Volvo EC150 hydraulic problems - or not?

[richmondfarms]

I come seeking knowledge I've owned a couple of excavators in the past......way in the past. I had a Bantam C-166 with a 4-53 Detroit and have also owned a Bobcat mini. Recently I scrounged up an" auction queen" to keep here on the farm, it is a 2001 EC150-LC, Cummins engine, 8800 hrs. Not too beat up but could use some TLC. Hopefully you guys can point me in the right direction for getting her up and digging. I'm fairly proficient as a mechanic, but the only electrical system my old Bantam had was the starter and this Volvo thing seems to have a few more wires. The left track will spin it around on flat dirt, but the right track is weak. The boom and bucket weak and slow as well. Stick is fast and seems powerful. This thing has some kind of tandem pump setup from the looks of it, so I am guessing also that it has two main relief valves? Never makes any black smoke, engine doesn't load up. Dead head on the stick you can hear the engine work harder. I have no history on the machine and I have found a service manual and a a parts manual on ebay, should be here soon. I won't dump it back into an auction without disclosing any possible problems, so I'm in it to fix it and dig.

 

[uffex]

Good day
The 150 you describe with a Cummins sounds a lot like Samsung could you post a picture and we will try to help you.
Kind Regards
Uffex

 

[richmondfarms]

It kinda looks like some of the Samsungs also - plus it is made in Korea. I'll get you a picture of her.....

 

[uffex]

Good day Richmond
See attached we suspect this may be what you have.
Kind regards
Uffex

 

[funwithfuel]

It is truly a Samsung in Volvo clothing. That said, boom , bucket and right travel are all weak? Those are all off pump 2, the outboard pump. Figure your left stick and travel are on pump 1 the inboard pump, your right stick and travel are pump 2 the outer one. It sounds like your pump controller is weak or inactive . I would normally point you towards the filtered inlet fitting at your right joystick, however that wouldn't knock down your travel. So, that points more towards your pump controller. A simple test would be to swap the magnets/coils.
You said you can hear the engine load up on pump 1 but pump 2 doesn't load at all. That would be because the pump is in Q-min or minimum displacement .

 

[funwithfuel]

See if when you are travelling right side and pull arm in, does your track speed increase

 

[richmondfarms]

Good day Richmond
See attached we suspect this may be what you have.
Kind regards
Uffex

Looks very similar, even has the same aux remotes.

My machine is:

https://www.proxibid.com/aspr/2001-...1230217/LotDetail.asp?lid=41230217&rfpb=0#Top

 

[richmondfarms]

I'll spend some time with it tomorrow. It does behave as if one entire side is weak, the entire right side. I have some mechanical background, in a previous life I was a M-B dealership tech and ended my mechanic career as a shop foreman for 10 years, I do have a shop with a lift and a bunch of worn-out tools. I try to stay current and also work on my wife's old 986 boxster. I have some hydraulic test gauges with quick couplers on them but I have not seen them for several years, will try to find them. My hat is off to you guys who work on these machines for a living, much appreciated.

 

[funwithfuel]

The test fittings at the pump should be stauff 1.5, the new standard is stauff 2.0 you don't want to force one on the other. It might be best to just get new test fittings that match your test equipment. BTW pressures may reach up to 4500psi , gauge accordingly.

 

[Vetech63]

It is truly a Samsung in Volvo clothing. That said, boom , bucket and right travel are all weak? Those are all off pump 2, the outboard pump. Figure your left stick and travel are on pump 1 the inboard pump, your right stick and travel are pump 2 the outer one. It sounds like your pump controller is weak or inactive . I would normally point you towards the filtered inlet fitting at your right joystick, however that wouldn't knock down your travel. So, that points more towards your pump controller. A simple test would be to swap the magnets/coils.
You said you can hear the engine load up on pump 1 but pump 2 doesn't load at all. That would be because the pump is in Q-min or minimum displacement .

Ive even swapped the electrical plug in before between the 2 pump controllers.

 

[funwithfuel]

Not the plugs, the controller coil itself. But as I reread your post, this may not be up your alley, yet... swapping a controller is a little involved and requires you to open the pump a little. This is something you would want to do as benchwork anyway as the controllers are on the side iirc.
Now, since you are a MB tech, I'm sure you have experience with pwm coils. You'll want to actively measure mA to the 2 controllers. The easiest way to do this is to swing the house perpendicular to the carriage. Raise one track of the ground. Place a 2 maybe 2 1/2" pin between the sprocket and car body. Slowly run track till pin is bound between sprocket and frame. Now pour the coals to it and travel against pin. That will be maximum load against that pin for that pump. So that's the point you want to measure mA . Do this for both sides, compare. If results are close , probably no electrical influence. It would be better if you could gauge pressure and read mA but I don't know how you're equipped.

 

[richmondfarms]

See if when you are travelling right side and pull arm in, does your track speed increase

Yes.

Also may add that boom "down" barely lifts the machine 6-8 inches off the ground and then just sits there quietly, but boom "up" all the way is pretty damn fast and when it dead-heads the engine lugs some and you can hear the relief valve working

Bucket is slow/weak both directions, no load at ends of travel..

Working on the rest of my assignment, I have un-pinned the connectors on the pump control pwm solenoids and found my DVOM. I am familiar with the 4-20 mA feedback loop circuit. No luck finding my hydraulic test gauges, still looking. Most switches and instruments seem to work, the rpm display on the left console looks like it was beat with a hammer, but the first two letters are ER-(not legible), so maybe the machine is trying to tell me something. Guess I need to fix that too. Also I fear that there is some required family time approaching, so might not be back on this today........

Happy Easter!

 

[funwithfuel]

100% behind you on the holiday. At least now we know the problem is pretty well localized to pump/controller area. Arm in, in full stroke uses both pumps same as boom up for speed. The fact that travel speed increased means that the MCV is shifting oil and driving spools as it should.
Gotta get some gauges going. Also ER is the predecessor to a 2 digit fault code. There should be some characters lit up as well. A crankcase, 2 connectorsfacing each other, and another. Those indicate where the fault lies, the number indicates the fault. Think of it like OBD I back in the 80's

 

[richmondfarms]

Ok, got my first homework assignment done and have a report ready..... First off, I did swap the pump control solenoids, nothing changed (the inboard pump solenoid is mounted remote, but they look the same, connectors are different but I had unpinned them anyway). Testing the feedback loop was interesting, outboard pump around 1.8 to 2 mA at idle or under load, no change. Inboard pump solenoid 0 mA, 0 volts nothing, zip, nada.

I will add that the machine acts the same when both solenoids are plugged in or unplugged, left side seems strong, right side weak/slow. Since I have no history, I would not rule out a combination of problems, or perhaps some problems caused by less-than-knowledgeable persons. The display shows ER-(three horizontal bars, so it could be a 3, 5, 6 or 8 I suppose. I was going to call and get a price on the display today but ran out of time.

 

[funwithfuel]

Well, there ya go. No mA no flow. The hunt is on, gotta find where that circuit is failed. You said previously, you have manuals coming? You're going to be very familiar before to long.
Good luck, glad to hear the pump is not the likely culprit.

 

[richmondfarms]

Well, I was just looking around at some other information on here and realized that I never reported back on the Volvo. I found a shorted wire where the main harness was rubbing the head of a bolt as it passed over the top of the flywheel housing. Naturally the shorted wire melted and blended in with a few friends. Stripped out the harness and repaired it, machine was different and still no dig, but hey, got the fuel cut solenoid working. Kept looking for problems and decided to test bench the pump just for s&g’s, pump was not only good, but I got “this pump seems almost new” from the test shop. Hmph, well that’s nice. When I pulled the pump the coupler fell out in crumbs, but was covered in gorilla glue. New coupler and reinstalled, still no pressure from outboard half but the inboard half was great and pilot pump was great. Finally made sense of the hydro schematics and figured out two pilot control hoses on the outboard pump controller were reversed. I had marked everything when I pulled the pump and put it back just like the previous owners had it prior to dumping it in the auction. I guess the pump coupler Grenaded so somebody glued it back together (literally) and sent the machine to auction, but screwed up the hose placement on the outboard pump controller in the process. Cost themselves some money though, I bought the machine for 18k. Back in business, the old 150 Samvo is actually an awesome farm excavator, it digs like a b*****d and is super smooth and fast. Anyway fast forward to now and it is still doing great, thank you to all who helped get me going in the right direction!