Just put a spankers Subaru one on and it's blowing very slightly. Will it seal when it heats up or do I need some sealer?

Cheers chaps

 

Shouldnt leak at all. Doubt it will seal. Ive never had a problem sealing them. Although i found putting a washer or two on before the nut to butt up against the spring helps to put a little more tension on the springs

 

Cheers bud. Brand new bolts and springs too. I'll try some washers.