Coolant Leak

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Dec 6, 2005 | 04:54 PM

4X4 IN REFUGIO

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From: Refugio, Texas

Coolant Leak

Hey Guys... Got Something That Been A Little Frustrating To Me.

A Few Months Or So Ago I Replaced My Waterpump. (about 50,000k).
Anyway The Change Out Was Easy Enough But After Warming It Up And Test Driving It There Was A Very Small Leak At The Thermocouple Housing. I Had Not Bought A Housing But The Flat O Ring Was New.

Took The Housing Back Off ....cleaned It Up Again And Used A Little Bit Of Permatex Form A Gasket And Re-installed The Housing. This Fixed It...for A While.

About A Month Later Got Tired Of The Little Bubble Leaks That Had Come Back.... Went Down To Dealership And Bought A New Housing And A New Flat O Ring. Cleaned It Up And Installed...fixed.. No Leaks.

Now Today...bout A Month Later... Leaking Again (wheater Is Colder But Not Much )
So We Have New Water Pump... New Thermocouple Housing ... New Flat O Ring.... Torqued Down Properly And Evenly. Leaking.

Any Ideas ??????? Thanks To All

Dec 6, 2005 | 05:12 PM

CAT_man_963

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Joined: Feb 2004

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From: Elverson, PA

Umm... do you mean Thermostat housing by any chance??

Dec 6, 2005 | 05:54 PM

4X4 IN REFUGIO

Thread Starter

Elder User

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From: Refugio, Texas

Yes... The Thermostat Housing... Where It Bolts On Top Of The Waterpump.
Leaking From Inbetween The Pump And Housing

Dec 6, 2005 | 05:57 PM

4X4 IN REFUGIO

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From: Refugio, Texas

Now I Know Why You Asked Me This Question Cat Man.
Just Reviewing My Post And I See That I Had Been Thermocouple Instead Of Thermostat!!!!!!!!!!!!!! Don't Know Why I Did That..

Dec 7, 2005 | 07:44 AM

4X4 IN REFUGIO

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From: Refugio, Texas

More Info.... After Engine Warms Up ..... No Leaking
Seems To Leak A Little After Engine Has Cooled Down
Any Ideas
Use Permatex ?
Maybe A New Flat O Ring ?
Change Thermostat ( Still Has Original ) ?
Radiater Sealant ( Not A Good Idea ) ?

Dec 7, 2005 | 08:26 AM

Kwikkordead

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Joined: Jun 2004

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From: Rio Rico, AZ.

Quote:

Originally Posted by 4X4 IN REFUGIO

No Permatex! That will anchor the o-ring in place and prevent it from following the expansion and contraction of the flange. Use a thin coating of silicone grease, like the stuff that plumbers use for lubing faucets. Don't goob it up or the hydraulic pressures generated between the flange and the o-ring will cut the o-ring in two. Been there done that.

Just enough to make it look wet.
Suggest a slightly thicker o-ring if you can find it. I suspect something was not machined just right and it's not putting enough pressure on the o-ring to seal up good.
Yes get a new thermostat, can't hurt while it's apart again.
Avoid radiater sealant like the plague!

Last edited by Kwikkordead; Dec 7, 2005 at 08:28 AM.

Dec 7, 2005 | 01:28 PM

skibender

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Joined: Dec 2003

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From: Union Grove, Wisconsin

If replacing the thermostat, you might want to consider buying a 203 degree. When I did a search on replacing the waterpump on my truck, seemed like just about everyone recommended the hotter thermostat. Diesel's like to run hotter.
I agree with Kwik, the o'ring groove might be slightly large and not allowing a complete seal after the bolts are torqued down.