PDE seals must be replaced during diesel engine overhaul: Background on reinforced VITON sealing rings
The operating principle of the 07eins reinforced VITON sealing rings for maintaining and repairing cylinder heads in Volkswagen Group TDI diesel engines with unit injectors (VW, Audi, Skoda and Seat) provides lasting prevention of future cylinder head damage, particularly when combined with the 07eins ORIGINAL PD injector retainers (repair retainers) or the 07eins ORIGINAL PD injector bridge. The oversize VITON seals from 07eins are the ideal complementary solution for preventing cylinder head damage in unit injector engines.
Technical background on the need to replace the old sealing rings and use 07eins reinforced VITON sealing rings:
Our mechanical systems for improving PD injector installation and positioning, such as 07eins PD injector retainers (repair retainers) and the 07eins PD injector bridge, provide the basis for technically sound injection function in TDI engines, even at very high engine mileages. The technical operating principle of the 07eins PD injector retainers is explained in detail in our blog post "Preventing cylinder head damage in TDI engines with unit injectors: optimal problem-solving with 07eins PD injector retainers".
The heavily stressed sealing rings on the unit injectors play an equally important role in improving the injection system and ensuring its reliable sealing. Under extreme temperature fluctuations, vibration and direct contact with fuel and engine oil, these seals must keep the pressurised diesel circuit separate from the oil circuit. If these seals fail, diesel mixes into the engine oil, causing oil dilution. Unnoticed, the oil rapidly loses its lubricating ability, which often leads to severe engine damage during continued operation. Without proper lubrication, crankshaft bearing shells, connecting rod bearings, camshafts, hydraulic tappets, the turbocharger's centre bearing and, not least, cylinder running surfaces, pistons and piston rings wear out in a very short time.
Why should unit injector seals be replaced when the injectors are removed?
After the PD injectors have been removed and re-centred, new seals restore an undeformed foundation for sealing. Ageing and uneven loading can leave old rings hardened or unevenly compressed. Replacing the appropriate seal sets is therefore part of a careful PD injector repair.
Why does 07eins use reinforced VITON seals?
The reinforced 07eins VITON seals combine a larger cross-section diameter with a lower Shore hardness. This allows them to fill the seal groove and achieve a larger contact area without relying solely on harder material. VITON belongs to the fluoroelastomers, also known as FKM or FPM, which resist fuel, oil and high temperatures. Choose the seal set that matches the type of PD injector fitted; a separate version is available for compatible 16V BOSCH PD injectors.
