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Welcome lovers of skinned knuckles and contortionists
Ive posted about this problem before but have some pics of the parts for you this time..gif "thumbs up")
Take the time to have a look because this problem affects many excavators across all manufacturers that use pilot controls, and what looks like a nightmare , is a very simple problem.Often you are greeted by seeing the digger with a service 'stuck' on, a ram at full reach and the engine 'labouring', or it wont start with a ram at full or retracted reach, because the engine is loaded by its hydraulics at full relief. It seems as if the battery is dead, but its just, that the starter cant crank it fast enough due to the pump being fully loaded.
The problem is a service being stuck 'on'. Normally thats a straight valve block problem , but not always as in this case, as I always say .. keep an open mind and look for the simple things first.
The give away with this problem is a flappy control joystick here you can see the stick 'B' has fallen forward onto the depressed pilot 'A' which will not pop right up
Img_1624.jpg
So on this one .. that will throw the dipper straight out .. all by its self .. not good
So its time to remove the whole left hand pilot which is usually four fixing bolts and all the hydraulic feeds underneath .. (usually 6 lines)
Img_1625.jpg
Here you can see the problem pilot still stuck down
But it should be easy from here on in the brass plug holding the pilot on this Rexroth unit just pops out with a little twisting with some pliers
IMG_1626.jpg
Watch the plastic valve set underneath doesnt spring out though .. it normally pops up but stays in the block
Next you need to split the pilot .. it should just pull/push out FROM THE BOTTOM but it will be stiff remember .. thats why we have the problem in the first place
Img_1635.jpg
Its possible that a tiny retaining ring on the bottom is what causes the problem .. possibly belling the end of the brass pilot through constant pounding .. and it would only need to be by a tiny amount to cause it to lock
Img_1633.jpg
Now you need to get some emery paper into the brass bush to rub/open it out again .. start with 120 grit .. then use finer stuff to finish .. watch the o ring on the INSIDE up at the top .. or take it out if you are nervous !!!
Img_1637.jpg
Then its a just a clean out with some rag .. lightly oil and reassemble
IMG_1639.jpg
And there we have it .. fire up the engine .. drop the console to get the pressure back up in the pilots, and the lever will sit level again !
Job done .. another couple of hundred beer vouchers saved people :wub:
and for Volvo EC owners its about an hour and a halfs work
Ive posted about this problem before but have some pics of the parts for you this time.
Take the time to have a look because this problem affects many excavators across all manufacturers that use pilot controls, and what looks like a nightmare , is a very simple problem.Often you are greeted by seeing the digger with a service 'stuck' on, a ram at full reach and the engine 'labouring', or it wont start with a ram at full or retracted reach, because the engine is loaded by its hydraulics at full relief. It seems as if the battery is dead, but its just, that the starter cant crank it fast enough due to the pump being fully loaded.
The problem is a service being stuck 'on'. Normally thats a straight valve block problem , but not always as in this case, as I always say .. keep an open mind and look for the simple things first.
The give away with this problem is a flappy control joystick here you can see the stick 'B' has fallen forward onto the depressed pilot 'A' which will not pop right up
Img_1624.jpg
So on this one .. that will throw the dipper straight out .. all by its self .. not good
So its time to remove the whole left hand pilot which is usually four fixing bolts and all the hydraulic feeds underneath .. (usually 6 lines)
Img_1625.jpg
Here you can see the problem pilot still stuck down
But it should be easy from here on in
the brass plug holding the pilot on this Rexroth unit just pops out with a little twisting with some pliers IMG_1626.jpg
Watch the plastic valve set underneath doesnt spring out though .. it normally pops up but stays in the block
Next you need to split the pilot .. it should just pull/push out FROM THE BOTTOM but it will be stiff remember .. thats why we have the problem in the first place
Img_1635.jpg
Its possible that a tiny retaining ring on the bottom is what causes the problem .. possibly belling the end of the brass pilot through constant pounding .. and it would only need to be by a tiny amount to cause it to lock
Img_1633.jpg
Now you need to get some emery paper into the brass bush to rub/open it out again .. start with 120 grit .. then use finer stuff to finish .. watch the o ring on the INSIDE up at the top .. or take it out if you are nervous !!!
Img_1637.jpg
Then its a just a clean out with some rag .. lightly oil and reassemble
IMG_1639.jpg
And there we have it .. fire up the engine .. drop the console to get the pressure back up in the pilots, and the lever will sit level again !
Job done .. another couple of hundred beer vouchers saved people :wub:
and for Volvo EC owners its about an hour and a halfs work
.gif "thumbs up")
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