Click on image to zoom

GM/ACDelco Engine (RTV) Sealant/Silicone (2001-2018)

12378521 / 10-2010
Fits: 2001-2018 GM/Duramax
Pricing: $15.27


A one component room temperature vulcanizing (RTV) sealant. 5.3 Ounces Tube

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

Original production sealant used in GM engine plants; Recommended for all engine applications; Compatible with all synthetic, synthetic blend, and minerals oils as well as coolants including DEX-COOL; Special precautions: Surface should be free of residual fluids and also of detergent residues; Joints should be closed within 20 minutes of application; final tightening should be done within one hour of application and closure.


  • 12378521 / 10-2010
  • 12378521 / 10-2010
  • GM
  • New

Shipping Information

  • Item Requires Shipping
  • 0.5 lbs.
  • W5.0000” x H5.0000” x L5.0000”

Customer Reviews

Comment Total Reviews (0)

Write the First Review!

You must login to post a review.

  • Ask the Diesel Experts
  • 920-361-7700 Mon-Fri: 8am - 5pm (CST)
    Sat-Sun: Closed