant lever is broken off on mine , not sure what its for ?
mine held on with two bolts , my instruction book is for the four bolt type (earlyer model ?)

Post by **Brian** » Wed Oct 06, 2010 4:20 pm

You need the flow adjuster screwed right in to get a fast lift or make sure the rod link from the control lever is moving it into fast lift.

The "O" rings are for the '000nd series and do not seal a Dexta piston. You need the lipped seal.

The cork disc is an essential item otherwise you will not be able to hold the lift lever in any position for draft and position control to work.

You have the later lift cover.

tom lad · Post by **tom lad** » Thu Oct 07, 2010 5:11 pm

ello

the thing on the quadrant lever is on the lever its self , about half way down , i've photo'd it but i cant see how to attach photos.

have made new cork friction washer .

i've found now that if i loosen the lock nut on the internal qualicontrol override spring , by the swivel and guide unit i can now get the settings

, .... the book says this nut should be tight tho i think ,..
or cut the guide shorter - add a washer on the guide above the swivel .... ????? im reluctant to start butchering the linkage

my flow adjuster works screws in ok

the lift before was slow , wen set in draft , faster in position , this is because ( i think ? ) the valve isnt been pushed in very far, even when in full lift . but in position pushes all the way in .

am i missing some thing ??

seems odd that the ram con rod doesnt push square to the lift cover , lift arm ends in the center but the cylinder is ofset , room for the valves i guess.

thanx for advice brian

tom lad · Post by **tom lad** » Mon Oct 11, 2010 3:15 pm

another thing i dont understand is why does it matter were the lift arms are set to make the draft setting.
i understand that when in position control it is inportant because of the position of the cam , + cam following pin , i guess 10 mm setting is valve in hold - neutral position.
so i see how the cfp wearing will comfuse the system BUT

when mine is in draft setting the cam never touches the pin ( i have replaced the old worn pin last winter ) the closest it gets is about 4 mm away , the arms fully lowered .

none of my linkage looks bent - damaged to me but its the only dexta i've ever messed with . ( hope i dont sound like i'm ranting .... just strugglein )

i'd love to sort this one because i'm stuck

tom

tom lad · Post by **tom lad** » Wed Oct 20, 2010 5:44 pm

hi all

how do i test the control valve for ware ?
i'm saying it fine but are we talking thous ?

buy a new one from agriline ?

do the colours meen different diameters ? i wonder how much diameter difference between the different colour sizes

we can only change the valve its self and hope the guide is fine ?
from memory mine had a dark blue spot nr the valve

bin ploughing last week with a 3 furrow plough

pulling it quite happly .