Champion superpac 840

[chris_james]

I have an superpac 840 that will not move. It will turn it will vibrate. Another mechanic rebuilt the propel pump. After we hooked everything back up the problem continued so we replaced the brake solenoid which was bad problem still there. So does anyone have anymore ideas of what it could be?

 

[chris_james]

I take it noone has any ideas on this one?

 

[BillG]

Never worked on one but I have worked on many hydro systems. What type controls, mechanical, pilot, servo mechanical mix? Have you checked any pressures? Does it have a neutral lock? Any pictures of the pump and controls would help.

 

[lantraxco]

Gotta love Minnpar:

http://www.minnpar.com/partbooks/SuperPac/840-840p Parts PN L-3022 effective sn100306.pdf

What happened when it stopped working? Was the drive pump tested after rebuild? Was there a failure in the pump that might have contaminated the system? What are you getting for charge pressure, in neutral and when activating the drive? Do you hear any noises when you try to move?

My first guess if you had a sudden failure without metal everywhere inside would be one of the multifunction valve cartridges in the 90 series drive pump has come apart inside.

 

[chris_james]

It was a sudden stop just going along then it stopped moving all at once. Im am getting 0psi from the propel pump, 0 psi from the foward propel and reverse and 100pis from the charge pump. The controls are manual. And no strange sounds.

 

[lantraxco]

First off, I don't know the specs on that machine, but 100 psi sounds way low for a 90 series pump which is what I'm guessing that is from the parts pictures. Danfoss says 260 psi minimum and they're usually set at like 340? You either have a bad charge pump, charge relief, or a large bypass to tank somewhere that's not letting the charge pressure come up. If you can get the model number code complete off the pump or post a picture of the tag we should be able to figure out what the pump was set for when it left the Danfoss factory at least.

I would start by disconnecting and capping the line from the pump to the brake and two speed solenoid valves, check charge pressure again just to eliminate that part of the circuit. If there's no change, disconnect and cap the two high pressure lines going to the "loopflush valve assembly" which is supposed to dump hot oil out of the low pressure side of the loop when travelling, it's another place where oil can bypass back to tank. These lines have full travel pressure on them so take appropriate precautions. Check charge pressure again, if the charge pressure comes up, the loopflush valve needs resealed or new cartridges maybe, if there's still no change your problem is either internal to the pump, or one of the three drive motors. Charge relief in the pump would be the next thing to look at I think.

 

[chris_james]

Yeah the charge pump should be at 350 ill have to check again tomorrow. On the two speed solenoid. Ive check it pulled it out and put a jumper wire to it its working. Not sure if that makes a difference about caping off the line to it. All the psi should be as follows propel pump 500 charge 350 foward propel 1800 same with reverse. I will try out your advice tomorrow as well as info from the data plate on the pump

 

[lantraxco]

As far as capping lines, just looking for places you could be losing charge oil back to tank. The two speed shift and brake release both work off the charge pressure. The lines are probably too small to allow much flow even if there's an internal malfunction but it's worth checking.

I don't get the propel pump at 500 psi reading, is that supposed to be in neutral or? 1,800 seems real low to me, but then I haven't worked on one of these, usually skid steer or track drive hydrostats.

 

[chris_james]

Ok with the book in my hand the propel pump needs 500psi, charge pump needs 500psi, f/r propel needs 1000psi. For the test prots.

 

[chris_james]

Ok with the book in my hand the propel pump needs 500psi, charge pump needs 500psi, f/r propel needs 1000psi. For the test prots. Also on the loopflush where would you cap the line

 

[lantraxco]

That kinda makes sense since the propel pump should be seeing charge pressure in neutral. I can't believe this thing moves with only 1,000 psi, see something new every day!

Should be two smaller lines on the loopflush block, like #6? Remove and cap those. The third line is the low pressure return.

So, was the pump tested on a test bench after repair or?

 

[chris_james]

No it was not. We rebuilt it in house. And don't have the test equipment. Ok on the loopflush it has 6 lines on top the right side has two which is the propel side the left best I can tell vibrator side has 4. So cap the top two lines on the propel side and the top of the loop.I took pictures just can't seem to post them from my phone

 

[lantraxco]

If you're in doubt at all those two lines come off the drive pump main ports, there should be tees on the pump where these and the guage port lines take off as well. Only need to cap those two lines for this test.

If nothing changes during these tests, may have to block off the main pump lines and check charge pressure again.

 

[chris_james]

Ok thats them then yeah its teed two lines run to the toop other run to the test manifold. Lol im just so tired at looking at this packer its making my head hurt

 

[lantraxco]

Been there done that, feel yer pain.... :Banghead

As a wise old marine repair dude once told me about a troublesome tugboat in dry dock: "Relax, they all sail"

 

[chris_james]

Tried both today. Still thensame no propel pressure and 100psi on charge. Serial number on the main pump is 90R100md1b6r3f and either a 6 or a g can't tell. Model # 9621570-A96-15-23831

 

[lantraxco]

I was afraid that might be the case. Must be an OEM special pump too, the model code isn't really telling me much, except it is a 90 series, right hand rotation and 100cc per rev.

Next thing I would suggest it to grab some #16 caps and plugs, disconnect the drive hoses at the traction control valves and cap everything off. I like to leave some hose attached to the pump ports, just gives it a bit of dampening if you will because you're deadheading the pressure lines. Just start it up in neutral and look at the charge pressure, if it doesn't come up with the main pressure lines capped off, the problem is in the drive pump/integral charge pump.

If the charge pressure does come up to snuff at this point, gingerly try the propel and see what you get. Should be perfectly safe but this always makes me nervous with the lines capped off so I like to ease into it. The multifunction valves in the pump will destroke the pump if you do get pressure and if you get a spike they also act as reliefs. If everything comes up to book spec with the lines capped, then you'll need to figure out which motor is bypassing internally but that should be just a process of elimination at that point.

By the way, you guys did fill the pump case with oil before starting, or bleed the air out until it was full if the tank floods it? Have to ask, I forgot once, wasn't pretty.

 

[chris_james]

To be honest im not sure about the tank. I didn't have lead on this project. The guy that rebuild the pump im sure put oil in the pump.

 

[chris_james]

Its looking like it was valve in the traction control. Haven't got it back together awaiting parts. Thats what happens when you have a piece of equipment with out a dealer in the state.

 

[lantraxco]

Well, making progress at least.

I don't see how the traction control valve could cause a loss of charge pressure, but with these hydrostat systems almost nothing surprises me anymore!

Let us know how it goes