Bond It Gripbond Pro Max Adhesive - White EU3 
If you need a sealant that combines flexibility with heat resistance then the Soudal Silirub HT° - N is perfect for your needs. Silirub HT° - N has been brewed up by the chemists and engineers at Soudal.
Silirub HT° - N is based on silicone polymers. This allows it to be totally elastic even after it has been cured. In addition, it is temperature resistant up to 280°C, a truly astonishing amount in light of said elasticity. This makes it perfect for sealing in machines like engines and pumps which both have a lot of moving parts and produce a lot of heat.
It’s also neutral curing. This means that when it dries it only releases some alcohol, rather than acidic discharge found with some other sealants. On top of all of this, Silirub HT° - N is even free of MEKO. MEKO, or Methylethyl Ketone Oxime is a toxic substance often found in paints and sealants. It’s not found in Silirub HT° - N, however.
