LLC leak from head gasket

Engine, Transmission and related drivetrain.
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PMCS Rally
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LLC leak from head gasket

Post by PMCS Rally »

I assembled A87 L18 engine and installed it four years ago with LLC filled. But then, right before firing the engine I had a health issue and left my project for few years.

I did not notice back then but there was a minor LLC leak on the floor. I started working on it and last year finally I fired up the engine which is running perfectly and beautifully. But when it cooled down, I noticed small leak from both sides of the head. No leak inside cylinder or oil pan.

When I built the engine I did not check warpage, hoping all was well. I tried retorque head bolts from 40 ftlbs to 50+ ftlbs but it showed little improvement.

I am ready to remove the head and start over but before doing that I would like experts' inputs on what else to look for.

Thank you in advance.
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510rob
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Re: LLC leak from head gasket

Post by 510rob »

what does LLC refer to?
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James
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Re: LLC leak from head gasket

Post by James »

Do you remember if you torqued from the center of the head out?
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okayfine
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Re: LLC leak from head gasket

Post by okayfine »

PMCS Rally wrote:When I built the engine I did not check warpage, hoping all was well.
This would have been key, unless the head had history by you without issue.

What HG did you use? And echoing James' question regarding tightening specs?
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defdes
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Re: LLC leak from head gasket

Post by defdes »

510rob wrote:what does LLC refer to?
Lots and Lots of Coolant?
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Re: LLC leak from head gasket

Post by datzenmike »

My guess is Long Life Coolant.

Gasket will need changing at a minimum. Check head and block for warp. Maximum allowable is 0.004" across the full length using a straight edge.

Tightening sequence is...

RAD
7...8
3...4
1...2
5...6
9..10

Use this sequence and bring all bolts to 20 lbs, then
Use this sequence and bring all bolts to 40 lbs, then
Use this sequence and bring all bolts to 60 lbs

Head and block surfaces must be cleaner than clean! Spotless! Threaded holes cleaned thoroughly right to the bottom. Bolts can be reused multiple times as long as clean and undamaged. Do NOT use gasket sealers or dressings.
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PMCS Rally
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Re: LLC leak from head gasket

Post by PMCS Rally »

Thank you all for inputs.

I just realized that AF/LLC was JIS terminology only.

Yes, I followed torque order and procedure up to and from 39.8 ftlbs. It looks like the leak is from warpage or not-cleaned-enough surface. I will remove the head to check warpage and surface hoping the block is OK.

Does anyone have a dimension of Datsun Special Too #ST17420001 to keep timing chain tensioner in place? I am thinking about making one with wood unless the block is bad.
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bertvorgon
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Re: LLC leak from head gasket

Post by bertvorgon »

Most of us make/made one from a hard wood. Drill a nice hole in the top, and use a good quality wire for pulling it out. You just tap it into place, with a reasonable wedge on the chain. I have used my block for over 35 years now.

make sure you use a hard wood, or, use plastic, something that is NOT going to shred when you pull it out and drop crap down the chain to the bottom.
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okayfine
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Re: LLC leak from head gasket

Post by okayfine »

Tensioner Block.jpg
Tensioner Block.jpg (290.03 KiB) Viewed 5676 times
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
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Re: LLC leak from head gasket

Post by Sealik »

Image
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okayfine
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Re: LLC leak from head gasket

Post by okayfine »

Genius.

The page I posted should be 1:1, so it could be printed, cut, and traced. That's what I did when I made my tool.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
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Mattndew76
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Re: LLC leak from head gasket

Post by Mattndew76 »

I could make some of these from UHMW plastic.
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okayfine
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Re: LLC leak from head gasket

Post by okayfine »

Billet, with I-beam construction!
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
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510wizard
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Re: LLC leak from head gasket

Post by 510wizard »

But, for $7.21, is it worth even turning the mill on?

http://ecx.images-amazon.com/images/I/31V0G12PR8L.jpg
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Mattndew76
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Re: LLC leak from head gasket

Post by Mattndew76 »

Hadn't seen those ha ha ha.

Not worth the mill time.
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