Case 1825 charge pressure issues?

[skidsteer.ca]

My buddy's 1825 diesel get weak as the oil warm up. problem affects the drives on both sides, when pushing to fill the bucket the sticks shake and the charge pressure lite comes on, has a new filter.
Does anyone know where the valve that regulates the charge pressure is on these and any idea what it should be?
Looking for a down loadable manual, has anyone seen one for this model?
Any idea if it shares components with other models?

Ken

 

[Tazza]

Ken - i think it could just be wear on the brass wear plates and rotating groups. My 743 does this when warm and i drop the lift arms quickly. It will also do it if i leave the park brake off on a hill when shut down, the machine will creep a bit then i start it and it will growl and levers will shake, only for a second or so. The charge pressure light will flash too.
So thats my best guess

 

[skidsteer.ca]

Ken - i think it could just be wear on the brass wear plates and rotating groups. My 743 does this when warm and i drop the lift arms quickly. It will also do it if i leave the park brake off on a hill when shut down, the machine will creep a bit then i start it and it will growl and levers will shake, only for a second or so. The charge pressure light will flash too.
So thats my best guess

Well it not looking good. Hooked in the charge pressure guage and it hangs steady around 150 psi until you begin to push (forward or reverse , left side right side is all the same) It will spin the tires when its cold, but by the time the pumps were 120 f on the outside (infered reading) its get to where it won't spin.
With the tires stalled against a pile of dirt the hard you push the levers makes no difference, wheels are still stalled, but the charge pressure gets lower and lower the more lever you give it. The motor works some, but only when you give it 1/2 or more on the steering levers.
It does not really chatter until the pressure drops to 20 psi or so, above that its smooth, just not much power, I'm now guessing check the case drain flow and the pressure from the hydrostats.
Time to call LPS I guess
Ken

 

[Tazza]

Well it not looking good. Hooked in the charge pressure guage and it hangs steady around 150 psi until you begin to push (forward or reverse , left side right side is all the same) It will spin the tires when its cold, but by the time the pumps were 120 f on the outside (infered reading) its get to where it won't spin.
With the tires stalled against a pile of dirt the hard you push the levers makes no difference, wheels are still stalled, but the charge pressure gets lower and lower the more lever you give it. The motor works some, but only when you give it 1/2 or more on the steering levers.
It does not really chatter until the pressure drops to 20 psi or so, above that its smooth, just not much power, I'm now guessing check the case drain flow and the pressure from the hydrostats.
Time to call LPS I guess
Ken

Ken - got your e-mail. Before ordering parts I'd have a look at the condition of the wear plates and rotating group faces. If worn, thats your problem. The oil that should be going the the motors actually by-passes and goes into the pump housing instead of the motors. The charge pump then needs to replenish this fluid, this sounds like where your oil is going, and not your case drain line.
You can repair mild wear, but if the scoring is really bad, you will need new wear plates and rotating groups.

 

[skidsteer.ca]

Ken - got your e-mail. Before ordering parts I'd have a look at the condition of the wear plates and rotating group faces. If worn, thats your problem. The oil that should be going the the motors actually by-passes and goes into the pump housing instead of the motors. The charge pump then needs to replenish this fluid, this sounds like where your oil is going, and not your case drain line.
You can repair mild wear, but if the scoring is really bad, you will need new wear plates and rotating groups.

That sounds like what is happening. Being the pump appears to have been out once b4 in 1200 hours I'm temped to pull it down, might not be too bad.
Ken

 

[Tazza]

That sounds like what is happening. Being the pump appears to have been out once b4 in 1200 hours I'm temped to pull it down, might not be too bad.
Ken

Ken - the internals of the pump is very simple. I can send you a few piccies if you want a better idea of whats inside.
This i believe will be your problem, note the wear marks:

 

[skidsteer.ca]

Ken - the internals of the pump is very simple. I can send you a few piccies if you want a better idea of whats inside.
This i believe will be your problem, note the wear marks:

Tazza
Please do send the pics. Hi res ones.
You just resurfaced the brass plates?
They can't be too expensive to buy new?, it the rotating groups that $$$$$$
Going buy the parts break down they look similar.
Had someone else say the worst part is the high pressure reliefs seat into the center port casting, if the seats are bad it needs special machine work to repair. Generally the forward relief get worse then the reverse ones, so I'm hoping that is not the trouble here.
Ken

 

[Tazza]

Tazza
Please do send the pics. Hi res ones.
You just resurfaced the brass plates?
They can't be too expensive to buy new?, it the rotating groups that $$$$$$
Going buy the parts break down they look similar.
Had someone else say the worst part is the high pressure reliefs seat into the center port casting, if the seats are bad it needs special machine work to repair. Generally the forward relief get worse then the reverse ones, so I'm hoping that is not the trouble here.
Ken

Ken - with those hours i seriously doubt there is a problem with the relief valve seats.
I'll send the pics when i get home, can you flick me an e-mail to remind me too?
Yeah, those plates aren't too expensive, about 100 bucks, 500 from my local dealer! the rotating groups aren't that expensive either. The last set i needed i paid under $500 USD each for. You can repair the plates with sandpaper and a sheet of glass.

 

[skidsteer.ca]

Ken - with those hours i seriously doubt there is a problem with the relief valve seats.
I'll send the pics when i get home, can you flick me an e-mail to remind me too?
Yeah, those plates aren't too expensive, about 100 bucks, 500 from my local dealer! the rotating groups aren't that expensive either. The last set i needed i paid under $500 USD each for. You can repair the plates with sandpaper and a sheet of glass.

I flow tested the charge pump tonight, it puts out a steady 6 or so gpm at wot. Took it up to 800 psi, and the flow stayed steady, so that pump seems good.
Try the hydrostat tomorrow, I guess.
Ken