GM TSB consolidates liquid engine gaskets

[Paul Wright]

TSB # 05-06-01-010 for all GM models 2005 and prior.

GM consolidates liquid engine gasket sealers to TWO part numbers:
For gaps greater than 1.0mm (.040")
Adhesive General Purpose Gray 12346141

This sealant is to be used on all intake manifold end seals and all other applications where a gap to be sealed is 1.0mm or larger. The sealant is compatable with all synthetic, synthetic blends and mineral oils. The suggested bead size is 3.0mm (.120") +- .75mm(.030") without a groove, and a bead size of 4.5mm (.180") +- .75mm (.030") with a groove. The maximum working time of this sealant is 20 minutes. The sealant will be fully cured in 24 hours. The assembly may be filled with oil or coolant immediately after appying the sealant and torquing the bolts.

For gaps smaller than 1.0mm (.040")
Sealant, RTV 12378521

[Ron Slabaugh]

Could you clarify what the "groove" is? Also, this seems to explain why I can't seal up that 0.200+" end gap.

I think I'm going to try the aluminum plates suggested in a previous thread. I'll probably fasten them to the intake manifold in lieu of the block though.

[Paul Wright]

This TSB applies to ALL GM engines. Some engines have an RTV retention groove machined into the surface. It would look like an O-ring groove.

Yes, this implies that trying to seal 1/4" gaps is beyond the capabilities of the sealant.