Loctite 37535 Dielectric Tune-Up Grease

This Loctite tube lays a moisture-proof silicone barrier on spark plug boots, trailer hitch connectors, and battery terminals, blocking salt, dirt, and water to stop pin oxidation and voltage leakage. A thin coat inside a boot or on connector pins takes under a minute. The standard 80ml tube works well for routine home service; apply sparingly to avoid flooding multi-pin connectors.

Best for anyone doing a spark plug service, maintaining trailer or tow-vehicle connectors, or protecting battery terminals in a wet climate. The tube format is cost-effective for multi-vehicle households. Skip it if you only need one connector's worth; a single-use packet from a generic brand costs less.

The 2025 SDS carries no GHS hazard classifications; the signal word is absent. A California Prop 65 listing appears in SDS §15, related to a substance in the formulation. Even so, SDS Section 8 calls for eye protection and chemical-resistant gloves, and Section 11 reports skin and eye irritation on contact, so goggles/glasses and gloves are recommended for handling. A respirator is only a situational precaution, for poorly-ventilated spaces or if the paste is applied near hot exhaust or manifold surfaces (heating above 300°F can release formaldehyde vapor per SDS §11).