Correct psi.

[darnie1987]

Im going to be swapping the springs out with the heads on tomorrow i was just making sure what psi i nees to put into the cylinder to keep the valves from falling. Ive heard 90-100 psi? Wanto make sure before i mess anything up motors a 2004 5.3 lm7

[darnie1987]

bump... anyone have an idea?

[Frenchy]

just use whatever, damn. Enough to hold the valves shut.

[pl4yboy]

I prefer to roll the engine over where the piston on that cylinder is up. Much less scary.

[Ray@NP]

100psi will be fine nothing will happen

[Frenchy]

Anyone else want to bet they'll be another thread? What's wrong with my engine? I HEAR AIR LEAKING OUT!

[darnie1987]

Ok cool thanks ray, and ya i think thats what im gunna do Justian, appricate the help and ideas.

[RS/SS 4.8]

I prefer to roll the engine over where the piston on that cylinder is up. Much less scary.

Ha, tell me about it. I was so damn excited to put my cam in I forgot to put it tdc and with my small compressor and the leaking air, tank ran out pretty fast and dropped the valve. Got lucky and pulled it back up with a magnet.

[country_3030]

Can be hard to get it to stay at TDC once aired up. Have had my compressor turn the crank and put the piston at BDC before. Also have had the valve stem seal catch a valve once before. Got lucky on that one. I just hook my air hose up to the cylinder and make sure my compressor is over 100psi.

[darnie1987]

what i ended up doing was installing the spark plug tool, and turning over the crank. it would eather push air out or draw air in. once it wouldnt do neather i would put 100 psi to it and it would hold. so far i have gotten the passangers side all swapped out. thanks for the help guys.