First time in my life working on dozer. Happens to be D6N. This thing was working good, then walked 1/4 mile to next job site - now it will only start moving with slightly elevated RPM, will move for about 8 seconds and stall. Feels like park brakes locking up. With higher RPM stalls faster. No leaks yet, transmission oil level was low, put two 5 gal. ( total 10 gallons) of CAT TO-4 SAE 30 in it - and it is still low. Although if I say: “that dipstick is goofy” - that would be gross understatement. Can’t read that dipstick at all, and oil is very clean, even before add. At one point have seen something resembling light smoke or steam coming from behind the engine area. What do you guys think?! Am I dealing with TQ scavenging problem, or brake electrical problem? No S/N available at this time ( couldn’t find name plate where it was supposed to be).
How were you measuring the transmission oil level.? Engine stopped or engine running.? Does the dipstick have a Part Number on it.? If you can't find a S/N for the machine get one from the engine is another option.
Did it both ways, engine stopped and running. Like I said, the oil looks super clean, and that’s the main reason why I can’t definitely read the level! Dipstick is wet, but oil not dripping off of it when pulled out. But with that long and skinny tube - maybe it is normal. Still waiting for S/N from owner pulled from his records. Don’t have engine name plate, but have transmission one: BJG02248 Ar: 188-2003
Owner wants to just keep putting oil in to the transmission. I think without evidence of leak - he is up for dealing with big mess! Without leaks, even if level was low and started sucking air - 10 gallons should have taken care of the problem. Unless oil is not returning from TQ. IMO!
Based on transmission S/N the machine is ALY00993.
Thanks Nige!!!
Pardon my ignorance: the ending of transmission arrangement number is 2003, but ALY shows 2000. Do I get something wrong? Or it is 2000-2003 period?
Should I put dye in the oil? Ask Mystik for some of theirs?
Dye isn’t a bad idea I dye hard to read oil or if I need to chase a leak. Cat dealer has red, blue, and UV dyes.
I think red will do better job on that dipstick.
UV is generally marketed for fuel though, or at least that's how I've always used it. I tend to stick to either red or blue for non-engine applications. 9U-5031 (red) & 9U-5032 (blue) are the Part Numbers. 188-2003 is the Part Number of the Transmission Arrangement, not an indication of a year. D6N tractor Serial Number ALY00993 was built in France on 8th April 2004.
Thanks for clarification, Sir!
The only one that was available is 4861536, if it makes any sense.
What I did today, I stopped by the machine and stuck the dipstick through the filler tube, because i figured that dipstick tube was wiping and smearing oil on dipstick itself. Through filler tube it shows little bit higher then full, with engine not running ( didn’t have keys on me) and after owner dumped two more buckets of oil in it yesterday. But problem still persists! I still have suspicion that either oil doesn’t get scavenged out of TQ, or TQ leaking excessively and scavenge pump do not the capacity to pump all of it out. Still no leaks found ( unless belly pan is stopped up shut). Owner said they will drop the belly pan tomorrow. But I have my doubts that you can put 20 gallons in the belly pan, without it showing up somewhere. Right now exploring electric theory, owner said he was able to pull code yesterday, on Saturday monitor would not go in to diagnostic mode, no matter what how hard I tried. But then he said he forgot that code. Anyway, someone will show up with scanner today, and read the codes - that’s what he said. Forgot to mention - today weather is cloudy, so reading the dipstick is little better.
Updated Part Number for 9U-5032 blue dye.
Thanks again.
Does anyone know whether device brake potentiometer can cause the service brake code, on that machine? It gives the code for service brake switch, but behaves more like erratic value from potentiometer.
What code are you seeing.? Brake potentiometer.? Do you mean the PWM sensor that reads brake pedal position.?
I remembered the code number yesterday, do not remember it now. The only thing is I remember is it is “service brake pedal switch”. That thing goofy AH, it goes in to diagnostic mode once out of like 15 tries. Usually it will flash the “serv. Code” and brake lamp for a second when the brake pedal is let go after depressing it, not all the time either. When I use service brakes most of the time it stops the tractor very abruptly and jerky as soon as you touch the pedal ( way before switch is pushed, which is at the bottom of the pedal travel), and sometimes it will not stop the tractor, only slow it down to a creep when pedal is fully depressed. Sometimes it works fine, then brakes lock up and it wouldn’t move at all. Sometimes brake light comes on, but most of the time not. I should be back there this afternoon, working on it again. Did not know that angle switch can be PWM, always thought that PWM is something that ECM or amplifier generates based on analog signal. Judging by the diagram and looks of it - it is potentiometer, similar to the one that on de acceleration pedal, but different part number. But yes - the one that reads pedal position.
There are quite a few Components that are affected by the signal from the service brake switch. Here are a few options to jog your memory. (These are just the Component Identifiers, not the 2-digit Fault Indication that comes after) 0298 0468 0722 Based on what you've said above my bet right now would be on the brake pedal switch needing some "adjustment", despite the fact there is allegedly no adjustment on that switch. Or is it possibly the switch sticking or the pedal pivot needs lubricating.?
O! Yea! That was 289! Thank Nige. Only do not remember FMI of it. Switch adjusted properly, clicks when it should, maybe the contacts on the inside fell apart and making ruckus of a “disco lights” - who knows. But as far as I understand: to set that code potentiometer should have certain value threshold, indicating that pedal is at the end of travel, somewhere. So code should be if you have switch closing its circuit when pedal is not at that position ( close to the end of the travel), or pedal is there, but switch circuit is not closing. And then usual - short to B-, short to B+, and other fun stuff. Mechanically everything is moving freely.
Someone said that switch is going straight to solenoid, and only sending signal to TCM with side branch. I will check the diagram, but I don’t think that is true for this machine.
Those switches can be temperamental regarding "adjustment" and also how freely the pedal moves, especially when it is released and comes back up. First thing I'd do TBH is pull the pedal pivot & linkage apart, clean, lubricate, & see where that gets you. Attached the diagnostic for the switch (there is only one FMI - 02) complete with an abbreviated circuit. Also one for the pedal position sensor - not because it's giving you a Code but to see the explanation of how it works.
Thanks Nige! Everything is moving freely and adjusted properly, I can reach and move the switch with my fingers easily. And hear/feel it click with my fingers. I even tried to move the switch out of position, to see if it will set the code when it is out of range of correlation with the position sensor - and it does! So it seems like everything works kinda properly, but as soon as I get the tractor off of the parking brake - the fun begins. One more inter fact - when I switch the parking brake off - the code flashes for a second also.
Dang it!!! It might even be a #3 fuse!!! But probably not, pulling that fuse and not touching the brake probably should fix the locking up problem!
Wiring harness fault.? Corrosion.? Probably one of the hardest faults to track down when it won't stay active all the time.
Looks like it!!! I guess that’s “let the fun begin”!!! And I was hoping to get off the hook easy - by replacing switch or sensor!
And person who suggested that from the switch wire goes straight to solenoid with signal branch to TCM was right!
So, as far as I understand, the potentiometer does not actually apply the brake, it is acting as “inching” valve on earlier versions, simply slowing down transmission. Right?
Not really. It's a graduated method of applying the brakes. The signal from the pedal position sensor is an input to the ECM, the ECM output is a signal to the proportional solenoid (#12) on the brake valve. With the way you are talking about the service brake slamming on then maybe the pedal position sensor signal is dodgy somehow. The only way to tell for sure is to hook up a DMM with duty cycle measuring capability up to the sensor output. The duty cycle at one end of the brake pedal travel will be about 5%, at the other end about 95%. Either that or you might end up going into the brake valve.
Thanks again a bunch, Nige!!! You’ve been tremendous help. As far as I see I have problem with both of those, or their wiring. The code for the switch is when pedal depressed fully, and tractor creeps but doesn’t stop. And pedal position sensor does not set the code. Seems like might be wiring issue.
Your life would be much easier if you had a laptop with et on it. It would show you what the ecm is seeing. You can get a system pretty cheap that has et, sis , Cummins insight and a lot more. Makes your work a lot less stressful.
Agree! But not justified yet! For almost a year I didn’t do the heavy equipment at all. I am generally hydraulics guy, started out doing heavy equipment, but somehow never worked on dozers or any Komatsu equipment. Then it turned to industrial hydraulics and automation, then to screw compressors. Whatever customers want me to fix. This machine is one of my customers that I do other work for.
This seems like it could potentially be two separate problems that may or may not be related. 1. Brake pedal switch Diagnostic Code. 2. An apparent lack of brakes to completely stop the machine when the brake pedal is fully depressed. Maybe there is a relation between the position sensor signal to the ECM and the switch open/closed status such that when the sensor signal approaches close to the maximum value (say 90%) then the pedal switch will throw a Code if it has not changed status from open to closed by that point.? From the SysOp - " The service brake pedal switch operates independently of the ECM. The switch is a backup to the ECM and to the brake pedal position sensor. Normally, the ECM applies the left and right brakes according to the position of the brake pedal position sensor. The switch ensures that the brakes are engaged if either the brake pedal position sensor or the ECM are not functioning properly. When the operator pushes the service brake pedal to near full travel, the switch closes and a +battery signal activates the secondary brake solenoid. The secondary brake solenoid engages the left and right brakes by opening the dump valve. The fuse for the dump valve is the source of the +battery signal. This ensures that the brakes can be applied even if the ECM would lose power." So I guess the question "Is the dump valve opening.?" is also somewhat relevant , because that's what stops the tractor. In effect push the pedal all the way down to the floor and you are applying the parking brake by dumping the hydraulic pressure in that circuit.
You are right, mister Nigel! That will be a lot of fun sorting this one out. Plus I get intermittent output speed sensor 1 code, now! Haven’t traced wires from pedal sensor to proportional solenoid yet, but I suspect that it also goes straight to solenoid with branches going out to TCM for signal delivery. That’s only reason I can come up with, for installing PWM generator circuitry in the same device as potentiometer. Basically it is industrial style transmitter and output signal generator in one. Even industrials running PWM predominantly on output side, to control actuators. Only pulse related on input side is they use Hz. for temperature sensors/transmitters.
Does anyone know, if I just unplug the damn thing - should it set a code and go to a bypass/limp mode and let machine move? I am heading out that way.
It won't do that. The signal from the sensor is an input into the ECM. The ECM sends an output signal to the proportional solenoid from a different Pin, maybe even on the other ECM connector (there are two, J1 & J2). The electrical schematic will cough up the required info.
Tracing that F790-FJ119 wire right now. Have a suspicion that it will end up being F790-J31 wire on Contact 18 in TCM
Yep, turned from former to latter in Connector 24, and went to TCM. No Splices observed.
Well! The only thing left to do is drive over there, break out a backpprobing kit and Multimeter, and read the duty cycles. I had operator pulling fuse #3 earlier - didn’t help any.
Well! Showed up there just to meet the guy with scanner, he said at pedal fully released it shows 54%. Scan tool says it supposed to be 17%. Took the sensor off, started messing with it with flat head screw driver, and long behold - it is releasing at 17%! But there’s no adjustment slots in that darned thing! Anyway! Picking up sensor tomorrow from the dock after night delivery.
According to the troubleshooting procedure the sensor should be around 5% duty cycle at pedal up and 95% at pedal fully depressed. Where did the 17% number come from.?
Cheap Can-Do Chinese scanner. The values might be screwed, but one thing certain - that sensor is way out of wack, and needs to be replaced. And tell you honestly - I am glad that I wasn’t the one who had to make difficult $500 call. He condemned it - he will be responsible if turns out he was wrong. I wish the owner used that guy from get go, because I am swamped with my work, like crazy blind ox! Only messed with it because owner is my very good customer, and it was hard to say no. But that guy is not a tech, he just works at construction company, and they have bunch of CAT equipment, so they bought cheap scanner with On-Highway and CAT software. Today is Thanksgiving eve, so he got off work early and made the test.
Since I don’t have any scanner, I might look in to this CanDo OHV Pro. That thing slow as hell, but at least it is reading something. Better then nothing, don’t have much work that requires something better yet.
So, as far as I understand the new sensor will need to be calibrated. And from what I read one needs to have at least 4C-8195, to do that. Or can it be done without any special tools?
The sensor installed is not at its own lower stop, pedals shaft with slot is slightly elevate it, so probably that’s where 17% came from. 5% is probably sensors lower threshold not installed. And this what I stumbled across:
Anyway, mister Nigel! It was nice introduction to dozers for me! And one helluva teaching performance on your part!!! Thank you very much!!! Steering and blade was absolutely no brained for me, because that’s a stuff I deal with almost every day ( Rexroth A10VO, A10VG and A2FE), together with LS controls. And this machine has mechanical linkage blade control and not pilot. 3126 is somewhat familiar engine also. Had basic knowledge of Power Shift transmissions ( even rebuild couple of Clarks in my younger years). But transmission controls was total new deal to me! Thanks again for your help!!!
Clickity - click -click!!! Now I know what mister Nigel dedicated the famous thread to!
So this thing has been driving with the brakes half applied for a while. I would bet the brakes are fried and that’s why they don’t fully apply when it hits the secondary switch.
It was intermittent problem, and neither operator or me was giving it a gas when it happened. Operator said that it should pretty much start to go on idle. So when it didn’t happen we did not force the machine, or we could feel it had resistance. The guy that showed up with scanner, he did forced machine to drive by releasing decelerator fully, and you could tell it was struggling. But he was not there too many times, I think only two times.
Ok. I was just going by the fact that they walked it a quarter mile just before it happened and you had smoke or steam showing up. Now you said the brakes don’t lock when fully applied. Most operators I know say that just happened now!
They said it was walking fine. The problem started the next morning. Walking was done by someone else, not the regular operator ( he was at his chemotherapy at that time), another thing is the regular operator said that he never touched the brake pedal before, as we don’t really have hills around here ( that’s why we have problems with flooding). So the other guy who was walking it - might have operated the brake pedal and that’s when problems started. The smoke was coming out from TC area, but after we put 20 gallons of oil in the transmission, I didn’t see it again. That’s another goofy thing, even after adding that expensive dye to the oil - I still can’t read level when using regular dipstick tube. When using filler neck, it seems to show little bit overfilled at engine idling. I still think we might have TC scavenging problems, but brakes take priority.
Update: Installed new sensor, and as was expected - the machine did not started to move. Just with the new sensor it doesn’t flash “serv. code” and brake lamp every other time when switching to forward or reverse. And the same almost every time brake pedal gets depressed and let go. Only occasionally on brake pedal full swing movements. Talked to the owner, told him either set appointment with CAT for calibration, or if he wasn’t me - I will build the clicker box and try to do that myself. He said that for CAT it’ll be around $1000 just to come out, they will come up with any fee they can imagine to charge at least that. So I guess I am going to get busy building clicker box. And start looking for calibration instructions. And read them very carefully - so I will not screw up.
Another update: The guy with the scanner came in and calibrated the sensor with his cheap Chinese tool. Dozer worked for about 1 1/2 hours and started leaking from belly pan, that under cab. I guess we are finally getting our transmission oil level question answered. Who thinks it is scavenging problems?
Sorry! Forgot to do update in timely manner. The leak wasn’t transmission, but implement pump discharge hose burst, due to blisters in rubber. Although torque converter is all wet on top, but owner just wanted quick fix and back to work.
Yeah! That thing is a huge mess!!! Bunch of hoses in steering system have blisters in them and rub on each other. Spaghetti lines are cracking and two of them leaking. Almost all the harness pigtails have insulation coming off of the wires as soon as you touch them. Drive line is the “cleanest” part out off the whole cluster and constantly dripping oil for 5 days straight now, looks like I was right about scavenging problems and overfilling of the transmission. And looks like both seals are blown. Suction hose for charge and converter-cooler pump looking all mushy and kinked. The transmission breather was buried under at least 1” of crusty dirt (besides neglect - I blame CATs stupidity of not insulating A/C low pressure/return lines, which was sweating continuously, mixing with dust and making mud). Although there was supposed to be some kind of case pressure relief through dipstick tube. Torque Converter looks all covered in oil. Had a long and hard talk with the owner, he wants it fixed good now, after a few times it was “fixed” just to have another problem come up. Getting quotes for some of the smaller harnesses to see if it will be feasible to buy them VS re pin and splice. The only problem - I don’t know when I am going to do all of this! I am swamped with other work, and owner is hell bent on me doing the work, because I am “an anal stickler”!!!
I think I screwed up on the breather though! There’s something that looks like breather on top of the return manifold - but I cleaned it up more today - and it is solid piece of casting.
I’ve also jumped to conclusions too quick on the A/C lines ( I apologize - CAT) !!! After further cleaning I discovered that those are winch/ripper lines. Which is probably even worse, because it is the wettest part of the top of the transmission! Now I have to worry about leaks out of there also, like I didn’t have enough to worry about before.
Is that what I think it is ?!
And now I would have to re seal the blade control valve ( spool seals leaking) and brake solenoid block. Great!
Hell yeah!!!
And then some more!
You have you’re work cut out here!
Looks like it is just disintegrating. Is my memory correct by remembering some years ago Cat used some "environmentally sustainable" style wire insulation that ended up breaking down prematurely?
I have run into that on that C15 I am working to rebuild, ending up threw in the towel on harnesses and trying to make the ACERT cooked stuff functional, bought new and NOT regretting it.
It could be cooking, oil contamination, or a combination of both causing this type of effect on harnesses, but I've also heard of harness insulation flaking (mostly on excavators) around a similar time frame to the manufacture of this machine which was down to a change of insulation material. On the excavators there was factory support to replace harnesses where the insulation had cracked or flaked off but the programs expired long ago. The Problem Statement read- "The existing wiring harness insulation can crumble and flake apart. This may cause short or open circuits, generate Fault Codes, or other electrical issues." All goes to show that there is nothing to beat keeping machines clean...!!
YIKES!! Good luck with that! I'm glad it's not me having to deal with it. I got enough crap as it is.
Yeah! I have stepped in it! But it is what it is. Have to finish it now! . Same on having too much crap to deal with! As anyone who can use hands and brain at the same time, and willing to work, now days.
I use this phrase a lot lately: “ on the construction machines there is no unimportant leaks”. When you have dust - every leak inadvertently will turn in to disaster! I work on the portable screw compressors and have seen so many times where something like small leak of return fuel line that wasn’t taken care of, and series of wrong decisions - lead to machine being destroyed!
Yeeeap!!!
So, at this point I think the reason why the top of the transmission had about 2 1/2 inches of dirt/oil dried up mud on top of it, because spool seal, diagnostic quick connect on blade control valve, and port relief on ripper control valve we’re leaking for a long time, oil was running along the ripper lines on top of the transmission and mixing with dust. The proportional brake solenoid was absolutely buried in all of that, having about 5/8 - 3/4 layer of that substance on top of it. Not sure what’s with the piece of O-ring sticking out from underneath of the brake solenoids block, could be just drain passage - but it is still needs to be fixed. Have a boat load of dirt cleaning to do now, before I start to open anything up.
What do you guys think? Should I open up another “can of worms”?!
I think that before I had anyone working for me lay a wrench on that POS I'd tell the owner to rent a steam cleaner if he doesn't have one already and let one of his minions loose with it for at least a week. Drop the belly guards, lift the floor, & get the operator seat out of the way first obviously. Then once it's halfway clean you might be able to see what you're doing.
All of that ( besides steam cleaning) is already done by me. You can’t take that picture without doing all of that plus removing transmission oil filter hoses prior. I don’t really want to steam clean for now, because it will make a big mess, it is a lot easier to deal with that crumbly “mortar” that is mix of oil and dust with putty knife and some brushes. It is not oily mud at this point - it is half dried up oily mud. I guess the dust overwhelmed and plugged the leaks some time ago already. Some solenoids on that thing was located only by their pigtails sticking out from under that mud.
And looks like I am missing a bolt. And I don’t know if this hole is straight through in to transmission housing and now I have to worry about pump strainer - or it is blind hole!
From the picture that quick disconnect port looks like an SOS sample port because of the hole in the middle for a needle and because of the green dust cover. If it is it will probably be a 7/16 orb instead of 9/16 “ That threaded hole looks like a boss for mounting a guard or hose clamp. I wouldn’t be concerned about it leaking.
If you talking about one that leaks - I think it is implement system test port, it is at the end of the P gallery of control valve.
But I think you’re right - it is also a sample port.
It won’t be both. Cat has 2 different valves for that. The one with a hole in the middle won’t allow the gauge to attach.
OK. Thanks.
The hole is blind, and has thread tapped in it. So it is just a hole for some clamp to bolt on, or something like that.
I don’t know, was that Jerry rig or something, but those long ends looks like continuous O-ring. Which didn’t help, because there’s mud in the pockets, visible on the pictures, and the whole top of transmission on that side is dried up oily mud.
That housing looks like it’s corroded away at the sight oh the blow out. Might be worth a good cleaning and inspection
Agree. The question is why those ends are that long? Looks like someone didn’t want to fix it properly and put continuous O ring in it instead of proper seal. Although you might be right about blow out, there’s a brake in that seal only 1/2” away from that blow out site.
That housing is fubar’d . There is nothing for the o ring to seat against on the outside edge. It will probably blow out again.
Hope it is not too expensive to replace.
That’s what happens when you let neglect take place for too long!
Can one take it into a good machine shop and weld it up and resurface it? I guess you will find out how much that cover is worth and go from there.
Yep! Was surprised by small harnesses prices, not too expensive at all.
Good to hear.
I can't imagine the whole picture, but I imagine maybe you can put on a new o ring and create an extra seal from thin gasket paper. The question of whether the design allows to increase the gap between the lid and the housing ... This is worth doing if the housing costs a large portion of the dozer price.
Who knows what is up with those hard washers over and under the thick washers , on that manifold - are they supposed to be dished when new?
Looks like that manifold part that I need is 162-5357.
Nope. That's the complete Group. the manifold on its own is a 162-5358.
Thank you Nige!