After a couple years of resurrecting our LS4300 CII excavator we've gotten down to actually trying to put it into operation. The previous owner mentioned that it always ran hot but was always able to use it without problems. What we were experiencing since we got it running after it having sat for around 11 years is that coolant temperature will gradually climb to around 200 degrees on the gauge, then rapidly climb to over 240 degrees over the next 10 minutes when full power is applied. We've replaced the old oil cooler, we've drained and refilled the cooling system twice with nothing coming out of the drain that might suggest rust or sediment, and we once pulled the thermostat to inspect (but didn't do the boiling water test since it looked like it had been recently replaced). The motor runs strong and appears to have had some work done in the past, and the muffler replaced. Estimated hours on the machine are probably between six and seven thousand hours. My thinking is that if the overheating was caused by a clogged radiator the overheating would be a gradual and linear event, not the sudden non-linear rise in temperature that we get after the first 10 minutes or so of operation. Our present approach is to first pull the thermostat and see if that might offer a quick and dirty solution. We might also try adding a hot tank/steam cleaner powder into the cooling system that we use with our steam cleaner to try a flush with fresh water. The cooling system capacity is around 15 gallons. When we replaced the oil cooler we did a thorough steam cleaner blast through the radiator core since there was evidence of caked dirt and congealed oil that occurred over a period of time when the oil cooler was leaking. I think we got it pretty well cleaned, though it's hard to tell when the radiator was still mounted. So my question to this esteemed group is, am I possibly wrong in assuming that a clogged radiator, bad water pump, engine block clogging, or other cooling flow would be a gradual and linear rise in temperature? Again, the past two times we've drained the cooling system we saw no evidence of any debris, rust or other contamination in the coolant as we drained it. There is no symptom of head gasket leakage into the cooling system as the overflow tank is operating normally until the point of boiling over. Also, I had installed a 550 CFM dual 24-volt fan in front of the oil cooler to assist in pushing outside air through both cores of the oil cooler and radiator which is behind the oil cooler and am getting exactly the same symptoms. I'm hoping that the thermostat will be the culprit since it fits the (in my way of thinking!) the symptoms, but input from others on this forum is anxiously appreciated. Thanks to all, -Tom
Check to make sure the shrouds around your radiator is in tiptop shape. Fans are quite efficient , but like to pull the air from around the rad instead of forcing it through the rad. You can't believe how important this is.
We lost the original foam seal between the two cores when we first pulled the old oil cooler in attempts to repair it. To my disappointment the old oil cooler was all-steel construction and corrosion took its toll. I was looking forward to perhaps recovering some scrap value from what I expected to be a brass and copper core. The new one from All Radiator is a beautiful all-aluminum masterpiece that cost about 1/4 of what Link Belt wanted, but we didn't replace the foam seals, assuming that air flow would be sufficient. Pulling the oil cooler requires draining 55 gallons of hydraulic oil and loosing perhaps 5 or more gallons in the process. We have this down after having done it 6 times already between rebuilding the pump and trying repairs to the old oil cooler. But my partner, out of mounting frustration, might surely commit suicide if I even suggest that we might have to pull the oil cooler again, thus my search for an easier solution. I understand how complete sealing between the two cores would improve cooling substantially when air flow was originally from the motor fan PULLING air, but with my addition of the 550 CFM electric fan PUSHING more air through it seems to be a wash in our favor. But then, I'm always looking for suggestions from those with more experience and perhaps a clearer perspective. I DID buy a suitable foam on our first efforts to replace the old foam, but it was frustrating to try to get it aligned and stay put since we were working in the field and had limited resources and patience! And your suggestion makes sense too. I'll know in a few days once we've pulled the thermostat whether or not we're homing in on the cause. Then we can try getting back to sealing the air leakage as you suggest before trying again. Thank you for your input on this! -Tom
If you pull the thermostat put in a new one. The ridged foam pipe wrap that's split to go over a water pipe can be used to seal a radiator ,It's cheap and comes in different sizes . Bob
Thank you for the advice Bob!
Are you watching the temperature on manual gauges or the original LED gauge on the dash panel? Most all those machines had problems on those original dash panels. Have you run the engine with the radiator cap off? When the engine gets hot do you get a blast of coolant out the top of the radiator?
We don't have the computer module and are running in by-pass mode after many changes to the solenoid valve wiring and adding toggle switches. We're monitoring the manual gauge for engine temp. We haven't tried running it with the radiator cap off but I see what you're getting at, to see if there is obstruction in the flow path, right? We'll give that a try when we go up. I had bought a good black foam for sealing between the two cores when we first pulled the old oil cooler to take down for repair, but were too much in a hurry to get the machine back together rather than replacing what I considered at the time something "unnecessary". Yes, I'm sadder but wiser for assuming too much! BTW, we purchased a new oil cooler from A1 Radiator to replace the original after finding that although we stopped leaking from corrosion too many of the tubes were blocked. I thought there would be some good scrap value from the old cooler from brass and copper, but to my surprise the whole thing was steel. The new cooler is an entirely aluminum work of art. -Tom -Tom
I've seen the issue before but never was part of solving it. Most of the time I suspected compression gas was getting into the cooling system. I use a Stant cooing system tester that replaces the cap on the radiator with one that has a gauge hooked to it. I'll get a photo of my kit later today and post it. It has a pump that has the gauge. You can pump up pressure in the system and look for leaks. You can also just put it on and start the engine and see if you get pressure build up on the gauge as the engine runs.
Thank you John, and I have the Stant kit as well. We haven't had any indication of compression leakage into the cooling system, and things seem stable until we start running at full throttle for about 10 minutes or so and the coolant recovery tank starts to overflow. So we'll take a look at the system with the cap off first and wait for warmup and throttle up to look for anything abnormal. I underestimated the importance of sealing between cores to confine air flow, and will replace the thermostat with a new one as advised. Thanks again for all your help for the past couple of years. Despite the problems we've experienced in the past the machine runs strong. I sank it into our pond the week before last Thanksgiving when the surface gave way and sunk me into about 5' of the worst clay mud I've ever experienced. Despite working it for about two hours in my attempts to get out of the mess we finally brought in a similar Cat excavator day before Thanksgiving to get the beast out. But after a couple of hours work both machines climbed out and up a steep incline on the pond's edge. The bedrock had apparently been dug out into a deep bowl back in the later 1800's and formed what we now have as pond that provides water for our mining operation. Once I can resolve the overheating problem I hope my posts and pleas to this forum will be more infrequent! -Tom
Sounds like you have a lot going on with this beast. I won't even consider the complexities that could be going on in an excavator, I'll just focus on the basics. The add on electric fans are not a substitute for the fan working correctly. check the pulleys for bottoming out, rounding the vees, check the belt for wear, glazing, looseness. check the fan is pointing the right direction, some can be put on backwards still move air the right direction, but innefficient. use a non contact thermometer to check the engine temps when it gets hot but before it's blown any coolant out. Check the engine block, head, thermostat outlet to the radiator, water pump inlet from the radiator and post those temps here. Is there anywhere you can see inside the radiator, especially the hot side to see if there is any mineral deposits on the ends of the tubes? The temps will tell you a lot, but if you have a radiator plugged on the water side and on the air side, then it can look normal. Use a light on the other side of the radiator to inspect, you should be able to see through, or see the dirt. The sudden overheating happens when the coolant starts to boil, pump stops working, heat exchange stops. Stop running before that happens. Does it cool down if you stop operating? how long?
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Thanks for the tips. Yes, we checked to ensure the fan and belt were secure and adjusted, and we steam cleaned the radiator core before installing the new oil cooler. We're going to go back up with the non-contact thermometer gun and my Stant Radiator and cap test kit. And we'll install new foam seals between both cores as the originals were either missing or falling apart. I overlooked the importance of the seals earlier. Your explanation of the sudden temp rise makes perfect sense since the water pump doesn't do much when steam forms. As mentioned earlier, the overheating comes when running at full throttle. Idling back down after the overheating DOES allow the system to start cooling down, and the dual 15" electric fans seem to have aided substantially to the cool down too. I think the steps we take should either correct the overheating, or at least help us home in on the problem through process of elimination. -Tom
I dont remember if the radiator core runs vertical or horizontal in that machine but you need to shoot top and bottem or side to side with what the temps are , if that rigs pushing water out and its not compression then we need to know the temp differences on the radiator to give a idea if its plugged internaly .
Thanks for your input and suggestion of how to analyze the radiator. The problem is access since it's mounted behind the oil cooler. Best we could do is look at the inlet and outlet areas, but not the core itself. Flow is vertical . When we go up next we'll do a thorough mapping of the temperatures with the temp gun. Thanks to a number of suggestions already I think we should arrive eventually at either the fix, or least a better understanding of the problem. Tom
measure both the inlet and outlet of the radiator, top and bottom. And the thermostat housing and water pump inlet. Only takes a few seconds to measure. Do the measurements at least 20 degrees hotter than the rating of the thermostat, but before the boiling point of the coolant. So if you have a 165 thermostat, then 200 should be a good temp if you're not at too high an elevation with water, higher with antifreeze and a cap holding pressure. The measurements are useless if the thermostat isn't open, or the water pump is cavitating with steam.