Jd 6420 radiator bleeding

/ Jd 6420 radiator bleeding #1  

Pwquist

New member
Joined
May 21, 2011
Messages
7
Tractor
Jd 6420
M trying to locate the radiator bleed valve on the jd 6420 tractor. Can anyone help me out. Thanks
 
/ Jd 6420 radiator bleeding #2  
Do you mean drain?
 
/ Jd 6420 radiator bleeding
  • Thread Starter
#3  
M trying to locate the radiator bleed valve on the jd 6420 tractor. Can anyone help me out. Thanks

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.
 
/ Jd 6420 radiator bleeding #4  
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.
 
/ Jd 6420 radiator bleeding #5  
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.
 
/ Jd 6420 radiator bleeding #6  
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.
 
/ Jd 6420 radiator bleeding #7  
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.
 
/ Jd 6420 radiator bleeding #8  
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.

Symptoms

After several hours of work, warning system indicates hot engine coolant or hot hydraulic oil.

Situation or Problem


Coolant level in reservoir is between the "MIN" and "MAX" range but engine or hydraulic system is overheating.



Summary


Air is entering cooling system, hindering coolant flow. Check coolant level. Fill to the "MAX" line on the coolant reservoir.

Bleeding Cooling System:
The bleed valve (see Operator's Manual for location) on the radiator must be closed when the tractor is operating. Open the valve when coolant is drained or filled. If the bleed valve is left open, coolant will internally bypass between the low temperature circuit and engine high temperature circuit causing overheating. When bleeding the system, open the bleed valve and run the engine with no load for 5 minutes at 1700 rpm. Then shut engine off for 5 to 10 minutes before closing the drain valve. Check the coolant level. If level is below the "MAX" fill line, repeat this procedure until coolant level stays at the "MAX" line.
 
/ Jd 6420 radiator bleeding #10  
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.
 
/ Jd 6420 radiator bleeding #11  
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 the online manual, the bleeder is described as "Connect/disconnect control". They only show the older plastic tank radiator and not the aluminum tank.
 
/ Jd 6420 radiator bleeding #12  
By "bleeding" I understand "connecting both sides of the radiator to remove air", not purging all the refrigerant out.
Sorry for this explanation but sometimes different languages can frame us out...

Here it is.
This one is the old plastic covers model (sometimes the "transmission side" got blocked and the transmission oil starts to heat and then it became replaced by the alluminium covers model).
#31 is the bleeding valve

radiador_old.gif



This is the new full alluminium model, witch replaced the old plastic covers model and became serial from some PIN onward.
#22 is the bleeding valve, in the bottom, located in the front side. You'll find the base plate to have a lower part, clean it and you'll see the allen wrench plastic screw.
radiador_new.gif
 

Marketplace Items

MULTIQUIP LIGHT TOWER (A60736)
MULTIQUIP LIGHT...
2023 Unverferth 3PT 10 FT Perfecta Field Cultivator (A61307)
2023 Unverferth...
New Quick Attach Hay Spear (A61166)
New Quick Attach...
2020 INTERNATIONAL LT625 TANDEM AXLE SLEEPER (A59904)
2020 INTERNATIONAL...
1999 HYUNDAI DRY VAN TRAILER (A60736)
1999 HYUNDAI DRY...
HIGH END MINI GOLF CART (A58214)
HIGH END MINI GOLF...
 
Top