Coolant leak

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May 31, 2009 | 07:51 PM

brown78

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Coolant leak

Just got a 78 2wd f150 w/351m about a week ago. I have fixed a brake issue, still have an exhaust issue. But what I want some advice advice on now is this:
Small puddle of coolant under truck, looks like it is leaking and hitting the starter before it is hitting the ground. the radiator hoses are fine, i don't see anything from above, and would probably need to remove the exhaust manifold to track it. What do you think???

May 31, 2009 | 08:06 PM

jeffsang

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connect a pressure tester in place of the radiator cap and pump it up to whatever is on the cap, 15-16lbs, and see where it is coming from. Remove whatever is necessary to find the leak

May 31, 2009 | 08:12 PM

montana_highboy

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From: Big Sky Country

Could be a leaky/rusty freeze plug, check for coolant around the freeze plug.

May 31, 2009 | 08:18 PM

brown78

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Thanks. I'll do that.

Jun 1, 2009 | 01:52 PM

sum_weirdo

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If it's hitting the starter this probably isn't it but being a 78 your rad might not have a rad overflow reservoir but rather a length of hose running from the cap neck down the side of the rad to the ground. Gotta love the 70s.

Jun 1, 2009 | 04:20 PM

brown78

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It's apparently leaking from the freeze plug. Now what can I do about that??????

Jun 1, 2009 | 04:33 PM

sum_weirdo

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Quote:

Originally Posted by brown78

It's apparently leaking from the freeze plug. Now what can I do about that??????

Not the end of the world. Drain the coolant, knock out the freeze plug with a hammer and punch (watch out there's gonna be more coolant in there) then clean the edges of the hole and tap in a new plug. Aim for the edges of the plug rather than the center, you don't want to push it into the cooling passage, once an edge is free grab it with pliers or something.

OR

For the super easy "probably work" approach throw some stop leak additive in there, it should seal that up pretty good.

Good luck.

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Jun 1, 2009 | 06:05 PM

SoCal76

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For pressing in the new plug, you may want to use a large socket that barely fits the inside diameter and a (gentle) hammer. Will keep you from bending it out of shape.