Cat 320b run hot since rebuild

[John C.]

You should be able to see that on the monitor panel and know for sure how much. Your rebuilt engine may have more horsepower than it does cooling system. Maybe run a cycle time on the boom up function as well.

 

[mitch504]

One wierd thing I saw on a Cat hoe once was an exhaust leak blowing into the radiator. You have a new muffler and have checked radiator w/ laser, so probably not it.

 

[walkerv]

Im reading everyones comments in going to swing by it in the morning on the way in real quick and see if they left a witness mark on the injector pump and mounting if i cant see nuthen im gonna call the guy up and ask him how he timed the pump , as the sis shows a spill timing method i dont have alot of experience with. I kinda grew up in the electronic era and all the old guys worked on the old stuff, this is such a simple engine it has to be something stupid , after looking and reading about the cooling system on this set up does the t-stat block off the bypass port when it opens im kinda wondering if it isnt a defective t- stat that isnt fully opening Even though it looked to have a dang good flow when i had cap off and water a tad low .

 

[Nige]

The generally-accepted number for a radiator in good condition is that it will drop the coolant temp by approximately 20 Deg. I’m wondering why yours is dropping it by 45 Deg...? Low flow..? even if it was allegedly rodded out during the rebuild. As others have mentioned it could also be the thermostat or even the water pump.

 

[airpower64]

i had similar issues with a ford pickup after an emgine rebuild. the problem was a bad radiator. The radiator was cleaned so i was notvthinkingvabaut it and turned out the flow was 65 precent of the new one
so that was my issue.

on one other time (im a pro mechanic) a car with a new wngine constantlybover heated , all parts even a new radiator was installed after 1 week trouble shooting , and 3 times pulling the heads i found out the waterpump impeller was slightly loose on the pump shaft and as the engine warmed up the impeller slipped on the shaft and the pump not circulated the coolant fast in the engine,.and the engine is owerheated slowly but surly . a small weld.on the pump shaft fix the pump and all the problem disappered.

 

[Mobiltech]

That temp drop on the rad is strange. I’d be looking for a flow problem.
Get another good reading from top to bottom of rad just to be sure.

 

[GregsHD]

Yeah that is quite the difference between upper and lower temps, I didn't catch that before thinking out loud... I've also seen strange flow issues from someone forgetting to remove a rag or plastic cap plug in the past! Very curious.

 

[Birken Vogt]

If you have exhausted every easier avenue of figuring this out, I would place insulated thermocouples at the engine top before the thermostat, one at the radiator inlet and one at the radiator outlet. Start the engine from cold and watch all three temperatures as it begins to warm to see when the thermostat opens and what happens with the lower temperature as the radiator begins to receive hot water and heat up.

 

[walkerv]

How much is the RPM dropping when a load is applied? Should probably be no more that 150 with the throttle dial at 10 and say booming down swinging and stick out at the same time. That fact that coolant temp drops so fast indicates the cooling system is working correctly. All the Cat excavator radiator caps are junk. Go get a quality one at a Napa store somewhere.

Yes you are correct about the cat caps . I plumbed in my cooling system pressurizer to the water manifold and built 4 psi and it leaked off quickly. Talked to the local cat house and they found where it said caps secondary relief is 12.5 psi , i managed to track down a carquest 13 psi cap and did same test was able to pump it up to about 14 psi and it bleed off to about 10 psi and was just barely seeping , installed new t-stat noticed a very different flow on warm up while i was topping of coolant it was cycling like an unloaded engine at idle should , when i turned of auto throttle and put it on 10 it opened and stayed flowing but seemed slower then before i think it may have been a defective t-stat after all. I stacked brush for about an hour stayyed 2 bars away from the red before it was touching the red about to yell at me . Need the guy to run it now what takes me an hour to oveheat took him 20 minutes so we shall see .

 

[walkerv]

Quick but long update, after i heat cycled it this afternoon i went back to it this evening after work and i worked as hard as a not run stuff everday mechanic can while stacking brush and such. Having the cooling system hold pressure has stopped the runaway heating issue i was having . I can still keep it very close to hot but could not push ot to overheat with my operating skills so its sort off a win so far at least im getting somewhere now . As this machines engine was taken out rite before i started and was worn out it likely wasnt running hot then then i saw the tag of the place that supposedly cleaned the radiator , lets just say they used to be good so i have my doubts if they actually unsoldered a tank and properly cleaned and rodded it. Im pretty much condemning the radiator now that i have a handle on things . If cat is reasonably priced i will get genuine but i will also check my mack dealer as they got me a radiator for a johndeere 8400t that i think was a better radiator then the original and is working fine 500 bucks cheaper and 5 days faster . And wouldnt ya know it this morning they traded in 2 excavators to james river and one was an identical 320c if i had known sooner i woulda traded radiators ohwell , will updated next week sometime after a radiator change .

 

[Tenwheeler]

I would not disregard removing something below the thermostat to bleed air. Do not that that is your problem but it costs nothing.
Then I would plumb a gauge into the back of the oil cooler, block or head. What is your coolant pressure at full throttle?

 

[walkerv]

I would not disregard removing something below the thermostat to bleed air. Do not that that is your problem but it costs nothing.
Then I would plumb a gauge into the back of the oil cooler, block or head. What is your coolant pressure at full throttle?

T-stat has a hole in it it self bleeds rather well i did pull the fitting out of the water manifold just to be sure found no air. Said fitting is an original compucheck fitting for taking coolant sample or checkin pressure didnt want to disturb that one without a replacment on hand. Gonna see if cat house has a spec for waterpressure if there is i will check it .

 

[guest]

I had a Case cx160 with plastic tanks it came apart at seam. Case wanted $2800 for new one I got one with aluminum tanks from activeradiator.com for $900 several locations across U.S. they can make anything you need better quality than what was in it.

 

[walkerv]

Active radiator showed a radiator in stock in texas but they cant find it so im 10 days out on getting one now that i have owner man approval. Will post results when i get there .