Slimsilverado

iTrader: (5)

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?

joecar

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

Slimsilverado

iTrader: (5)

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

Burken01

iTrader: (88)

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

1FastBrick

iTrader: (16)

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.

Burken01

iTrader: (88)

Yes he's using gm mls gaskets!

1FastBrick

iTrader: (16)

This thread shows the notch I am referring to.

http://www.performancetrucks.net/for...5/#post5163178