I'm having trouble getting them pumped up hard. I only managed to get one to harden. If I put them back in the lifter bore and prime the oil pump with a drill will they then pump up hard?
The shop manual explains the only procedure that is sure to remove all of the air in a lifter with a pushrod seat that does not have a vent hole, like yours.
First, with the lifter disassembled you fill the lifter body with oil.
You then install the plunger with the hole in the body and plunger lined up. Then use a tool to keep the check valve unseated(I use a WD40 spray tube). While keeping the check valve unseated you push down on the plunger until the hole in the body and the plunger line up.
At this point you install a pin/drill bit through the body hole into the plunger hole. This will hold the plunger down low enough that the pushrod seat and snap ring can be reinstalled.
I then top off the oil in the plunger and install the pushrod seat and snap ring.
Once the snap ring is in place you remove the pin from the side to reactivate the lifter.
This is the steps that most people skip that give 235 hydraulic lifters a bad name.
I urge you to read my blog on this topic.
