Marccus
New Member
A while back, I was looking for a cooling system filter. I figured if we filter the oil, why not filter the coolant. There are several out there, but they are in-line filters with no bypass. I realize the chance that the filter would plug and stop coolant flow to the engine is almost nil, but I wanted a filter that would not obstruct flow.
John Deere makes a device that is used mainly by owners of their tractors. The "coolant eye" (also called other names by parts sellers) is an extremely heavy walled clear plastic tube that is barbed on both ends to accommodate hose from 5/8" to 3/4" with a slanted dip tube. At the end of the tube is a valve for draining the tube and sediment that is captured by the tube. You can also attach a hose to the fitting on the tube to flush out the coolant system.
The coolant eye goes on the outlet of the heater hose – which is the hose on the right if you are standing in front of the car facing the engine. It is an extremely tight fit to locate the coolant eye at this location and almost impossible to access the drain valve fitting from either above or underneath the engine. But the solution is just to remove the tube to drain and flip it upside down to back flush. Minimal coolant will be lost from the system when you remove it to drain or back flush.
The molded outlet heater hose must be cut in two locations. The first cut is made as the hose exits the firewall and about one to two inches into the straight section after the hose makes its 120° turn to the straight section.
The next cut is made one to two inches before the hose makes the 90° turn to attach to the coolant pipe. This is the critical cut for you are not left with much hose at this end. Cut the hose so that the amount of hose before the 90° turn is equal to the amount after the turn. Essentially you should have an equal length 90° elbow.
The outlet heater hose expands from 5/8” ID at the firewall end to 3/4" ID at the coolant pipe end. The hose at the coolant pipe end will snug further up the barbed end than the hose at the firewall end. Use two hose clamps on the hose-barbed end sections to secure the hose. I use ABA clamps which are smoothed metal (no holes) so the hose is not damaged.
John Deer present a table of visual symptoms you see in the clear plastic part of the tubing and what the potential problem may be as presented below.
I have had a John Deere Coolant Eye in my system for about six years. In that time about 1/8 to 1/4 of the dip tube has filled up with a very fine sediment that is almost powder like when dried after I drained it from the system.
After removing SHO engine heads at junk yards over the years, I’ve noticed that many of them have scaled or plugged coolant passages. Some of the engines are really abused as a lot of the coolant system is filled with a jelled like material (stop leak?). But even the ones that have immaculate oil pans, which would seem to indicate that the owner cared enough about the engine to keep the oil system very clean, had severe scale in the cooling passages.
Corrosion can be a severe problem in the SHO engine because it has aluminum heads but an iron block. Aluminum and iron are located at the extreme ends of the galvancic scale which means that corrosion is severe for iron when aluminum is present. That's why maintaining fresh coolant with an adequate level of anti-corrosion additives is so important for iron block/aluminum head engines.
I’m guessing here as I am no expert, but it seems to me that keeping the cooling passages as clear as possible is just as critical as supplying clean oil to the engine. After all blocked coolant passages would seem to cause hot spots on the heads and cylinders which would lead to all sorts of problems and reduced engine life – “cooking of the oil”, uneven heating of the cylinder heads leading to warping, leaking heads, ring damage??.
In any event the coolant eye only costs $15 to $20 and it seems like a low cost investment to keep the system clean of solids. It does get boring watching the coolant flow through the eye as if there are no problems with the system (bubbles, etc) as there are no visual clues that the coolant is moving as you look at the tube.
You can order the tube directly from John Deere at their site (www.deere.com) or at a John Deere parts store. I’ve only found one on-line store that sells it: www.keepingitgreen.com. They call the part at level gauge (LEVEL GAUG) and sell it for $17.95>
Coolant eye valve
• Helps identify potential problems before they can cause major failures.
• Easy-to-install device provides a window into your cooling system.
Will fit 5/8-in. or 3/4-in. hose openings.
• Excellent item for customers who want to save costly repairs that
result from cooling system problems.
• Provides visual inspection of coolant for diagnosis.
• Collects and allows for drainage of harmful deposits.
• Drain valve allows easy removal of coolant for analysis.
• Can be used as a flushing port.
Troubleshooting guide
Visual symptom, Potential problem, Potential danger
Air bubbles, Cracked head/gasket leak, Engine parts deterioration,
Low flow, Low coolant/obstruction/collapsed hose/bad pump, Engine overheating,
Metal particles, Aeration/low concentration of additives/electrical grounding, Eroded casting parts,
Rust/scale, Low additive concentration/unacceptable water, Thermostat failure,
Gelling, Over concentration of additives/incompatible antifreeze Poor quality water, Plugged system
Debris, Deteriorating gaskets/extra silicone, Corrosion/plugging
NOTE: All these potential dangers can cause overheating and eventual engine failure.
John Deere makes a device that is used mainly by owners of their tractors. The "coolant eye" (also called other names by parts sellers) is an extremely heavy walled clear plastic tube that is barbed on both ends to accommodate hose from 5/8" to 3/4" with a slanted dip tube. At the end of the tube is a valve for draining the tube and sediment that is captured by the tube. You can also attach a hose to the fitting on the tube to flush out the coolant system.
The coolant eye goes on the outlet of the heater hose – which is the hose on the right if you are standing in front of the car facing the engine. It is an extremely tight fit to locate the coolant eye at this location and almost impossible to access the drain valve fitting from either above or underneath the engine. But the solution is just to remove the tube to drain and flip it upside down to back flush. Minimal coolant will be lost from the system when you remove it to drain or back flush.
The molded outlet heater hose must be cut in two locations. The first cut is made as the hose exits the firewall and about one to two inches into the straight section after the hose makes its 120° turn to the straight section.
The next cut is made one to two inches before the hose makes the 90° turn to attach to the coolant pipe. This is the critical cut for you are not left with much hose at this end. Cut the hose so that the amount of hose before the 90° turn is equal to the amount after the turn. Essentially you should have an equal length 90° elbow.
The outlet heater hose expands from 5/8” ID at the firewall end to 3/4" ID at the coolant pipe end. The hose at the coolant pipe end will snug further up the barbed end than the hose at the firewall end. Use two hose clamps on the hose-barbed end sections to secure the hose. I use ABA clamps which are smoothed metal (no holes) so the hose is not damaged.
John Deer present a table of visual symptoms you see in the clear plastic part of the tubing and what the potential problem may be as presented below.
I have had a John Deere Coolant Eye in my system for about six years. In that time about 1/8 to 1/4 of the dip tube has filled up with a very fine sediment that is almost powder like when dried after I drained it from the system.
After removing SHO engine heads at junk yards over the years, I’ve noticed that many of them have scaled or plugged coolant passages. Some of the engines are really abused as a lot of the coolant system is filled with a jelled like material (stop leak?). But even the ones that have immaculate oil pans, which would seem to indicate that the owner cared enough about the engine to keep the oil system very clean, had severe scale in the cooling passages.
Corrosion can be a severe problem in the SHO engine because it has aluminum heads but an iron block. Aluminum and iron are located at the extreme ends of the galvancic scale which means that corrosion is severe for iron when aluminum is present. That's why maintaining fresh coolant with an adequate level of anti-corrosion additives is so important for iron block/aluminum head engines.
I’m guessing here as I am no expert, but it seems to me that keeping the cooling passages as clear as possible is just as critical as supplying clean oil to the engine. After all blocked coolant passages would seem to cause hot spots on the heads and cylinders which would lead to all sorts of problems and reduced engine life – “cooking of the oil”, uneven heating of the cylinder heads leading to warping, leaking heads, ring damage??.
In any event the coolant eye only costs $15 to $20 and it seems like a low cost investment to keep the system clean of solids. It does get boring watching the coolant flow through the eye as if there are no problems with the system (bubbles, etc) as there are no visual clues that the coolant is moving as you look at the tube.
You can order the tube directly from John Deere at their site (www.deere.com) or at a John Deere parts store. I’ve only found one on-line store that sells it: www.keepingitgreen.com. They call the part at level gauge (LEVEL GAUG) and sell it for $17.95>
Coolant eye valve
• Helps identify potential problems before they can cause major failures.
• Easy-to-install device provides a window into your cooling system.
Will fit 5/8-in. or 3/4-in. hose openings.
• Excellent item for customers who want to save costly repairs that
result from cooling system problems.
• Provides visual inspection of coolant for diagnosis.
• Collects and allows for drainage of harmful deposits.
• Drain valve allows easy removal of coolant for analysis.
• Can be used as a flushing port.
Troubleshooting guide
Visual symptom, Potential problem, Potential danger
Air bubbles, Cracked head/gasket leak, Engine parts deterioration,
Low flow, Low coolant/obstruction/collapsed hose/bad pump, Engine overheating,
Metal particles, Aeration/low concentration of additives/electrical grounding, Eroded casting parts,
Rust/scale, Low additive concentration/unacceptable water, Thermostat failure,
Gelling, Over concentration of additives/incompatible antifreeze Poor quality water, Plugged system
Debris, Deteriorating gaskets/extra silicone, Corrosion/plugging
NOTE: All these potential dangers can cause overheating and eventual engine failure.
