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Cat 544J trans question

Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
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HogZilla Keeper
Thanks mg. I may tap into those wires and hook up a couple of meters to watch as I drive the machine to see it the short or whatever it is shows up if/when the failure occurs. Then I may do the wire replacement. I guess that's really what the manual means when it says to repair the circuit. It doesn't say straight out to replace the harness, so unless a bare spot on a wire is evident, I don't see a repair other than just running a parallel wire, or (much more troublesome, I'm sure) pulling a new wire through the loom. Some are pretty tight and even with wire lube that might be nigh on impossible.

But I will check cold/hot resistance on the solenoid first. 7-11 Ω I believe you said. Sounds about right for a 24V solenoid.

I'll give an update later today.

thanks.....again

tcw
 

Tony Wells

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Jul 18, 2019
Messages
635
Location
Tyler, TX
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HogZilla Keeper
Gentlemen, I congratulate you for your knowledge and wisdom. I may not have followed the procedures in the book precisely, but in spirit and practice. I checked the solenoid first as suggested and it was fine. Then instead of breaking every possible connection along the way (to avoid disturbing otherwise working circuits), I ran my test jumper all the way from the solenoid connector to the transmission controller in a single run. Just red butted for the test. Wrapped the wire safely out of the way and off we go for a test drive. This was wire T06 Blu, and I will label the sub for the next tech.
I drove the thing over an hour and a half, over hill and dale....smooth and rough, uphill and down. I did everything but try to drown it, although we do have ponds and the thought did cross my mind. It never even blinked. In the morning I'll go swap to MTW and solder and shrink the splices and wrap to the existing loom. Then just a couple of access panels and some trim.....all done

Well done, guys....couldn't have done it without you. Help most appreciated. I'm still not green-tagging this machine because of the low brake pressure warning light, so I guess I'll track down the pressure sensor and have a look. I must have pressure, it will throw you thru the windshield, so I'm hopping for a faulty connector, wire, or sensor. If I have to measure the pressure, I hope there is a gauge port. I haven't checked for electrical specs on the sensor, but couldn't check that too. Or just replace it. it's original.

Looking in the electrical cabinet, I can see it's been worked on by a hack, so no wonder there were so many codes. Lots of live wires just cut and laying. Trashy appearance. No telling what really works right and what doesn't. I'll work off the operator "crab sheet" for a start.

My local dealer/service center was not familiar with the Hall Effect FNR switch. Probably mad because I was right he was wrong. He didn't sell a new computer.....which wouldn't have fixed it anyway. Any chance one of you can get me the PN? I can order from Dallas or Houston just about as easy. I think unless it's twice the money the original style is, I'll update it. Will save a headache later, I'm sure.

That's about the end, or near it for this one. Already got another lined up, and I'm sure hoping someone here is a Kobelco fan. I have an excavator 20 miles from the shop (can't recall the model) that won't run. Computer full of codes (sound familiar?) and rodent damage to harness....somewhere. Looked at this one a couple of years ago and one of the codes doesn't exist, per a factory phone call.....oh well, I love a challenge. New harness is north of $10k, so planning to try repairing it. Everyone chickened out on me last time we wanted to use it, but need is more urgent now. Hate working on it where it is, and moving it seems like a project. Boom and Bucket are extended and sitting on the ground, cab is turned about 90°, so there will be some discussion about it and whether I really want to tackle it. But that's all for another thread, and I'll try to get the manufacturer correct this time. I'm really not that dumb :)


Again, many, many thanks for making me look good!

tcw
 
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Tony Wells

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Jul 18, 2019
Messages
635
Location
Tyler, TX
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HogZilla Keeper
mg.....got the new parts for that FNR swap, but no info with any of it, especially on the pigtail. The two main plugs fit the machine side of the harness, but no action. Since the new lever does not have a mechanical lockout for keeping it in neutral I must assume the pigtail is related to keeping it out of drive positions electrically. As I may have hinted, the local dealer isn't a lot of help. Is there an updated schematic that will show where the pigtail goes? Or can someone tell me? It appears to have a pin to replace one in one of the connectors, but I have no idea which one. I'm surprised, and disappointed I guess that there was no "revision" drawing.
 

mg2361

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Jul 5, 2016
Messages
5,057
Location
Pennsylvania
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Equipment Mechanic
The AT412433 H Series jumper harness is connected to the 1 pin weather pack connector near the base of the steering column. This is the ground wire to the wiper circuit. It is under the steering column covers. The service jumper will tee into the wiper ground circuit. The single weather pack terminal on the jumper needs to be inserted into the spare connector cavity on the machine-side mating 4 pin weather pack connector for the FNR Lever.
 

Tony Wells

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Joined
Jul 18, 2019
Messages
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Tyler, TX
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HogZilla Keeper
Hmm, I don't recall an empty cavity on the 4 pin weather pack connector, but it's probably there. Easy to get to, someone removed all the covers and they aren't to be found. Sounds good. I'll get over there this afternoon and put it on. Even as simple as this is, you'd think a single illustration sheet would come with it. I guess maybe it covers different applications so maybe it would not be so simple as a single sheet. Oh well.....as long as I get it done.

Thanks mg

tcw
 

Tony Wells

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Jul 18, 2019
Messages
635
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Tyler, TX
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HogZilla Keeper
mg, you were correct, as I suspected. The “empty” connector was properly plugged so I just didn’t notice.

All is well and I thank you.


Next on the list, as of this morning is a new/used/rebuilt suspension for the cab. No wonder my back is killing me. This one has hydraulic gas-springs I would call them. And they have leaked down so the seat is flat on the bottom and very solid. New one is mucho dealer bucks so won’t happen. Need to find a supplier. Seat itself is fine. Dirty but no rips or anything. Is there a rebuild kit for these things? Naturally the owner is in a rush, but that doesn’t change availability.

Got any sources to share?

tcw
 
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Tony Wells

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Tyler, TX
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HogZilla Keeper
Interestingly, from my quick glance under the boot with a flashlight, that illustration appears to be the same style suspension package as I have on the machine. I plan on removing it Monday morning so I can get a good look at it. Since it has just settled at the bottom, it could be as a simple as a leak, which might be repairable, or a cheap part. Kind of doubt I'll find a fatal part in that simple mechanism.

Thanks for that link!
tcw
 

Tony Wells

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Tyler, TX
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HogZilla Keeper
Now on the system illustrated, there is a bladder. That is to support the weight, as a spring would. The owner of the machine is under the impression that it is like a truck, with a engine powered compressor, that supplies all air systems on board, same as to power the trailer brakes, for instance. This machine of course, has hydraulic brakes and no air system at all to my knowledge. So....this begs the question (to settle our argument) is this bladder simply a constantly filled, closed system, or is there an external air supply required? In the case of a "flat" bladder, is there a way to refill it if there is a repairable leak? I'm planning on just replacing it. I wouldn't R&R (2x) the seat for the cost of the bladder, so to patch it is kind of ridiculous it seems to me. But if there are hoses and fittings involved, a leak look might be justified.
 

heymccall

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Feb 19, 2007
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5,352
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Western Pennsylvania
Electric compressor, hose (and wire) to rocker switch, hose to airbag. (All within the seat suspension assy)

Push rocker one way and compressor operates and air is directed to air bag.
Rocker in neutral and airbag holds.
Rocker other way and airbag deflates.
 

Tony Wells

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Tyler, TX
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HogZilla Keeper
OK...missed that detail in the lower left corner of the drawing. Working on laptop instead of big monitor at shop. So in that case, other possibilities open up for points of failure.....all the way back to supply voltage and switching. Which as it stands now, the compressor is not running. I haven't noticed a rocker switch so that might just be in off position, or there may be no power to the switch. Beyond that, it sounds like plumbing or airbag. It would operate without the damping shock, just would be a bit bouncy. First things first, I have to get the bladder to inflate.

Working on this machine so far I have found many cut or disconnected wires, poor splices bare wires twisted together....no tape even, and everything imaginable done sloppily on the electrical system. The "12 v center tap shorted or open" code seems to be that whoever made the connections has tapped the wrong battery. 50/50 chance. I'll probably have to go back to the fusebox and trace from there to find the problem with the compressor circuit. Oh well.....I asked for it.

Thanks heymccall

tcw
 

mg2361

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The "switch" for the air suspension on the "J" is just a little valve/switch combo on the front side of the seat (#10 in the illustration) which receives power from the F08 10 A fuse..
 

Tony Wells

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Jul 18, 2019
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Tyler, TX
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HogZilla Keeper
I did find that switch (S32 on schematic), 2 wires and a hose connected to it. Located the circuit on the schematic. It couldn't be much simpler. No tests yet, but will check supply first. If I read the op manual correctly, the compressor will run only with key on. If power and switch check out, compressor is suspect. Already gone thru all the fuses but there were a couple missing that I didn't concern myself with while working on the trans control issue. Will review the fuses if no power to the switch. So far, I have fixed or remade about 50 connections overall, some bare twisted wires, some taped, some not, several miscrimped spade and butt connectors, corroded grounds and a few that were just not made. There are still a couple of hot wires leaving the fusebox that I haven't traced down. Could be one is the seat. I presume it's 24V?
Thank you, mg

tcw
 

Tony Wells

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Pump, she no run. Bladder (spring) leaky. Probably ran the pump to death once upon a time. New parts ordered. 3-4 day delivery.

I'm not sure how exactly to get the seat out to maybe make this easier, but I pried it up and blocked it enough to get my hands in there. That scissor mechanism is pretty stout. Hope my blocking doesn't let go while my hands are in there. The top of the seat (cushion) was held on with sheet metal screws. Didn't look factory and now it has none in the back. No way to get to them. They broke with a little persuasion. Replacing them I'll have to figure out. Front to back slide is stuck. Release lever is stiff, and everything that is supposed to move doesn't. Should be interesting getting this seat back to factory shape.
Top half on this example was held on by 2 bolts. That released the seat back so I could see a little better what I was doing.

24 to switch is there, ground is good. Switch is good. Jumped it for good measure but still no pump. This will be a good time to replace those air lines too. They are getting a little stiff. If I can contort my body enough to get it all back in there, I'll be happy.

Last thing to fix on this machine is a false alarm on the service brake pressure. Dash warning light always flashing, but great brakes. Hope just a bad sensor or yet another bad connection. It's usable, but I don't want operators to get used to ignoring flashing warning lights on the dash.

Then on to the Kobelco. Not really looking forward to that, but I'm going to tackle it. Assuming I can get it moved. Still puzzling on the swing brake....but that's on the other thread.

Can't tell you guys how much I appreciate the help on this machine.

tcw
 

Josh R.

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Oct 20, 2020
Messages
3
Location
Bryan, Tx
Hi, Tony new to the forum here. Did you get your false brake alarm code to go away? I have a 544j giving the same 117.1 code. Brakes work fine, both pressure switches were replaced on the brake pedal. Code still returns, any insight on how to proceed?
 

Tony Wells

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Jul 18, 2019
Messages
635
Location
Tyler, TX
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HogZilla Keeper
Welcome to the group, Josh. Lots of smart folks here. You can get some great assistance from them.

Unfortunately, I never pursued that brake alarm. Machine owner really wanted it back to work and told me I could come back to it later “when I wasn’t so busy”. Well, that was just a nice way for him to blow off fixing it. I have months of project lined up. I really think I’ll never see that machine back in the shop again.

I didn’t really don’t have a recommendation for you right now, but I’ll look back at my notes and see what I wrote up on the brakes. Hopefully something helpful. Maybe someone else will chime in. I will say that my trans issue turned out to be a physical wire and you may have to dig in and do a few wiggle tests and do them again against machine ground. Many of these wires get flexed and chafed a lot so start basic and make sure the actual wires and connectors are good.

I wish you success and if I can find anything helpful, I’ll post it. My 544 collection has grown to 5 I think, and am about to get another

t
 
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