As a last resort, I'm going to ask a non Kubota question. I have 2 10yr old Case 420 skid steer loaders that are eating radiators like they are free. I had both radiators blow out the top tanks within 2 weeks. I replaced both and they blew out within 2 jobs. I ordered 2 more from oem, did a block test and replaced both thermostats. Those 2 lasted a short time. I am now considering going Kubota. does anyone have an Idea what the crap is going on? I have over 2 grand in radiators and am looking at needing 2 more.
Radiator problem
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Head gasket failure causing pressure build up in radiator maybe? Do a compression and leak down test.
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I did a block test with the blue liquid thing from napa and it didn’t detect any exhaust gasses. Do you know if that is adequate?
North Idaho Wolfman
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Have you run it with the cap off to see if there are bubbles?
I had an issue like that where the overflow was plugged and was breaking plastic tanks.
I had an issue like that where the overflow was plugged and was breaking plastic tanks.
Pau7220
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L3650 GST, Landpride TL250 FEL w/ Piranha, 6' King Kutter, GM1084R Finish
There has to be a pressure relief issue in the system. Even if it is a bad head gasket, it should still vent before damaging the radiator tank. Is it in the radiator cap, or remote somewhere in the expansion/recovery tank? If there is an inter-mix issue with oil, the petroleum will turn the rubber gasket in the pressure relief to glue. It doesn't take much to cause problems. I have seen this issue quite a bit in the automotive industry (Ford Taurus), But in most cases it will crack the expansion tank or pop the weakest hose.
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There were no bubbles in either radiator. I checked the expansion tanks and one of them was stopped tight. The other machine has a new expansion tank. The new tank replaced a broken tank. I am considering a leakdown test if I can find the tester. I can probably borrow one from Orielly auto parts. Do diesel engines have to be at top dead center to perform this test?
The majority of cylinder bore wear will be in the middle part of the bore,that’s where the highest forces from the piston will be against the bore
North Idaho Wolfman
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Staff member
Lifetime Member
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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
I would think a simple cylinder compression and radiator compression test should tell you a lot.
Interesting, I put my foot down flat out to pull into fast traffic in my 250ci ford wagon and saw a bit of "smoke" behind me in the rear view mirror. I drove up the road and turned off and idled around a trailer lot and the engine cut out/stalled. When I cranked, it was slow but started, I realized something wasn't right so I idled outside the gates, as it was about to close. Popped the hood, entire tank was split wide open.
I suspected a head gasket (common in this engine, had done one 100K miles previously, head bolts stretch) but put a radiator in it anyway. Found a slight leak down the side of the block from the gasket on the exhaust side, but very very slow, so I don't worry about it. But I don't floor it and hold it to redline anymore! I expect at full noise it may have been enough to blow through and pressurize the system faster than the cap could release the pressure. Certainly possible, but will probably never know, as it's not worth spending any more coin on.
I suspected a head gasket (common in this engine, had done one 100K miles previously, head bolts stretch) but put a radiator in it anyway. Found a slight leak down the side of the block from the gasket on the exhaust side, but very very slow, so I don't worry about it. But I don't floor it and hold it to redline anymore! I expect at full noise it may have been enough to blow through and pressurize the system faster than the cap could release the pressure. Certainly possible, but will probably never know, as it's not worth spending any more coin on.