Slow coolant leak in 2007 Explorer 4.6L

[Diesel Tom]

My son had a front end collision recently which required a radiator replacement among a lot of other parts. I have a very small coolant leak that I haven't been able to locate yet. It looks like something is dripping on the fan and is getting slung around the fan shroud with more on the bottom side than on the top side.

I replaced the antifreeze with the proper yellow antifreeze.

Is this one of the cars which need stop leak tablets in the system on a regular basis?

It is not the leaking Y connection on the rear heater - I replaced that last year.

Thanks for your help. Tom

 

[Floordford]

Could be leaking from the upper plastic part of the radiator and under the reservoir. Or from the pinch seem of the upper part of the radiator.

A fact that all 06-10 explorer guys,should know is that our cooling systems run a higher pressure. Average systems run 13-16. Ours run 16-20. So cheap radiators leak because they are not up to the job.

 

[Diesel Tom]

I was aware of the higher cap pressure. The original cap was rated at 20 PSI while the replacement was rated at 18 PSI. Do you think that some of the Ford specified stop leak tablets (WSS-M99B37-B6) would help? The leak is more of a seepage than a big leak.

 

[Floordford]

Well id drive it for 15min and get it warmed up and heat soaked and precisely locate the leak. Bandaid solutions are no good. You are just putting the problem off till later.

 

[wharriso]

Years ago I learned my lesson for using anti-leak solvents to stop radiator leaks. They often clog the thermostat and you will soon have an overheating problem, which is much worse to deal with than a small leak. Be patient. You'll find it.

 

[Fire488]

Have you tried pressure testing the system? I had a leak some years ago with mine and it drove me nuts because I could not locate it. I own a pressure tester, but it was lent out at the time. After trying everything I could think of I finally went and got my pressure tester. I set it to around 15 psi for 30 mins and could not find a leak. I pumped the pressure to 18 psi and same thing. Set it to 20 psi and lo and behold the radiator leaked at the plastic fittings near the top. I did have to replace the radiator. I did the tests cold. I did try again by heating up the engine to operating temp and then carefully repeated the pressure test. When I hit 10 psi it started leaking.
Good luck and be careful.

 

[curlymurt]

I recently had some coolant leak that was flung all over from the fan... for me, it was the water pump. From under the engine, I could see antifreeze staining on the front of the engine block where it had been leaking down from behind a pulley.

 

[centex99]

My slow leak was the crazy ass Y x 5 or whatever cable for the heater core. I wish I had read more on the forum and thought about just trying to fix it, but I had it replaced (part was expensive at like 200-300$ if I recall).

 

[Joey Threesticks]

Agreed with performing a pressure test if you are able. I've also had luck using UV dyes in my coolant to locate nuisance leaks and loose fittings.