One of the most common oil leaks in the 7.3L Ford Powerstroke stems from the turbo pedestal. The pedestal has 4 o-rings where oil can start to leak from. Oil leaks in this area could lead to turbocharger failure, engine damage, and even an engine fire. Even if these diesel o-rings aren't currently leaking, it is recommended that you replace them anytime you remove the turbocharger whether it be for upgrades or repairs. Be sure to remove and replace the lower pedestal o-rings whenever you're servicing the turbocharger to avoid the added time and cost of dealing with a pedestal leak down the road. The Sinister Diesel o-rings are constructed from a durable synthetic polymer called Viton, which meets SAE J200 standards for heat, aging and oil resistance. The o-ring design is precision molded to meet or exceed OEM standards, to keep your Powerstroke running properly. This kit comes with four diesel o-rings (two for the pedestal to the engine block and two for the turbo to the pedestal). Follow factory torque procedures for proper installation, which is 18 lb-ft to tighten the pedestal to the block and 35-37 lb-ft to tighten the turbo to the pedestal.