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-   -   Mysterious Coolant leak 4.7..... (http://www.jeepforum.com/forum/f310/mysterious-coolant-leak-4-7-a-1519931/)

Galaxie500LTD 05-07-2013 08:27 AM

Mysterious Coolant leak 4.7.....
 
1 Attachment(s)
I can't figure this out.. help.

I replaced my rad about 6 months ago, did a major coolant flush and switched to HOAT Mopar.

In those 6 months, my level in the overflow bottle has gone down about 1/4 inch... maybe? Yet when I went to change my oil last week, I noticed two very small pink drips on the bottom of my oil filter...

I checked the upper rad hose, bleed plug, rad, everything... I can find no evidence of a leak whatsoever. I wiped it down, drove around and went underneath the Jeep after about 20 mins on the HWY. Those tiny drips were back on the oil filter....

I wiped it down again, then went underneath with the motor running at operating temp and spent some time under there with a flashlight.... nothing.

I let it sit overnight, and just went under there again... nothing.

Does anyone have an idea where it's coming from?

:confused:

My flash whited out the colour and one of the drips (I'll take a better pic next time), but the circled area is where they appear...

Attachment 623638

AndyL 05-07-2013 09:10 AM

waterpump? weephole?

Galaxie500LTD 05-07-2013 09:18 AM

Quote:

Originally Posted by AndyL (Post 15400351)
waterpump? weephole?

Oops, yep, forgot to add that there is nothing coming from the weep hole. I had the belt off and checked for play or anything strange with the waterpump. Spun smooth and seems fine to me.

metalhead 05-07-2013 11:24 AM

Pressure test the system. That will tell you where the leak is.

Galaxie500LTD 05-07-2013 12:27 PM

Quote:

Originally Posted by metalhead (Post 15400909)
Pressure test the system. That will tell you where the leak is.

Ahhhh yes, I've never had to, or done that before. Just looked it up on YouTube, looks pretty simple. I'm out in the boonies so I'll have to see if I can get the tool or borrow one from somewhere eventually.... but if anyone has had the same leak show up, feel free to post what they found. Thanks all.

STORM_JK 05-07-2013 07:09 PM

Quote:

Originally Posted by metalhead (Post 15400909)
Pressure test the system. That will tell you where the leak is.

X2 its your best bet, either coolant will start dripping out or you'll hear the leak

Galaxie500LTD 05-07-2013 08:02 PM

Quote:

Originally Posted by NorthernWJ (Post 15403107)
X2 its your best bet, either coolant will start dripping out or you'll hear the leak

I hope so.... it's so F'd, I drove around a bunch today, got underneath and.... NOTHING... no drip, nada... dry as a bone....

It took 6 months for the level in the reservoir to drop so insignificantly I can hardly tell it's down.... ah well, I'll keep looking and try to get that tester.

Galaxie500LTD 05-21-2013 06:56 PM

Well I bought a pressure tester. My old rad cap was 21 lbs, I bought a new one that's 20 lbs... guy at the parts shop said that's what was called for in the 4.7

I put that cap on about 4 months ago, does it matter that it's 1 lb less than the old one?

Anyway, what pressure should I test at? 20lbs?

metalhead 05-22-2013 08:55 AM

pump up the tester to 20lbs and look for leaks.

Galaxie500LTD 05-31-2013 11:01 AM

1 Attachment(s)
AHA! I guess being obsessed with the well being of my 4.7 has it merits. I'm pretty much under my Jeep after every trip I take to check things out.

Anyway, I left the pressure tester pumped up for 5 hrs and it never dropped pressure, BUT there was a miniscule leak at the top of the water pump and a bitty one at the bottom. Just enough that one single drip would form, go around to the bottom of crankshaft damper... then fling over to my oil filter on start up... bingo. Water pump gasket. That would explain why after 6 months my reservoir dropped only a miniscule amount.

I plan on removing my alternator to make getting the pump off easier. There's also this bolt that sticks out between the AC compressor and the alternator... can I remove it too?

65Mustangs 05-31-2013 11:25 AM

Quote:

Originally Posted by Galaxie500LTD
I plan on removing my alternator to make getting the pump off easier. There's also this bolt that sticks out between the AC compressor and the alternator... can I remove it too?

That stud is part of the bolt pattern that holds on the timing chain cover (as well as a couple of the water pump bolts). You can remove it, but if I recall correctly you should use thread sealer on it when you put it back. It gets tightened to 40 ftlbs.

When I did my rebuild, I put sealer on all the bolts for the water pump and timing cover just because I had it, and it doesn't hurt. ;)

Good Luck!

Galaxie500LTD 06-02-2013 09:28 PM

Quote:

Originally Posted by 65Mustangs (Post 15503131)
That stud is part of the bolt pattern that holds on the timing chain cover (as well as a couple of the water pump bolts). You can remove it, but if I recall correctly you should use thread sealer on it when you put it back. It gets tightened to 40 ftlbs.

When I did my rebuild, I put sealer on all the bolts for the water pump and timing cover just because I had it, and it doesn't hurt. ;)

Good Luck!

Thanks man!

PS I've got a 66 Ford Galaxie. Those old Fords are TOUGH. My old 390 purrs like a kitten.. but can also GROWL when I want it too :D:D:D

Turbozcs2003 06-04-2013 08:25 AM

How many miles on your 4.7 and have you ever done the water pump?

Ah, the old FE Ford big block, had a 360 in a 69 Ford F100. Slapped a 4 barrel manifold with a Holley 750CM double pumper and headers on it.



Quote:

Originally Posted by Galaxie500LTD (Post 15512152)
Thanks man!

PS I've got a 66 Ford Galaxie. Those old Fords are TOUGH. My old 390 purrs like a kitten.. but can also GROWL when I want it too :D:D:D



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