Please bear with me, i done alot of reading and searching but i'm a little confused here, so help me out please .

I recently got hold of a 99 XJ with 147k on it and was thinking of doing some major build ($$$) but would like to make sure the overall condition of the Jeep before throwing in the $$$ thus these tests.

Here are the result of my compression test,

Here is a video of the leakdown test, with cylinder #1 at TDC (compression stroke, i double confirm with the marking on the harmonic balancer and the timing cover marking).
The only leak i detect is coming from the crankcase (no bubbles in radiatior, no hissing sound from exhaust, no hissing sound from intake manifold).

Here are some questions which i really appreciate if i can get some help,

1) With the low compression numbers i have, why is the leak % within the "low" range?

2) In the video, the % of leak went up when turn the crankshalf in an attempt to simulate when cylinder is NOT tdc but as i stop, the leak when down as if the engine was trying to seal up the leak.


I hope you are understanding me.

I tested my leakdown test kit with an air blower attachment to make sure is working and i was getting around 60% stable leak, therefore i conclude that there is nothing wrong with the kit.

Would really appreciate if someone can advise.
Thank you very much.

 

This is what i did,
1) Position Cylinder #1 to TDC (compression stroke)
2) Remove spark plug and insert Adapter Hose
3) Turn regulator **** on gauge until Leak gauge reads "0"
4) Connect gauge to Adapter Hose
doing these will give me a leak % right?

 

I could be wrong but if you cranked or turned the engine over wouldn't that have pumped thet cylinder back up?