I just finished an install of a Walbro fuel pump but I wasn't paying enough attention when I took the OEM unit apart. Specifically there is a formed rubber sleeve that goes around the pump outlet sealing it into the plastic fuel pump housing. The rubber sleeve can be installed in either of 2 ways, with the reduced ID up (away from the pump body) or with the reduced ID down (toward the pump body).

Which way is correct?

 

You need to make sure the smaller goes UP, into the hole of the housing unit.
Be carefull not to tear it!! I ripped mine, not much, like 1/2 of that upper ring (small ring) I would loose fuel pressure @ high boost. You can only get it as a set with the housing from the dealer!

 

Thanks,
Time to take it apart again.......