2004+ Fuel Filter W / Adapter Kit - Ultra RV Products W8006889 - 2004+ Fuel Filter W / Adapter Kit - Workhorse Parts. Part # W8006889 Description: This kit changes the fuel filter to a two outlet fuel filter instead of three outlet fuel filter. Kit includes (1) fuel filter and (1) adapter fitting. Ultra RV Products is a Division of Brazel's RV Performance workhorse fuel filter | eBay Find great deals on eBay for workhorse fuel filter. Shop with confidence. Skip to main content. eBay Logo: Workhorse RV Fuel Filter With Adapter W8006889 W0004996. Brand New. 4.5 out of 5 stars. 3 product ratings - Workhorse RV Fuel Filter With Adapter W8006889 W0004996. $70. Buy It Now.