Mistery coolant leak

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Jan 3, 2009 | 05:03 PM

geoaigel

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From: LA

Mistery coolant leak

The Excursion (2000 7.3 Diesel) dumped about a quart of coolant on the garage floor last night. Wife noticed when she drove back inside this morning after a short errand. The underside of the truck was still wet but I could not pinpoint the leak. It looks to be coming from the front of the engine (hoses, water pump, radiator). The truck got all new hoses about 2 years (30000 miles) ago.

I drove it up the mountain today to warm it up real good and stopped. Pressure built up fine in the system (hoses are nice and hard) and nothing is leaking out - not a drop.

Could the waterpump weep water depending on where it is stopped and then quit? I can not see a traditional hose or radiator leak plug up this quickly.

Any input would be greatly appreciated. For now we'll refill and watch the level closely. If I can not find this, I will replace all hoses, pressure test the radiator and replace the water pump just to be sure - that's a lot of work though if it is only one of the items on the list, especially considering that all the hoses are like new ...

Thanks!

George

Jan 4, 2009 | 03:14 AM

geoaigel

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From: LA

I just went back into the garage and it leaked again quite a bit - probably another 2/3 of a quart. I laid underneath and watched for a while. Drips are coming off the seam between the front of the oil pan and the block, right underneath the harmonic balancer.

I do not think that there is any water jackets behind the harmonic balancer. The flange behind the harmonic balancer is all wet. I can not find a wet spot on the bottom of the water pump with my hands (can't see anything!) but either the water pump or the water pump gasket can be the only source for the coolant.

Please if you can confirm that there is no coolant jackets anywhere below the water pump, that would be helpful. Looks like i have my work planned out then for tomorrow - new pump and gasket. 133k miles - not unreasonable for a new pump?

Thanks!

George

Jan 4, 2009 | 12:36 PM

UrbanXX

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This sounds like a water pump but bear in mind sometimes a small pin hole will develope in a hose or a radatior and "spray" toward an object and run down to the floor.
My first guess is a water pump, second guess a hose may need tightening or have a pin-hole in it. Also check the plastic radiator over fill jug for a small "crack or hole".

You should pressure test the system and under pressure one can usually spot the leak.

Check your oil for water in it and etc.

Best of luck and I do hope its something small and inexpensive.

Jan 4, 2009 | 03:53 PM

geoaigel

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From: LA

Waterpump is out. Nice clear track from the weep hole down, so I found the culprit. The pulley holder tool from the F-150 fit. Had to go buy a pipe wrench because my crescent wrench topped out at 1 3/4". Stuff coming out was green, so I will go with green for replacement.

Any input on the amount of anti cavitation additive? I have one quart to start me off - then I can test and refill as needed. I doubt I'll find the additive anywhere on a Sunday.

Thanks,

George

Jan 4, 2009 | 10:53 PM

geoaigel

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From: LA

Done and back together - no leaks after test drive.

4 quarts of additive to get started on the new fill - according to the owner's manual.

Thanks!

George