Jd 6420 radiator bleeding
- Thread starter Pwquist
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- john deere 6420
I'm trying to bleed air out of the radiator. I believe that I have air trapped in the system which is causing the transmission to overheat after a couple of hours of operation. I'm trying to locate where the bled valve is located on or near the radiator.
Do you mean the hydraulic cooler?
The radiator would cause the engine to over heat but I wouldn't think the trans. Is the engine running hot? When was the last time the front screen were blown out or cleaned?
When was the last time the hydraulic and trans filters were change? There might also be a sump screen. We have a 6605, the only time we have any issue with the trans it is one of these 3 things, or dust plugging the front coolers. As far as a bleeder valve, I don't know of any on any Deere I have worked on. Only drains and fill caps.
Are you also sure it is over heating? Sensors fail, replaced a few of these too on different machines. This came up under one of the machines here not that long ago, I think it was a Deere. The sensor was bad, once the trans go up to a certain temp, well below what over heating was it would light the warning light.
The radiator would cause the engine to over heat but I wouldn't think the trans. Is the engine running hot? When was the last time the front screen were blown out or cleaned?
When was the last time the hydraulic and trans filters were change? There might also be a sump screen. We have a 6605, the only time we have any issue with the trans it is one of these 3 things, or dust plugging the front coolers. As far as a bleeder valve, I don't know of any on any Deere I have worked on. Only drains and fill caps.
Are you also sure it is over heating? Sensors fail, replaced a few of these too on different machines. This came up under one of the machines here not that long ago, I think it was a Deere. The sensor was bad, once the trans go up to a certain temp, well below what over heating was it would light the warning light.
The 6420 has a hydraulic oil cooler that has engine coolant flow through it for cooling. The cooler is mounted behind the engine flywheel and coolant lines run to it. The cooling system is a dual temperature setup. There are two thermostats. One is 180 degrees that cools the engine. The other is 140 degrees and this part of cooling system cools the hydraulic oil, engine oil, and intake air cooler. It is possible for sysem to be air locked. The place to bleed it is the highest spot which is the upper hose on the intake air cooler. Just loosen the hose clamp on the upper hose. Start the engine and partially remove the hose until you get coolant to come out. then reinstall the hose and tighten the clamp. Also be sure to check for any kinked oil lines that feed the hydraulic oil cooler. It is also possible the the radiator could have an internal leak that is mixing the 180 and 140 degree coolant. The earlier serial numbered machines used a radiator that had black plastic upper and lower header tanks. Some of these were prone to the internal leaking. the later models had radiators with aluminum upper and lower tanks. I haven't seen any of those fail. Lastly, it is very important to keep these systems to the maximum fill line in the clear plastic tank to keep air from getting into the low temp circuit.
Tx Jim
New Member
JD110
Do you have any idea/reasoning why JD would utilize a liquid instead of an air hyd oil cooler?? It would seem to me that 95 degrees air would do a better job cooling than 140 degrees coolant.
Do you have any idea/reasoning why JD would utilize a liquid instead of an air hyd oil cooler?? It would seem to me that 95 degrees air would do a better job cooling than 140 degrees coolant.
JD110:
Is this the way all 6420's coolers are set up? Or just the IVT's ones? I didn't know that was an option on this model (this doesn't say which one) I didn't know till I looked to see what trans were options on this model.
Is this the way all 6420's coolers are set up? Or just the IVT's ones? I didn't know that was an option on this model (this doesn't say which one) I didn't know till I looked to see what trans were options on this model.
According to this, there is a bleed valve and the only way to find it is the operators manual for your tractor.
Engine or hydraulic system overheating : Coolant system low on coolant in 6020, 6030, 6030 Premium, 7020, 7030 and<br>7030 Premium Series Tractors.
Engine or hydraulic system overheating : Coolant system low on coolant in 6020, 6030, 6030 Premium, 7020, 7030 and<br>7030 Premium Series Tractors.
Funny though, it doesn't show in the Deere online manual. Under draining and filling coolant, nothing about this.
http://manuals.deere.com/omview/OMAL152844_19/?tM=HO
http://manuals.deere.com/omview/OMAL152844_19/?tM=HO
MightyReek
New member
In older radiators with plastic top/bottom covers the bleeding is on the left side of the radiator. It's an oblique plastic valve that has a hose connected. You have to turn it left to open with a 19mm wrench.
In full alluminium radiators the bleeder is a plastic screw in the front of the radiator, in the bottom. It's a 10mm allen screw.
In full alluminium radiators the bleeder is a plastic screw in the front of the radiator, in the bottom. It's a 10mm allen screw.
