Renewing O-rings when they must be removed and replaced, will make doubly sure the seal is maintained. The old one may seem O.K, but heat and pressure after tightening, will make them brittle and hard. Use only OE seals for accurate fitting. Specify all the seals required in one order and save money on shipping costs with a multiple order.
To help you order the correct quantity and type of seals, gaskets and other consumables, why not check our online schematic, or if your machine is not supported this way, simply browse the product gallery; which will list everything you need for a successful overhaul.