Sealing Brake/Fuel Line clips

Any opinions on what to seal the brake line clips with in the transmission tunnel and fire wall. Mine had tarry substance or nothing at all. Butyl rubbber or urethane seems like a good choice.

3M Strip Caulk

https://www.3m.com/3M/en_US/p/d/b40068361/

I always have a box on hand and I use the stuff everywhere.

AMK sells mastic washers for this. They come in different sizes.

https://www.amkproducts.com/product/b-11445/

Thank you for the input. Would I use the mastic washers for the bolt on clips across the firewall and bits of the 3M strips on the two piece push in clips in the tunnel?

Not sure about the “bolt on” items your referring to. The clip goes thru the “strap” of the retainer, and the mastic washer goes on next.