head gasket sealing issue

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Nov 16, 2013 | 05:11 PM

Slimsilverado

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From: Cedar Park, Texas

head gasket sealing issue

New gm mls gaskets with arp head bolts. Driver side is sealed good but passenger side is leaking. Its dripping out toward the header. I gotta pull it apart and see what's up. Does anyone have suggestions on anything to help the seal?

Nov 16, 2013 | 06:36 PM

joecar

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From: So.Cal.

More info...
which block (new, old)...?
which heads (new, old, milled)...?
did you check the block and heads for flatness...?

Nov 16, 2013 | 06:43 PM

Slimsilverado

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From: Cedar Park, Texas

Stock ls1 block and heads. Did not check for flatness. Cleaned block and heads very well. 853 heads.

Nov 17, 2013 | 01:53 AM

Burken01

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From: Anaheim, Ca

Quote:

Originally Posted by Slimsilverado

Stock ls1 block and heads. Did not check for flatness. Cleaned block and heads very well. 853 heads.

High mileage heads?

You can always pull them (head gaskets) off and coat them with permatex copper spray..

But it's possible the heads are not 100% flat if they have a lot of miles

Nov 17, 2013 | 11:01 AM

1FastBrick

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From: JunkYard

Quote:

Originally Posted by Slimsilverado

Stock ls1 block and heads. Did not check for flatness. Cleaned block and heads very well. 853 heads.

Did you use MLS or Graphite Gaskets???

If you used MLS I bet the 853 head has a notch cast into it. If it does have a notch cast into it then you need to use Graphite Gaskets.

Some of the Gen 3 heads from 99-01 had a notch cast into them and require the use of the Graphite gasket. The MLS gasket will not seal on these heads. They will leak as soon as you fill them up.