First of all I would like to thank everyone that has posted their knowledge about hydraulic lash adjusters and how they work. I've been able to get this far by drawing from each person who has done this before.
One person said the lash plunger should move.
Another said it should not move until you push-to-release the check valve inside the lash adjuster body.
Someone else said their's would not move until they cleaned them in diesel.
One person said the plunger would move freely until the lash adjuster filled with oil.
So I built a simple test jig to test each lash adjuster, one at a time. The object was to put pressure on the top of the lash adjuster without covering up the hole on the top. I found a 3' length of aluminum flat stock in my junk pile and bent it in half to make the handle. Drilled a 1/2" hole in the tester base to locate the lash adjuster for testing. Then, using a small fender washer atop the lash adjuster, I could apply pressure on both sides of the washer while leaving the small hole accessible.
Dropped one lash adjuster in the hole at a time. Placed the small fender washer atop the adjuster. Started to push on the handle.
A small Allen wrench was perfect to press-to-release the check valve inside the lash adjuster. Started by testing all the lash adjusters from the *Other 2006 CRD*. Being the first time that engine had been opened, it provided a wide selection of totally worn out parts, worn-but-usable parts, and a few good parts.
I could easily press some hydraulic lash adjusters with my fingers, some were harder but still compressible, some were not compressible at all.
There is a second hole (above) in the test jig. This is for oil to supply the lash adjuster under test. There is a passage way from the big hole to the smaller hole that is not visible. This is to allow the lash adjuster to pump full of oil.
This picture (below) is tough to distinguish. It is the handle laying atop the washer atop the hydraulic adjuster. Also the small Allen wrench is setting inside the adjuster and standing up above the handle.
It didn't take long to determine that the good adjusters are the ones that could not be compressed until the Allen wrench was used to depress the check valve inside the adjuster body. Took a little feeling-around in the dark to locate the correct spot to press-to-open the check valve.
When the Allen wrench did press-to-open the check valve, then the plunger would collapse. It would also spring back up when pressure was released on the handle. It would compress and spring back several times until I released the Allen wrench. Then it would become solid again and UN-compressible when the check valve pressure was released.
Now, understanding how the good ones tested, I checked all of the lash adjusters from my Jeep. The bad news is they all tested good. This led me to the sobering conclusion that there is an oil delivery problem in the recently rebuilt head.
This could be caused by debris clogging the oil passageway, or the passageway had been welded closed when the machinist rebuilt the head and never re-drilled the passageway afterward.
I connected the remote starter button to the Jeep and cranked it over until oil started coming out. First it gushed out a passageway leading to the overhead cam shafts (now removed) in the head cover. So I mopped up the puddle and held a finger over that hole and continued cranking. As expected the first hydraulic lash bore for cylinder #1 started filling with oil. Installed that lash adjuster and continued - the second lash bore for cylinder #1 filled and overflowed. Installed that hydraulic lash adjuster.
Continued this way until cylinders 1, 2, and 3 intake adjuster bores were verified. That is where it stopped. #4 cylinder lash bores would not fill with oil.
Cleaned up the oily head and sat down for a beer. I now realize the head will have to come off and return it to the machinist to clear that oil passage.
I do, however, still have the head from the *Other 2006 CRD* that could be removed and refurbished.
Either way, this Jeep will not hit the road Monday.
Dean.