So I've read a ton of forums on here about these things doing what mine is doing, my excavator looses power once temp gets to halfway, this spring I had radiators sent out and cleaned, I've tried new thermostat and no thermostate, I changed my speed sensor, all new filters, cleaned strainer in tank, I ordered the sensor for the pilot bank that runs the line to the main pump but haven't seen it yet, I've checked the banjo bolt on fuel transfer pump 3 times as well, I've used a heat gun on everything and the warmest thing I can find is the hose coming from top of swing motor, so prior to this issue we had an electrical issue, we had to jump the machine for several weeks while we waited on an altinator, altinator was re wired and machine wouldn't start due to a neutral safety switch mechanic said so he cut it, the batteries would get so weak I had to put jumpers on it to shut it off, maybe we fried something but I'm at a loss, the signal glass on the brain is green so it is communicating, any thoughts of why my hydraulics won't cool would be helpfull
Good day As I am understanding your post the heat gun is not reading the machine's results, you have two issues 1/ electronics 2/ engine power- overheating?. Jump-starting often proceeds a ECU failure. I would suggest begin with the battery check > charging check. If the machine has the possibility for error codes, it would be good to see what is happening.If you can give serial numbers, I am sure you will get Nige on board to help to get the machine sorted. Kind regards Uffex
So we can look at technical information please supply a Serial Number. For clarification are you talking about the engine cooling system getting hot, or the hydraulic system, or both.?
When it loses power, is the engine slowing down? or are the hydraulic functions slowing down with the engine staying the same speed?
So I changed altinator 3 weeks ago and four hours after the new altinator went in battery light came back on, this Friday I got to work and batteries were dead along with starter, I replaced starter and altinator and issue seemed to get way better it really didn't bog after that, I replaced the prv on Friday as well and problem got way worse, I can't calibrate it because my speed dial doesn't work so I have to dig into that next, any chance the altinator/ bad starter combination can throw these machines off that much, it's a grey market machine 7dk00548
I think the motor bogging was causing my heat issue
I don't know nothin about PRV's, but I bet it's a lot easier to fix the alternator. It's either putting 14V into the battery or it's not. Fix that first. I'd suspect anything the mechanic did to get it to work the first time. Then figure out how it worked for three hours then failed.
We've been here before...... For Parts & Technical information a 7DK machine is the equivalent of a US-market 6GK-prefix machine. For a Serial Number as low as yours is then machines up to 6GK00392 (there was a S/N break at that point would be the equivalent. Attached the electrical and hydraulic schematics for an early 6GK which will work for your machine. If you ever want a Parts Manual then XJBP7177 is the one.
So ran it for three hours this morning and battery light is back on and there goes my power, batteries have 28.7 going into them
28.7 is a little high if anything, you have that voltage even with the battery light on and no power? I'd start checking the voltage different places to see what power is going where, like cab hot to battery ground, to cab ground, etc. etc. The only other thing I can think to check is the actual temp while it's losing power, to verify if it's a hot issue, or an electrical gremlin issue.
We don't know why battery light has come back on, as soon as it does that's when things slow down, batteries r still charging we are at a loss
Nige says in trouble shooting if the connection p 3 on computer is over 14 volts computer is bad, I'm 14.4 idled up And 14.2 at an idle, still makes no sense it runs fine for 4 hours each time I put an altinator in it
Hang on a minute. You have a troubleshooting manual.? What is the reference number in the top RH corner of the cover.? Then I can post it up so everyone can see it.
126_206
Can you post a photo of the cover please.
It's a pdf someone sent me
First page of it
For anyone else looking in, here's the same document SENR6124-02 in a slightly different format. Also the SENR6136 that is referred to in the first paragraph of SENR6124. I don't have SENR6135 but I'm going to try to get hold of a copy. EDIT: The guy who might be able to help here is HEF member @anuradha . It might pay you to send him a message asking for help because he doesn't necessarily see everything that gets posted.
Any ideas where we should continue looking
It's definitely the hydraulics getting hotter than motor not sure what is causing the bog
Replaced by SENR6137. It comes in 3 sections - attached.
Hydraulics getting hot will cause the machine to slow down. In Cat 312's the problem has usually been down to -Faulty master relief valve causing pump to go to full swash -Fault hydraulic bypass valve causing hot oil to be dumped into tank directly (check if tank is getting super hot) -if you could give a full description of the problem how it happens and what happens in a more detailed description I think we can nail it down quickly. With the alternator there have been some cases the battery light has come on due to problems on the main computer misreading and you will find the battery charges ok and in most of the cases is a faulty rectifier within the alternator that throws it off and then usually the battery charging is affected
Ok so currently as we speak I have a battery light on, when I run machine she starts off great plenty of power other than my tracks I need to to do a rotary manifold, I'd say it's good power wise until just about the hydraulics get to the halfway point and it starts to slow down and loose power and motor begins to bog under a load, it looses allot of power half temp and past half temp, I did buy a new prv valve and put it in but the issue seemed to get much worse so I put the old one back in
so if you put a PRV in you need to calibrate it. Have you tried running it in manual mode (flick manual switches on right hand side and left hand side of arm rests) and see if the problem improves. I think the problem is the hydraulic oil is overheating (should be around 60-65C max). So the hydraulics would slow down. Is the hydraulic oil actually getting hot/too hot? have you checked the temp with an IR gun or something? Could be that the oil is getting hot so the PRV is not able to relief the pump correctly and thats leading to engine bogging down as well. first determine if the oil is actually getting hot regardless of the gauge on the display. and if thats getting hot you need to check the bypass valve and the master relief valve to see if thats what's causing the oil getting hot.
I've hit it with a gun once I go past halfway pump is like 184 which is hotter than I'm used to
to calibrate the PRV accurately you need a 0-50bar pressure gauge and tweak the PRV pressure range using the display. theres. a whole procedure to that and maybe Nige can share the part of the manual thats how's how to do it. you could do it without a gauge and ballpark it after a few attempts as well in case you can't access a gauge.
yeah thats too hot man and the machine would slow down for sure at those temps
I think the battery lights a bit of a red herring, the problem is in your hydraulics. Do you notice that you have to run the machine at higher revs when you first start it to get it to work at a decent pace? that could point to a relief valve issue. otherwise I think this could be yet another bypass valve. check the tank when the temperature is going up periodically and if the tank is getting hot then its the bypass valve. we have loads of these on all Cat 312/b/c etc and most of teh time people end up tearing up everything else before locating that tiny valve behind the main control valve. its so small you would never expect it to cause so much hassle. Its the hydraulics systems version of a thermostat so does exactly the same thing when it is and when its not working as the engine thermostat would do.
Takes for ever for hydraulics to cool down also, u have a Pic of a location of it? Possible it's jammed up or when they go they go? Would it cause engine to bog like it's under a load?
I do have a hiss in the valve bank that's been there since I've owned it
Well since the pump is not producing pressure and flow as per target the negative control system would cause the pump swash angle to increase and put more load on the engine. So it could cause the engine to bog down. so the return flow out of the control valve goes into a T and one side goes to tank and the other to the hydraulic cooler. Theres a nut that holds the valve in place and if you remove that its just a spring and a valve sort of device. We used to jam a few coins to hold the valve closed permanently as it was a tropical climate and we didn't really have a use for the warm up function!
Thanks man I will try in the morning, would it cause a loud hiss
not sure, could be the normal return noise. it could be related but can't be sure. one way to quickly check is that the return line to the tank should not get super hot because the valve should be shut, but quickest way to eliminate is to take the think out, jam it with a few appropriately sized coins and hopefully it fixes the problem pronto
I would do that as it would take you far longer each time to wait for hydraulics to cool to diagnose the problem "the correct way". you could just jam the valve first thing and see if that works first otherwise you won't be able to touch anything there with the hydraulic oil hot
You just put coins on top of the spring to hold it down?
Good day Loading hydraulics I would suspect to be the cause, high flow forced through small orifice. The pump is a common Kawaski, I would guess this is not backing down as it should. Are there any witness marks that the regulators have been disturbed ?
184F on the hydraulic oil isn’t anywhere near hot, probably about normal if I’m being honest. Without looking I would say the high temp alarm probably goes off somewhere around 230 or so.
Good day If the motor is loading it could be a symptom of failed pump regulation see attached may be of help. Kind regards Uffex
So pump is 186, going into cooler 167 and leaving cooler 146, oil looks burned
so cooler is working. have you checked the pipe that goes to teh tank from the main control valve? and temp of the tank?
Tank was in the 160s when hot
Can you run on manual mode and see if the problem reoccurs. Just wondering if the PRV solenoid is getting hot and not working properly when it’s running hot and causing your engine to bog down. If you run in manual mode the PRV holds at a constant level. It will bog down when you load the hydraulics up. But it shouldn’t get worse with use. I would say the hydraulic oil is hot but not too hot to cause the bogging down. Ideally you could measure the pressure from the PRV before and after the problem occurs to see if yhe PRV is the cause. It could be that the solenoid coil is getting hot and unable to open close the valve as it should. Only way to properly chcek that is to first see if it’s drawing between 0.1-1.0 amps when operating as that’s the normal window. And if that’s all good then checking if the PRV pressure is hitting 25bar when the arm And boom are held to relief. If that checks out as well then we would have to measure the main relief valve setting to see if that’s all good because if that’s set too high the pump could be loading up more than it should.
Manual or auto it does it
just to double check the engine bogs down from the go or just after the oil warms up? if you want you can give me a call, pm me and I can share my number
Bogs after oil warms up
My signal wire leaving altinator is putting out 14.2_14.7 the book says it should not be over 14, in talking to digger today he thinks I should put an inline resister in, what voltage should we set register to? We are thinking this is the issue
Where exactly are you reading that.? I have looked in the documents I uploaded and can't find any mention of it.
Page 126
OK, so that doesn't say the output must be a maximum of 14v, it says it should be "about 14v" which is somewhat different. I'm more familiar with 24v systems where the alternator output can go up to 30-32v before it becomes "abnormal". That would appear to indicate that on a 12v system the output could be up to at least 15v and still be classed as normal. Just my opinion though, and I do not class myself as an electrical expert.
So where should we go next we have worked on this every Day for 3 weeks
I'm sorry I don't know. I was simply trying to point out that I thought you were barking up the wrong tree regarding the alternator output voltage.
I was the one who was barking up the electrical tree, at the time there was a lot going on with the alternator, batteries dying, rewiring, etc. I may have been confusing this thread with another thread with electrical codes or warnings. 14.2 IS about 14V, even 14.5, 14.7 maybe questionable, but I'd have a hard time replacing a computer just for that. I still think from what you've described of the electrical history, that this is worth looking further into, but I can't guess where to look, other than follow the diagnostics through without skipping any steps. After you've verified the computer is getting all the correct voltages and grounds, then I'd think about a new computer if that's what the diagnostics tells you. 15V or 30V isn't a problem by itself, it's not hurting anything, it's more a question of what it's supposed to be and why is it that way? it might be hinting at the problem in a round about way.
2 questions this morning, a neutral safety wire on my foot pedals about the time this started could that throw wrong signals? Question 2 the pilot hose r4 leaving pilot bank and going to valve bank is pulsating bad, what does r4 control
So just an update I was able to get talked through the calibration of prv and we ended up cranking up the prv to get the engine big to go away, my pump pressure is 4500 with cold oil but when it gets to the temp where I loose power I'm down to 3300psi
Can you post the procedure you used to check/adjust the PRV? What is the pressure when cold after you made the adjustments? I have a similar problem on a 311B that I am starting to troubleshoot (I’ll start a new thread so as not to hijack yours).
What's yours doing
D Can you repost the So If you scroll up in the conversation there is links u can click on to access the manual, to calibrate it you need to hook hydraulic gauges up and than the rest is done from the monitor step by step
Similar to your problem I believe, after running for a while the cycle times for the hydraulics increases and the motor rpm seems to drop. It’s never severe enough to prevent me from working but it is noticeable. The hydraulic oil temperature gauge never shows more than halfway. I’m still in the early stages of diagnosis so I have not yet confirmed what the oil temp is when the problem appears.
I did find this today