I have a volvo ec240c that is a nightmare. Had problems the control valve. One of the poppet seats for boom was beat out of the control valve. Changed entire control valve. One of the problems I was having before that is the right track is slower than left track until you select any other function beside bucket curl. When you select another function track speed increases to normal. Right track is on p2. I swapped hydraulic output lines on top of the pumps. P1 and p2. The problem went to the left track. Before swapping I checked all pressure. P1 and p2 over relief on boom, track, swing, arm. All pressure are in spec. Checked pilot pressure are all in spec. Checked milliamp are all in spec. Seems a flow problem with p2 but wanted advice being I had to drop 18 grand on new control valve. But swapping lines like I did should eliminate everything else besides flow problem on p2???? Please help. Thanks
It seems you have a flow problem. You will need to get into service mode on your display. You need to check all your inputs against rest / neutral and against full throttle/ full load. For example if your sensor for travel is giving a false high value , your pump will be destroked. But, you pull another function, that sensor says, I can use more oil, you stay stroked. Have you measured case drain off the weak side? Does your machine have straight line travel pedal ? Have you inspected the case drain filter?
I have checked over relief pressure on all functions. Seems to be in spec. Checked pilot pressure are in spec. The travel pressure switch I believe is just like a on off switch. You can put machine in auto idle and it will idle up on all functions. The only thing that gets me is when I swapped p1 and p2 lines the slow track went to the other side. Any other suggestion? Didnt check case drain flow yet. Bucket curl is also slow
Machine does have straight travel. Right track is slower in straight track as well. Any help would greatly be appreciated. Thanks
That makes perfect sense. R/Travel and bucket are on same pump. I'm speculating an obstruction in the pump regulator or the LS line to the pump.
You mean the compensator? I took it off and cleaned it. Did find the plunger for servo was hung up. Polished and cleaned it and put new o ring. Same problem. I even swapped compensator for pump to pump. Same problem. You say ls line. You mean the line going to compensator??
From the MCV you should have 2 LS or load sensing lines going to the compensators. One bank feeds one pump and so on. Gotta T into LS lines going to pump. Compare 1 against 2 . When you pull additional function, you're using the center passage which combines both pumps. 1 pump at 100% and one at 30% might feel like a lot but still be lacking. I'm guessing there's an orifice or filtered fitting gumming up the works.
Let's raise one track and time 3 revs at high speed in full throttle. Then do the same test on the other side. This is important. The fact that the bucket circuit is suffering as well indicates that it's more an MCV problem than a turning joint issue.
I t into low side lines. at high idle. P1 546. P2 516. Bucket over relief 48.
When curling bucket you can select any other function and it will not speed up. When I swapped pump lines the other day bucket was normal
That doesn't make sense, you have a positive control machine, not negative. Check pilot pressure under cab floor where it splits off going to foot pedals and joysticks. There are filtered fittings at each consumer. Sometimes trash gets jammed up in there.
Check pilot oil pressure going to RCVs Check pilot oil pressure going to MCV spool caps. Circling back to the beginning, case drain filter will tell us a lot. You could also remove and inspect the main hydraulic return filter in the tank well, see if you have captured debris.
Makes sense, you were running off another pump.
Right track 3 revolution high idle 47:48. Left track 19:46.
All filters are clean.
I'll look at schematics and diagrams this evening. I'm sure Paul C will be along soon to share some as well. There's quite a few of us that speak Volvo here.
Thank yall.
Trying to locate the screen fittings now.
Are they right under foot control or little further back?
I dont know if it would be screens being the problem went to the other side when I swapped hoses. But if I can locate them I'll definitely check it out.
Don't confuse pressure with flow. 2 totally different things. Looking at diagrams and descriptions now. Will advise when I have solid info.
here , take a look at the schematic and pump description. The schematic has been noted . The pump descrition will show you where you need to t into the line to check in your post 9 I believe you were already in there. We need to see the drop off with the track speed test again. We wanna see that P1 and P2 are each dropping off as they should when the demand is greater. The tracks are the simplest way of measuring flow.
Hooked up to lines on compensator. High idle p1 560. P2 480. Tracking forward both drop to around 50 but left track faster. If you back off of left track to make it track straight p1 goes to 320. P2 still 50. You wanted me to check case drain after case filter going to reservoir?? Just curious is this checking that a valve is stuck letting bleed off to tank? Still hung up about when I swapped lines on pump. Is that meaning definitely pump issues?? Or just something not letting pump come online?
Switching pump 1 & 2 discharge lines, you still had the same oil coming into the MCV the center passage opened up and allowed extra oil come in and do work. So for example pump 1 would have been at min displacement, pump 2 stroked up and did the work of 1 . Does this make sense? It sounds like your MCV is ok and doing its job. I'm leaning towards the fault being in the pump, mainly the controller. There has to be an obstruction keeping that pump destroked. There could be a bind in the piston as well. You mentioned that you had already been in there.
Yes. When I swapped compensators. Is it possible to take compensator off of p2 and move it some how or something to see if its stuck.
I'm just grasping at straws
Move piston I mean
Aside from swapping controllers and exercising spool within, I've not messed any deeper. In my part of the world, once we had narrowed it down to the pump or a valve, you replaced the component. Labor costs are higher than reman costs and come with sweet warranties vs no warranty. Hopefully someone will step up with intimate knowledge of the guts.
The comp should fit onto a pin. You should be able exercise the pin or yoke that the controller acts on, there should only be spring tension
Ok thank yall for all yall help.
I am asking for the hydraulic schematic diagram of this volvo Ec240c
Please open a new thread with your request. Make sure to post your serial number and what options you have installed. If possible mention whether the options are factory or aftermarket. Thanks.