Hi i have a D6R LGP, S/N 9pn00598. I am having transmission issues, when i release the parking brake the brake light comes on the dash and if i go into reverse there is a 15 second delay, sometimes forward has a bit of a delay as well. I checked the codes on the dash and no active codes. I checked transmission pressure and it is at 420 psi, the left and right brake pressures are 400 psi with the parking brake released. Any ideas because i am stumped.
I'd suggest go back to basics. What does the oil look and smell like.? Have you checked the magnetic suction sceen in the transmission for metal or burned friction material.? Watch the monitor screen carefully when you release the park brake and/or shift the transmission. Does the SERV CODE icon flash even briefly when you release the brake or shift the transmission.? Try monitoring the pressure when you shift from neutral to either reverse or forward. Does it dip more in one direction than the other.? What about the time it takes to recover back to max pressure.? Any difference.?
So I just changed the oil and filter, cleaned the screen, fixed some leaks, no serv code flashes even when I release the parking brake just the brake light is on. The pressures don’t drop at all, maybe 5 psi if anything, but it still takes 15-30 seconds to go into reverse
I re-read your OP. You said - "when i release the parking brake the brake light comes on the dash". Surely the park brake indicator light works the other way around.? Are you talking about the "brake system warning light" #6.?
yes sorry the brake system indicator light
I checked pump relief valve pressure and its at 430 psi no matter if i put it in gear or not. The left and right brake pressures are at 410 psi and the priority valve pressure is at 155 psi and 440 psi.
If those numbers were at Low Idle with the park brake ON/OFF respectively they sound right. Did this problem get worse over time or has it just suddenly appeared.? When was the last time the transmission clutch modulating valves were calibrated, and the brakes for that matter.? They can be done either with ET or with a Click Box if you have one. See attached.
So I am not sure when they were last calibrated, I only saw this cat when the engine blew up a couple months back so I rebuilt the engine, fired it up and this is the problem I am having, I was told that it seemed fine before but he wasn’t sure. I do have a clicker box
Not sure I care much for the word “seemed” but if you weren’t there yourself it’s all you have to go on. Can’t hurt to have a go at all the calibrations, even the steering and brakes.
Yah that is my next thing i am going to do, So being that it is delayed to go into reverse is it a posibilty that the reverse piston bypasses until it locks in? or would i have a pressure drop if that happens?
Always a possibility, but I would prefer to bet on a lazy (as in - not recently calibrated) modulating valve.
Hi Nige, on this calibration specification table the column's are sales model then steer type, trans type, track type and then App no, what does the app no mean?
"App No", or Application Number to give it it's full handle, is a Code that effectively configures the Powertrain ECM with an "identity" so that it knowns exactly on what machine model with what type of controls it's installed. See Page 11 of the Calibratrions document.
I would suggest it might be an idea to check the Application Number currently stored in the ECM actually corresponds with your machine arrangement. As far as I can see 9PN00598 is a D6R Series I diff steer LGP machine. That would make the Application Number 713. Is that what's shown actually shown in Mode 5, submode 1.?
No it says 706
which it says in the table as a standard track type but this is definitely a LGP
9PN-prefix are definitely LGP tractors. Has someone been messing around.? Maybe swapped a powertrain ECM into your tractor from another machine.? Try setting the parameter to 713 and see what happens.
ok i will try that, i am just waiting on a park brake solenoid as it tested out bad and i was getting a 681 F05 code that is active. There is a good chance that the powertrain ecm could have been replaced at some point in the last 26 years, it also has 19000 hrs on it
i would just like to mention that the code 681 F05 is a logged code when the park brake is on and a serv code when the park brake released, but when i don the test to check wires back to the monitor it tells me it is bad, plus when i took the solenoid off it had melted rubber from where the wires go into the coil
Is this any help.?
Yah that’s the test I did and the result of step 1 was to change the solenoid
Ok finally got an update, ended up having to replace the reverse modulator valve, i did the calibration for all clutches and also the clutch fill (with the clicker box which is an extremely pain in the ass but i got it). Everything seems to be working fine, thanks again Nige for all your help.
Agreed, but if you don't have access to ET it's your only hope. Glad it worked out for you. What happened when you changed the Application Number.?
Nothing seemed to change there
Good to know. I didn't think it would change anything but wanted to be sure if the question ever came up again. It may change some clutch engagement parameters with the extra weight of the LGP undercarriage & finals to prevent over-stressing the drive train, but that is pure supposition on my part. Thinking about that, did you change the App # before or after the calibration.?
Before, I think it has something to do with the diff steer being a lgp, but I never noticed any change