Hydraulic temp warning light on a 6415

rjglenn

Member
We have a 6415 with a hydraulic issue. The hydraulic temp warning light blinks after a few hours of operation. We recently had the radiator worked on due to a leak, and after the repair this problem came up - it was fine beforehand. We had asked the local JD place about using aluminum radiator stop leak in the radiator and they said it would cause problems. So is this true? I think somebody (not me, I'm inclined to take their word on things like this) may have put some in it after the radiator was patched.
 

LETHAL GTS

Member
Sounds like you have diagnosed your own problem.
Talk to the rad shop where you had it repaired.
I'm guessing the rad doesn't leak anymore, but it's not doing the job it was intended for either. Can you see where they repaired it or did they use gunk to plug it?
Gunk is not good unless you are in the middle of New Mexico with a SUV full of kids and need to get home. LOL
 

jd110

Member
The 6415 uses a dual cooling system. the radiator has two separate cooling circuits. The "cool side" runs at 140 degrees and the "hot side runs at 180 degrees. The cool side cools engine oil cooler, inner-cooler and hydraulic cooler. It also circulates through cab heater. It could be air trapped in system(it needs to be bled out). Also the drain valve on bottom of radiator may not be shut off properly. If not fully closed, it won't leak, but it lets the two sides of cooling system mix, which cases whole system to run at hotter 180 degrees. Also if radiator shop is not familiar with split system, they may not have sealed the two side properly causing them to mix.
 

rjglenn

Member
Thanks for your reply. We will check this. I don't understand why they have to make this so complicated. I've worked with & on tractors all my life and never had a tractor that was so picky...
 

jd110

Member
Unfortunately it is getting alot worse instead of better. It is all driven by the emissions requirements the government is placing on diesel engine manufacturers. The 6415 is actually a pretty simple system compared to the newer models.
 

rjglenn

Member
Oh well, we screwed it up real good today. Drained all the hydraulic oil, replaced both filters & cleaned the metal screen in the bottom. Filled it back up with oil, followed the procedure in the operators manual to the tee. Cranked it back up, heard a clattering sound and now the only thing that works is the power steering. I guess we'll be dragging it up onto the equipment trailer with a wench and taking it to the tractor hospital. Sigh...
 
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