There is nothing quite like the feeling of walking out to your vehicle and seeing a mystery puddle underneath. This happened to me the other day. I love my F 150. I take good care of it and don’t beat on it. The hardest thing I ask it to do is sometimes haul a full load of gear for my job. So, it can be a little frustrating to see something like that.
My mind immediately jumps to bad and worst-case scenarios. I’m seeing dollar signs flash before my eyes for repairs that may cost more than a week’s worth of pay.
I get on the ground to see if I can determine what fluid is making the puddle and where it is escaping from. It’s engine coolant. The exhaust smells normal, and the oil is clean. I start to relax a little. However, from just looking, it is not clear where the leak is coming from. The only possibility I see is two small drips on one of the engine pulleys.
Time to do some research and figure out what is causing my 2015 F150 5.0 coolant leak.
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Research
It appears, this is a very common problem for Ford V8 engines made since 2011. The coolant leaks from the quick connect clamps in the T pipe that connects the upper radiator hose. More specifically, there is an O ring inside that hose.
The thing that makes it hard to find the leak is how it happens. It is a slow leak that happens when the engine is cold. When the engine gets up to temperature and the cooling system builds pressure, everything seals up. It does not leak when it is hot. But let the Ford V8 sit overnight, you will see the puddle from the coolant leak.
I do wonder why you need a quick connect clamp and O ring for a radiator hose. I guess someone got tired of spending endless seconds with a flat head screwdriver loosening hose clamps. Anyway, don’t put away that screwdriver quite yet. There’s no standard hose clamp, but you still need it to loosen the hose’s quick release clamp.
If you would like to watch a video of the complete repair, CLICK HERE! It will take you to the Project Cave’s YouTube channel. While there, make sure you subscribe.
Tools and Parts Needed
A bucket or other container to catch the coolant.
Slotted or flat head screwdriver.
A pick to assist in removing the old O rings.
Replacement O rings.
Some grease or petroleum jelly to grease the new ring.
Step By Step
- Step 1. Let the engine cool completely. NEVER open a hot radiator or coolant tank. NEVER!!! The engine cooling system is under pressure. If you open it while the engine is running or hot, coolant can begin to shoot out of the system uncontrollably. Many people have received severe burns opening a hot radiator. Again, let the engine cool completely.
- Step 2. Drain the coolant from your engine. I’ve seen some people pull the hose off and let the coolant go everywhere. Personally, I’m going to try and make the draining a clean job.
- Step 3. Remove the throttle body air intake. In case you are wondering, this is the pipe that leads from the air filter to the throttle body. Removing the air intake allows access to the part that is actually worked on. The “T” connector is right underneath it.
- Step 4. Using a flat head screwdriver, pry open the clip that is holding the quick release clamp in place.
- Step 5. Pull the upper radiator hose off the T pipe. Be gentle. Many shops and dealerships will have you replace the entire T connector assembly.
- Step 6. Remove the old O ring. The old ring will probably appear flattened out. Your new replacement ring will be rounded. If you are unsure about it, the O ring sits under the white plastic piece in the hose. You can use a pick to remove the ring.
Step 7. Spread a layer of grease on the new ring and place it in the hose. Put it in the same spot you pulled the old ring from.
Step 8. Slide the hose back onto the T pipe.
Step 9. Pop the clip back in place.
Step 10. Replace the air intake.
Step 11. Fill the coolant reservoir with coolant.
Step 12. Start and run the vehicle for a few minutes.
Step 13. Check the coolant level and add more until you reach the fill line.
Bonus Maintenance
This coolant leak doesn’t appear to happen to brand new engines. They seem to have 50,000 plus miles. Just a thought, while you are working in your cooling system, you might consider changing the engine’s thermostat. It is a simple part to replace. Disconnect a hose, pull the old thermostat, and drop the new one right in. You probably don’t need to do this right now, but since you’re there anyway…
The thermostat in the links is the exact one I used in my truck.
Wrapping It Up
Over the next couple of days, check under the vehicle to see if that leak is gone. Best time to check is first thing in the morning before you drive anywhere. Remember, if it is a leak from the bad O ring, it may only happen when the system is cold.
And I have good news! A few days after completing the repair, everything is fine. There are no more puddles happening overnight. The system is back in working order and holding the coolant. No more leaks!
