Hi everyone 1 have a 973c with light coming on for charge pressure and then machine stops where can I check the pressure. Also light only comes on when you put it into forward or reverse high or low idle. 2 codes were loved non active 079 299-13 which I think is for forward and reverse lever calibration. And the other is 079-133-07. I assume that has something to do with the charge pressure.
The charge pressure releases the brakes, if you lose it the brakes will come on. Get the controls calibrated next and see how that helps. Later Bob
Hi bob thanks for responding code keeps 079-133-07 coming back. 133 I think is a solenoid over ride and 07 means mechanical failure ? Is the charge pump a small one mounted on back of big pump on left side. The brake is mounted inside the track motors ? This machine has 17400 hrs and don't know if motors were ever done.
Yes the charge pump is mounted on one of the main travel pumps. It pressurizes the loops and holds the brakes off likely more things I can't remember. The brakes are controlled by the travel lever in or out of park and the bottom of the center peddle travel, most of it's travel just slows down travel. Later Bob
The brakes are between the he travel motors and final drives, you need to pull finals off to service the brakes.
079-299-13 is the forward/reverse directional lever needs calibrating. 079-133-07 is transmission pilot pressure supply solenoid "not responding properly" - in other words the electronic control is sending an electrical command to the mechanical system and the result is not within the acceptable range. I would say it's not a problem with the solenoid because that would throw up a different Diagnostic Code, it's probably mechanical in the valve itself.
Thanks nite I will try the valve and do I need the ET to calibrate the forward and reverse or can it be done with the switches under arm rest I can see the readings when I go to mode 5 but they won't change when I increase or decrease.
I'm also working on an older 973 with all the linkages underneath it just started slowing down last nite and no matter what adjustments i do it's not helping. Any ideas.
You don't need ET to calibrate the F-N-R lever - you need to be in sub-modes 7, 8, & 9. Send me your e-mail address by PM and I'll forward you the procedure. It's too complex to post here and there are diagrams in it which won't reproduce anyway.
Thanks Nige. Email is pasinead1991@ yahoo.com
First check the control peddles are free and not seizing up. Get it some place you can drive straight then pull up on both steer peddles and see what happens, then check the center peddle. Make sure you are getting full RPM out of engine. Disconnect and plug the two speed hoses at the motors to ensure they are getting into high speed. Then change and cut filter. Later Bob
You have mail ...................
Thanks bob where is the cut filter located. Tks.
The one in the housing top front center of the HPCU, be sure to drain filter before removing filter. Later Bob
Bob, a little off thread here, but where do the later 963's get their brake release pressure from, and what pressure should it be? Thanks, Brian
Thank you very much for your help.
Hi Bob and Nige Pat here how do I know if the full throttle lever in the tranny is adjusted correctly. All foot pedals are free and linkages are all well lubed. The throttle on engine is getting full throttle. I adjusted throttle linkage for lever in tranny with control on cab at full throttle and I pull lever up till I felt lite resistance and adjusted linkage to pull lever a 1/4 inch past the resistance point.
Pat, does you machine slow down when at full engine speed, if yes will it speed up if you lower engine rpms?
They use charge pressure or pilot pressure in the manifold with the solenoids. It just turns on or off the other solenoids ramp up and down to control pump and motor swash plate angles. Pressure should be around 400 but you need to check a manual. If you are checking one with a pump stay below 400 or the housing can break. Later Bob
The center peddle linkage adjustment is correct if you can put a 5/16" bolt through the lever and thread it into the valve housing with the peddle up. Later Bob
It's the 973 older model with all the linkages no solenoids. When you increase rpms the tracks speed up and decrease rpms tracks will slow down it's just moving very slowly and no power from tracks. I want to make sure I have linkage correctly adjusted for full throttle at the lever at the back left side top of the HPCU.
If you mean the Underspeed override control from the bellcrank in the throttle linkage to the HPCU housing do this. Lock throttle in full speed notch, make sure the spring in linkage streaches about 5/8" , disconnect the linkage to HPCU, lower it down and lift it up until you just feel it hit a spring loaded pin inside and adjust link until pin just goes into the end. If the machine doesn't speed up at low throttle the filter isn't clogged. You may have a leak at the tubes under the cover. Clean the top very good then remove it and check the tube ends for leakage. Later Bob
Thanks bob will check that.
Thanks, Bob. I'm guessing you do a little work on these mounts....
I did until I retired last year. If you need to work on many get a power train Schematic, C models are similar 73 has separate hystat reservoir smaller machines share Hyd oil. That gives you more opertunity to do a system cleanout. The hyd components can cause that so no need to wait for a drive failure. Later Bob
Hi bob and Nige pat here regarding 973C when I start it all is ok but when I move control forward or reverse the light on top right of display stars flashing alarm sounds the machine moves fine but about 20 seconds or so the trany warning lite comes on and it stops moving and code 079-133-07 sets. That's override solenoid has a mechanical failure stuck or not responding. I replaced solenoid valve and it's still the same. Will low charge pressure cause this code. Any ideas.
Hi again I put gauges on manifold and are only getting 50 psi at idle and 200 at high idle.
It would but also wonder how much contamination is still in the system from the pumps. Dealer shops pull everything apart for thorough cleaning and a cooler wash. Need to put some gauges on it. Later Bob
Hi I found a manual on line it shows that there is two charge pumps but the 973c I am working on only has 1 mounted on back of rite side drive pump. I am only getting 50 psi charge pressure at low idle and 200 at high idle I removed charge pump took it apart and found very little wear housing. the relief valve looks good also the one on the ecm manifold.
The 973C has 2 charge pumps, one for each track pump. They are built into the track pump itself. The small pump bolted to the right side track pump is the pilot pump for the implement.
Thank you for that help in identifying the pumps. Is there a way to tell if the relief valve on the manifold is bad. Took it out and it looks good. It seems easy to push the valve off its seat when I press on it with a small punch and when I turn the adjusting screw in it dose t make a difference in the pressure to push valve off its seat.
Have you checked the charge pressure? The tap to do so is I believe the one towards the front at the bottom of the trans control manifold. It should have "chg" stamped in the manifold next to the tap. Pressure should be around 400-415 psi at high idle...going from memory here so consult a manual to be sure. I can look it up when I get back to my desk.
Just looked it up and it should be 415 +or- 15 psi. And it is the lower left tap, below the charge relief valve.
Yes I checked it you are correct with location of tap and pressure. I'm only getting 50 psi at low idle and 200 at high idle. If the relief valve was bad it would cause this. So dose that relief valve on the manifold works with both pumps if so then that would more than Likely be my problem. It's highly unlikely that both pumps could go bad they only a month old and system was well cleaned out all lines cooler and so on.
Yes I would think your problem is with that valve.
Thanks for the help
Hi every one I am working on a 973 older module there are 3 pressure check points on top of HPCU manifold what should the pressure be at those taps and witch pressure are my checking.
You should check the 3 taps on the front of the valve, they are Upstream, Throat and Servo Supply then on the RH side is the Charge tap. The pressure at upstream depends on oil temp and filter condition but when you pull the travel lever fully in with the brakes locked you should get a difference of 140 psi between it and the throat, servo supply should be 245 and charge should be 200. If charge falls below 125 the control will Vent Out and need to be reset( back to park and in again) Later Bob