So long thread ahead sorry bought a 963c at the first of this year that I thought was a good machine run like a raped ape. Got to where it would slow down in a hard push no bogging just slowed down and wouldn’t come back until I cut off the machine then started it back same pile same grade it would do like it’s supposed to. I thought it needed calibration so cat comes out no plug on the machine to calibrate. They come out again wire plug up calibrate machine gets a mind of it own takes off by itself wide open in reverse. I shut it down it won’t start back cause the pump is stroked up. Tech works the rest of the day trouble shooting gives up going to send a different one out he come out a week later find metal in case drain filter says drive pump is gone. I stop them and take it in they install drive pump then they say drive motor is damaged beyond repair they put machine back together ( I’m leaving several little details out trying to make it as short as possible) No change pumps stroked up takes off by itself. They say they can’t get it to calibrate. They have another 63c beside it taking off parts and nothing is changed they called the other day say they think it’s mechanical because wiring harness is unhooked sometimes it go one way the next it go the other way. Now they say they have no idea waiting to hear back from cat to see what do try next. Sorry for the long thread has anyone seen this before any help is surely appreciated.
I would be looking very hard into why it will not calibrate. Which function is not calibrating? Have they tested any pressures and checked speed sensors and solenoids. Does machine take off as soon as it starts? Not sure how it could if brakes are still applied and not sure starter could turn engine fast enough to start if pumps were fully stroked.
Pumps are not stroked now new crossover valve stopped that. Fire it up and 10 secs later it takes off
Does it ever give a reason why it fails calibration?
Why were they looking for a plug to connect ET to do the calibration.? Does it not have the three switches located under the armrest like all the other track loaders of that generation.? If it does have the switches, on that basis alone you have to seriously question someone's competence level.
No they said they’ve never seen nothing like it.
Yes it has the switches they told me they couldn’t calibrate without plugging the computer to it said. One tech told me you couldn’t really get it right without plugging the computer in it. I don’t know. All I know is I’m going to have a 38k repair bill and nothing has changed!
I'm sorry that is not correct......... It's perfectly possible to calibrate the machine with the switches, or at least it should be. Post a Serial Number and I'll send you the chapter and verse from the Service Manual.
We need some input from CMark regarding the symptoms in your OP that resulted in you calling in the dealer.
2ds01084
Thanks. Keep an eye on your PMs although it may take a while because it involves multiple documents.
You never mentioned before if you had any Diagnostic Codes showing on the Monitor Panel. Is the SERV CODE icon lit after the panel self-test after the key is turned on for the first time.? You do not need to start the engine.
No sir there were never any codes what so ever.
OK, thanks for clarifying that. The question was one I failed to ask earlier.
All very strange. If there was no service tool connector then someone has stolen it. Even so, this is one machine where the laptop is of no use in performing the calibrations. As Nige said, it is done via the switches under the armrest. There are electrical safety interlocks to prevent the machine moving without any command so if it moves with the wiring harness unplugged then I agree, it has to be a fault either mechanically in the pumps or in the pilot hydraulic control system for the pumps. When you say it takes off, does it go straight or just one track? Quite what they have done to go from a reasonably well running machine to the current situation is anyone's guess.
They told me it does something different everytime they try it. The plug had been cut off by the previous owner i guess and they told me friday they changed the main hydrostatic control valve and no change problem is still there waiting to hear back from cat on what to do next.
We're the Cat techs throwing parts ar it because they couldn't figure out what was wrong? For 38K it should definitely have significant improvement not we replaced this and replaced that and still can't figure out what is actually wrong.
Clarify "no speed out of it"? If it will only move at a crawl, this suggests the underspeed feature is cutting in. Check engine RPM at high idle and whilst moving. If it's low, may be an engine issue. Is the microswitch on the governor lever working OK? If it will only move at walking pace, the motors may not be shifting into high speed.
And another couple of questions. What is the part number of the new pumps? Ask your dealer to check Simsi to see if PS50431 has been carried out?
0r0850 is the drive pump number. Ok and I will if they would ever return a phone call last I heard from them was a text 2 weeks ago I’ve called literally 10 times in the last 2 weeks and no response. What is the ps50431 thanks.
They said it would only travel at a crawl.
What a mess. Why do I think at the end of all this it's going to be something continuously overlooked and unrelated .
Most of the time when that happens nobody will admit what they "overlooked" Had a 53 that had a slow track speed and no push power. I could not figure it out so called in the Cat guy. Took him two days to figure out (or more like notice) that the tac was reading off by 50 rpm at high idle (laptop was showing the rpm discrepancy). Very simple repair (adjustment), some folks would have had a problem paying that bill, not me. He is still the guy I ask for when I need help, to bad he is going to retire later this year.
They told me they checked the rpm and the full throttle switch all that is good they said. And it is a mess they’ve had engineers there technical support people there they said the a lot of the safety switches have been bypassed.
Isn't a new harness installed worth a lot less than what you have paid out. Especially if some safety switches have been by-passed. Wired according to schematic might be good starting point. Simon C
That would be my vote as well. Electrically-speaking put it all how it was intended to be from the factory and start from there. TBH that really should have been Step 1 in the troubleshooting process.
0R0850 is the correct part number for your machine as it left the factory, however... Around 10 years ago, there was an optional rework to replace the pump controllers and transmission software to address a low speed surging issue. This is detailed in REHS1335. Even though it was optional, a LOT of the fleet were converted. If the machine was converted, the 0R0850 pumps will no longer work and will need the existing (REHS11335, part number 2171390) controllers removing from the old pumps and installing on the reman pumps. That's why it's important to see if your machine has had the conversion.
SIMS is, amongst other things, Cat's database of work carried out to individual machines. PS50431 (Product Support 50431) is what will show up on your machine's record if the conversion detailed in REHS1335 has been carried out. The actual service letter is SEBE8028 but is restricted access so I can't share it. Your dealer can see it though
Just got off Just got off the phone with the they said yeah yeah yeah yours has the conversion. Ecm didn’t change anything got the drive motors back on after taking them off and sent to hydraulic shop for there goof up of try to slow them down. Now he says it’s running 15 mph and losing low speed. He says they don’t have low speed levels 123. So who knows
So did they or did they not swap over the pump controllers?
He said they did
So now to me it sounds more like a motor problem rather than a pump problem. But then again I'm a million miles away from it and diagnosing things over the internet can only get you so far.
He said they put gauges back on everything now 2 technical guys are coming in the morning go go over things with the tech working on it. He said they’ve never seen anything like this before!!
Lol. Translation: Nobody here has a clue either so we're sending two guys just in case one of them stumbles upon the problem.
Exactly!
still not fixed trying a 3rd set of drive pumps this week! 9 months in the shop this is a damn joke!!!!
Are you able to get out there as a workshop visitor and get some pictures of the pumps?
Yes
now cat says they have a problem with the main rebuild center in Georgia supposed have 2 new drive pumps from Germany arriving today going to test them on the bench before installing t
Good grief!
This is not a new problem out of that rebuild plant. It is ongoing and not all the plant's problem. Cat is not the easiest to deal with in remanufacturing criteria.
holy crap Ill stick to my old 955L
Well still in the shop engineer flew in today said it needs a new drive motor which has already been replaced with a 6 month warranty that went out sitting in there shop. Said the software has a problem with the new drive pumps in the transition period from low speed with the pumps to high speed with the motors that this is old technology there dealing with and basically my machine will b operational but not like it was before.
Unfortunately, it sounds like you need a good lawyer…or a better Cat dealer…
Did you ask the dealer about my points made earlier in post #27?
This story highlights an uncomfortable truth about "new, modern machinery". It may work like a hot dam while it is new, but get a bit of crap in the lifeblood (hydraulic oil) or have an electronic box blow its brains out and you are hooped. That 963 basically consists of 6 parts: diesel engine, 2 pumps, 2 track drive hydraulic motors and the hydraulics brain box. Engines can still be rebuilt properly almost anywhere. Hydraulics and the brain boxes are a different animal. And you are beholden to those that can fix the stuff. The replacement hydraulic parts are pricey and don't lend themselves well to the small guy fixing them. A transmission (for example) can be pulled out and rebuilt by almost anyone but a hydraulic pump or motor takes a lot more tech (and $) to get it right. Bend over a barrel... Mudober said it right (#42, above)--stick with the older tech (at least for the small guy or the farmer) When repairs run to significant % of the machines first cost, the machine better be operating a very high % of its available time all year long to offset the repair cost. That may be a point that many smaller contractors don't realize. I'm one of those small guys- I finally pulled the trigger on an older Hyundai 290LC3 some time back for the farm. I was crappin bricks about the hydraulics. But the contractor that had it was planning on keeping it and changed out the main pumps and swing motor before he decided to retire and sold it to the guy that I got it from. I have a weak track motor but I hope I can live with that by concentrating on keeping the hydraulic oil clean and watching the contaminants in the oil and bypass drain oil flows. I have been poking around, looking for a 955-sized machine, but in seeing this thread I sure won't be looking at any of the iron that uses 100% hydraulics to drive. And when the dealer can't get the repairs right, as Tags says, "get a good lawyer". Jon.
Yes sir I did and they said yeah we’ve done been through that!
I'd be wondering if they just said that to not look dumb in front of you.
Well if they did swap the pump controllers from the old pumps to the reman pumps, I don't see any reason why the ECM shouldn't play nicely with the hydraulics. That's why I would be interested to see a photo of the reman pumps installed. Essentially, all the ECM is doing is modulating signal pressure to both the pump and motor controllers at the same time. When the pump controller is getting enough signal pressure to fully upstroke the pump, the motors take over using the same signal pressure to start to destroke the motors. In other words, the machine speed is mainly down to hydraulics. To be laying blame on the ECM isn't right, IMO.