Jeep Repair: Jeep evap, vent line, jeep wrangler

Question
QUESTION:
Hi Kevin,
There is a problem with my wife's 2000 Jeep Wrangler SE (2.5L Tech l-4). The problem is with the EVAP system.

The check engine light keeps coming on. When I check the code it is PO442 (small leak) and PO455 (large leak).

This started after I left the fuel cap off after filling up, the check engine light did not come on until days later, the first time.
I have cleared the codes, but they have come back after running for a few hours.

So far I have:
1: Pressurized the gas tank (less then 1 psi) through vent line at the evaporative canister.
And the pressure held after the air source was stopped.
2: Pressurized from where the vent line enters the evaporative canister through "leak detection pump" with the exit plugged, with no loss of air.
3: I have not smelled any gas fumes in the engine area or anywhere else.
My question is:
1:Where can I find information on the leak detection pump or how do I check it, electrically and mechanically?
2: Do you have any ideas on what could be the problem?

Any help would be greatly appreciated.

Thank you,
Roger
jumpomd@mindspring.com



ANSWER: U need to look at the lines for cracks first of all. U wont be able to see a leak  the hole size is .020 of an inch the size of a pin hole.

---------- FOLLOW-UP ----------

QUESTION: Hi Kevin,
I used soap water to check for leaks and also the pressure held over for over 30 minutes without a drop in pressure.
What do you suggest next?
Thank you,
Roger


Answer
how did U use pressure in a system that U yourself can not apply?  Plus pressure on a system is different then a leak to which vac is used. What lines have u inspected  look for cracks in the rubber tubes on the evap system from the intake back to the gas tank.