could use some help, 2007 xl 2.3 has been idling high for about a week no cleaned iac, tb, checked for vacuum leaks. now after yesterday I am sure it is a vacuum leak, after being parked for about an hour on a small incline i went to run to the store and pushing in clutch with foot on brake truck started to roll brake pedel was hard as a rock once I started it vacuum came back to normal and pedal stopped truck if anyone has had this happen and could shed some light i would be thankful idle in between shifts and at idle would be from 1200 to 3000 rpm's

 

First eliminate the IAC Valve, after engine is warmed up let it idle and Unplugged the IAC Valve's connector, IAC Valve will close and idle should drop down to about 500rpms or engine may even stall, either is OK.
If idle stays high then it is a vacuum leak, and now is a good time to check for it.
Remove 1 vacuum hose at a time and put your finger over the intake port it came off of, if idle drops down to 500 then you found the leak, follow that hose.


Brake booster has a check valve, it is the part that the vacuum hose hooks up to on the booster, the "elbow".
Check valve allows the booster to hold vacuum pressure when engine is off or if engine should stall while driving, it usually allows 2 or 3 brake pedal pushes before vacuum is gone.
You can test that by starting engine then turning it off, test how many pedal pushes before it gets "hard" to push.
Also remember when you are parking on a hill many leave their foot on the brake pedal after shutting off the engine, so that counts as a pedal push and does drain the vacuum pressure.
So when you got back in to drive and pushed the pedal it may have already been drained, from parking.

 

thanks for info RonD will check now and get back to you

 

went out and warmed up engine unplugged IAC and idle only dropped to 800 then sky opened up and its pouring so I will look for vacuum leak at another time

 

after checking all possible hoses for vacuum leaks I have come up empty handed, although I have noticed that with IAC unpluged I do not get the hanging idle but as soon as you plug it back in and rev it it hangs so I am thinking IAC is bad

 

Yes, it is possible, but I would clean it first.

To check for vacuum leaks you first unplug the IAC Valve, like you said idle went down but only to 800.
Then remove one vacuum hose at a time from the intake and plug that port with your finger, if idle drops down then that hose(system) has the leak.

It could be a gasket leak but test the hoses first.