When I got my pads/shoes for our 88 Westy from PMB I did this procedure on the 91 Freeway at 3-4 am to avoid traffic, & this was with new rotors up front, & drums in back.
My guess is that the P4S Porterfields improved the notoriously under-braked Vanagon braking performance by 10-20%, but they still squeal on the front discs (rear are drums on these), & they are very dusty, so the wheels are always getting mucked up.
I got a set of P4S pads for my 85 BMW 325e too, but it's not ready for new pads/discs yet, so no experience there yet, nor on my 73 914-2.0 as it's not even close to done with the resto.
Would I use them again? .... not really sure on the Westy, the others I cannot say.
That procedure is meant to bed & mate the pads to a new set (or freshly turned & trued) set of discs, as Curt & others said above.
Tom
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