Pressurize cooling system

[tribal599]

In the Explorer/Mountaineer workshop manual it states as a caution:
do not pressurize the cooling system beyond 102 kPa (14.9 psi) and pump the cooling system to a maximum of 102 kPa (14.9 psi) and hold for two minutes. If the pressure drops within this time, inspect for leaks ad repair as necessary.

When I did the pressure test I did it too 16 psi instead (forgot what the maximum was) and within two minutes no pressure drop and no leaks. But at around the three minute mark I noticed the pressure began to drop and at the five minute mark I noticed small drops of coolant on the ground.

I've watched some YouTube videos of people pressurizing their systems anywhere from five minutes to overnight. So my question is since there was no pressure drop or coolant leaking within two minutes like the repair manual states did it technically passed? Thanks.

 

[koda2000]

The Explorer's radiator cap is rated for 16 PSI, so I don't see why pressurizing the cooling system to 16 PSI would be a problem. As far as why the pressure dropped after 5 minutes ??? but you have verified that you have a leak, or it would have held pressure, so that would be a fail.

The reason for performing a pressure test is to find small leaks, which are more likely to show up (and easier to find) on a cold engine. I assume you already knew you had a leak somewhere, as coolant must have been disappearing.

 

[tribal599]

The Explorer's radiator cap is rated for 16 PSI, so I don't see why pressurizing the cooling system to 16 PSI would be a problem. As far as why the pressure dropped after 5 minutes ??? but you have verified that you have a leak, or it would have held pressure, so that would be a fail.

The reason for performing a pressure test is to find small leaks, which are more likely to show up (and easier to find) on a cold engine. I assume you already knew you had a leak somewhere, as coolant must have been disappearing.

I did the test on the cold engine. If a shop mechanic went by what the repair manual said at the two minute mark with no pressure lost he would have disconnected the tester and called it a day.
I did had a leak before and it was the timing cover gasket that was shot. Replaced gasket and new water pump. But then this small leak showed itself only after going past the two minute.

 

[koda2000]

I'll tell you this, if it's just a small leak (which is apparently your case), go to the nearest auto parts store and purchase something called K-Seal. Remove enough coolant from your radiator to fit the whole bottle of K-Seal in it (8 Oz?) shake the heck out of the bottle and pour it in the radiator. Start the engine and let it run for about 30 minutes. No more leak.

It's considered a permanent fix, it will not hurt anything and remains in your cooling system to seal future leaks. K-Seal is the best stuff for cooling system leaks I've ever found. Unless you like spending your time chasing small leaks, use this stuff. It really works.

 

[tribal599]

I'll tell you this, if it's just a small leak (which is apparently your case), go to the nearest auto parts store and purchase something called K-Seal. Remove enough coolant from your radiator to fit the whole bottle of K-Seal in it (8 Oz?) shake the heck out of the bottle and pour it in the radiator. Start the engine and let it run for about 30 minutes. No more leak.

It's considered a permanent fix, it will not hurt anything and remains in your cooling system to seal future leaks. K-Seal is the best stuff for cooling system leaks I've ever found. Unless you like spending your time chasing small leaks, use this stuff. It really works.

Thanks I'll look into K Seal.

 

[shadowless127]

I'll tell you this, if it's just a small leak (which is apparently your case), go to the nearest auto parts store and purchase something called K-Seal. Remove enough coolant from your radiator to fit the whole bottle of K-Seal in it (8 Oz?) shake the heck out of the bottle and pour it in the radiator. Start the engine and let it run for about 30 minutes. No more leak.

It's considered a permanent fix, it will not hurt anything and remains in your cooling system to seal future leaks. K-Seal is the best stuff for cooling system leaks I've ever found. Unless you like spending your time chasing small leaks, use this stuff. It really works.

I second this. But only K-Seal. Stay away from that Barr's Stop Leak crap, at best it will last a month, at worst it will cause damage. I've heard varying results and none of them really positive (as I don't consider working for a month a positive result).

 

[C420sailor]

Can you isolate the source of the leak?

 

[tribal599]

Can you isolate the source of the leak?

I think it's coming from the water pump area but it's new with a new gasket. Not for sure though. I know I tightened the clamp on the hose at water pump side (lower rad hose).

 

[C420sailor]

I had a similar leak. It looked like the water pump, but same---new pump and gasket. Turns out it was the thermostat housing seeping at the cover/housing joint, running down the wire loom of the crankshaft position sensor (no ****), and dripping out the loom down near the harmonic balancer. When I replaced the housing, the entire valley was full of coolant. Worth checking.

 

[F16pilotjd]

Was just searching for help with cooling system and saw this thread. Started out with deterioration of heat valve. Replace it and hoses. Then thermostat and water pump. Then new top and bottom radiator hoses. Pressure blew them off. I installed 2 new clamps on each and then replaced thermostat housing. Temperature remains in normal level but when driving it sounds like a loud fan or engine reving noise. Lately, I have been manually transferring from cooling resivoir to radiator and it works for a few days and then I have to do it again. Replace radios cap? At a loss. Will try any ideas

 

[koda2000]

If your cooling system is blowing off the radiator hoses, not expanding and drawing coolant from the reservoir by itself, it means one of 3 things.

1. The hose to the reservoir is clogged (remove it from the radiator and see if you can blow through it).

2. Your radiator has a hole/leak in it.

3. You have the wrong pressure cap on the radiator. Most GenII Explorers use a 16 pound radiator cap.

The loud fan noise may mean a bad clutch fan.

 

[F16pilotjd]

Cleaning the resivoir tonight. Buying new cap and manual says 18-22# range. I have and will replace with 20# cap motor craft part 8100. Don't believe I have leak as no fluI'd is left in my driveway or garage. Thanks. You are very helpful!!!

 

[koda2000]

Cleaning the resivoir tonight. Buying new cap and manual says 18-22# range. I have and will replace with 20# cap motor craft part 8100. Don't believe I have leak as no fluI'd is left in my driveway or garage. Thanks. You are very helpful!!!

Use whatever pressure cap that your manual recommends for your 2007.

 

[Mart1n]

Was just searching for help with cooling system and saw this thread. Started out with deterioration of heat valve. Replace it and hoses. Then thermostat and water pump. Then new top and bottom radiator hoses. Pressure blew them off. I installed 2 new clamps on each and then replaced thermostat housing. Temperature remains in normal level but when driving it sounds like a loud fan or engine reving noise. Lately, I have been manually transferring from cooling resivoir to radiator and it works for a few days and then I have to do it again. Replace radios cap? At a loss. Will try any ideas

Hi, I have the same loud engine fan roaring. The clutch seems to work fine (it slows down if I unplug it), the truck is not overheating either. Did you get to find the solution to your loud fan?

Thanks

 

[F16pilotjd]

Yes, Seems I had very tinny holes in bottoms of radiator. So small that fluid would not make it to driveway. The coolant would not transfer back to radiator from expansion tank. Engine would run hot causing the fan to run in overdrive. At least that is my layman’s interpretation. Since changing the radiator I have had limited occurrences of the issue. Only climbing mountains in Ecuador at 13k feet. I keep reading this thread and pulling more and more good info from the experts in the field. Thanks all!