weak swing on volvo ec240c

[VOLVO GUY]

Hi can somebody help me!my 2008 volvo ec240c excavator has weak swing left and right,when I lift the the stick at the same time the swing starts workig normanly.everything else seems to work well.

 

[uffex]

Good day Volvo Guy
I will try to help you but I need some answers, - first the same pump provides oil for both stick and swing, by operation of the stick is blocking one passage to tank. Please come back to me and tell me is the crawlers operate OK on bucketsense@gmail.com
Kind regards
Uffex

 

[VOLVO GUY]

Hi
thanks for responding, everything on my machine seems to work fine except the swing is just one speed, slow, and weak. when I use different functions like lifting the stick it works fine. slew brake works fine to. Any suggestions would be greatly appreciated.
Thanks

 

[DirectTech]

It sounds to me like the signal is not stroking the pump up, but when you use the stick or some other function it my stroke it, you might what to tee a gauge into the control line on the pump and see if when you activate the swing if the pressure drop which it should if it does not then you could have a problem in the MCV..

 

[uffex]

Good day Volvo Guy
I have checked the circuit and from your description we suspect a fault of a check valve behind an allen plug tank side adjacent to pump inlet. Lets check it out - the following install a couple of gauges to the pump test points stall the bucket see if the pressure is good - next same thing with bucket in the ground operate the swing -next stall the arm you shoud see pressure on both pumps. Come back with the results.
Kind regards
Uffex

 

[VOLVO GUY]

Okay,I will have to run for pressure gauge, Im not a machanic by trade so be patient with me, I just want to fix as much of my own equipment as I can,if you could let me know exactly what you need that would be very helpfull.
Thanks Much

 

[uffex]

Good day Volvo guy
Here is what we guess is the problem, if the attached is not so clear come back to us at bucketsense@gmail.com
Kind regards
Uffex

 

[VOLVO GUY]

Can you tell exactly me where this check valve is located
I ran some tests , I'll call pump 1 the pump that is closer to motor
when:
tilting bucket: pump 1- 800 psi pump- 2 3800 psi
lifting stick: pump 1- 800 psi, pump- 2 3500 psi
when slewing left: pump 1- 900 psi, pump- 2 600 psi
really appreciate this!

 

[uffex]

Good day Volvo guy
We must work some to get a good illustration so just bear with us we will get you the info you need, if you have a direct email address please post it to bucketsense@gmail.com this will make direct communication much easier.
Kind regards
Uffex

 

[VOLVO GUY]

Hi Uffex, I sent you 2 emails already to bucketsense@gmail.com didn't you get them?

 

[uffex]

Good day Volvo guy
No they did not appear send a email to uffex@aim.com we will try another connection, we are still working with a illustration for you.
Kind regards
Uffex

 

[billythebairn]

Hi, i dont know if youre canada spec m/c is the same as uk m/c, if it is and i expect so then all functions are controlled by vehicle ecu which recieves a signal from press sensor in servo line, when lever is moved this in turn sends signal to ecu and ecu tells hyd pump to stroke up and supply flow as req. do u know if u can check your hyd press in service mode on dash? if so select this and u can see servo press reading which should be approx 40 bar on full deflection of lever, also is there any error codes on dash?

 

[VOLVO GUY]

Hi, I can get into service mode but I don't see a servo pressure reading, there is a pressure option called- pressure switch swing, I cant start the machine now, Its apart. I will put it back together tomorrow and see what reading I get.
I will also try to upload a picture of the dash so you can have a look at the options on the menu.

 

[VOLVO GUY]

also no error codes on dash

 

[VOLVO GUY]

Hi Uffex, I sent you another email, if you didn't get it you can email me at silverlevel@hotmail.com

 

[billythebairn]

Hi, it looks as if u r running our type dash but with older B style hyd sys as on hyd menu page we have press sensor link which shows main pump press and servo press readings for all sys components, the 3rd picture u show is i belive is only for auto idle it will be 0 when not in use and 1 when activated.

 

[VOLVO GUY]

Hi Billy, I think you are right, I got my machine running and when I press the foot switch the travel port press goes to 1,same thing with other functions, But when I swing the swing menu stays at 0. Any thoughts?

 

[billythebairn]

Hi, does the auto idle work when you swing? as this worked by a press switch activated by servo press when you move lever, revs should pick up when o/k

 

[VOLVO GUY]

mmm...just checked autu idle doesn't work at all this machine, faulty sensor maybe? I did turn on the auti idle switch.

 

[billythebairn]

yes probably, have u got any pressure readings from pump when working swing, u should have approx 200bar with bkt firmly on ground ie stall, and if not is the press ok on other circuits approx 350 bar on end stroke?