DropStop Dichtungs-Additiv

We Re-Seal Engines, Transmissions, and Rear Axles!

DropStop Sealing Additive

DropStop is a highly effective sealant additive, which is well suited for preventive use in vehicles and machinery older than 5 years.

DropStop is suitable for use in engine and gear oils. It is also usable in power steering systems. DropStop contains the necessary plasticizers (elastomers) for rubber seals in a highly concentrated form and supplies them to the sealing material. The rubber seals become soft again, swell and an existing oil loss is stopped.

For maximum effect, DropStop should remain in the oil for as long as possible. DropStop can also simultaneously be used with the oil additives MATHÉ Classic Motor Oil Additive, MATHY-M and MATHY-T. It is also suitable for motorcycles with an oil bath clutch.

DropStop is not suitable for seals made of packing material shaft seals made of graphitized ropes with asbestos, flat gaskets made of paper, cork or metal (e.g., cylinder head gaskets) as well as with cracked materials.

  • Oil loss is stopped
  • Seals become elastic again
  • Seal wear is stopped
  • Seals swell again
  • Expensive repairs are prevented
Price per liter: 115,80 €/l

Areas of application

DropStop can be used in all types of oil (mineral, partly or fully synthetic) and can be used in all oil feeding systems.

It can also be used in motorcycles with oil bath clutch, in vehicles with dripping shaft passages at the engine, transmission, and differential, as well as for oil loss due to brittle valve stem seals.

Units: Engine, transmission, differential, and power steering


Use DropStop with a mixing ratio of 1:16 (e.g., add 250 ml of DropStop to 4 l of engine oil). DropStop can be mixed with all engine, gearbox, and ATF oils.

It cannot be used in combination with MATHY-VS Viscosity Stabiliser.


The addition of DropStop can be made at any time. After adding, warm up the engine or machine. The full effect of DropStop takes time because seals / gaskets are made of very different materials. Many of them absorb DropStop very quickly, others may take up to 30 days to get the full effect.

MATHY DropStop

Sealing Additive

DropStop is available in our online shop in the following trading units:

  • 250 ml 
  • 3 x 250 ml 
  • 5 x 250 ml 
  • 12 x 250 ml
from 28,95 €

= 115,80 € / l

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