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12378521 - GM/AC Delco Vulcanizing RTV Engine Sealer - 5.3 Oz. (Half Caulking Tube) - GM Production Line Sealer

This product may require vehicle validation(s) for proper fitment. Please contact us to confirm correct vehicle fitment and usage.

Shipping: Can only ship UPS Ground in the continental USA
Pricing: $12.88


A one component room temperature vulcanizing (RTV) sealant.

A high viscosity product that cures when exposed to air. The cured material has superior adhesion and elongation properties and is very resistant to engine oils and coolants. It is also oxygen sensor safe and will not corrode metal surfaces. This is the original production engine sealant used in GM plants.

  • This sealant is to be used on any application where a gap to be sealed is less than 1.0 mm (.04")
  • This sealant is compatible with all synthetic, synthetic blend, and mineral oils and coolants including DEX-COOL
  • The assembly may be filled with oil or coolant immediately after applying the sealant and torquing the bolts
  • The maximum working time for this sealant is 20 minutes
  • Sealant will fully cure in 24 hours
  • Oxygen sensor safe
  • GM production line sealer

Surface needs to be clean and free of any residue or oils before application of sealer.

Click on the documents tab for the MSDS

Application List



Shipping Information

  • Item Requires Shipping
  • 1.0 lbs.
  • W2.0000” x H5.0000” x L2.0000”
  • Can only ship UPS Ground in the continental USA


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