Hydraulic Lifters Mopar
Here we have MOPAR lifters (1970)
In 99% of all cases hydraulic lifter "resurrection" can be achieved by simply disassembling those little rascals, removing the oil slag and debris, and reassembling them.
The procedure is very similar to the Mercedes W126 hydraulic lifters.
Remove the C-clip and simply remove one part after another. Submerge all parts in Diesel or WD40. Clean especially the ball and the ball seat VERY troughroughly. Ball and ball seat must be completely clean without any slag buildups or cakings.
Almost all hydraulic lifter failures have one common reason: Note the tiny spring; the task of this tiny spring is to press the ball against the ball seat. The ball / seat is a kind of valve; oil is able to enter the lower end chamber of the lifter and the ball seat prevents the oil from leaking out when the lifter is "loaded" by the pressure of the valve spring as soon as a cam lobe starts to actuate it.
If the ball or the seat is dirty, it won`t seal properly. Result: Hydraulic lifter collapses if actuated by the cam lobe and then this ugly clap-clap noise occurs.
I did this job multiple times and it worked in 100% of all cases. It will take you approx. 10 min per lifter.
Good luck !
And here we go: