This is what I think the OP did since there was no oil inside the lifter. The lifters have a very light spring under the retainer and its easy to push past that tension and still rotate the pushrod.
On my 410 5.9 build, I took all 16 Hyd Roller lifters apart and emptied the light weight viz oil out and refilled them with 5W30. Made feeling that retainer move much easier.
