supersix

iTrader: (12)

Ok so I am changing valve springs on a friends car last night and it doesn't seem like the air hose fitting is totally secure in the sprak plug hole...I can feel a small amount of air excaping around the fitting...Then when I start to decompress the spring there is a sudden change in volume of the air excaping and the compressor kicks back on. I am scared to continue because I think the vavle is opening and I don't want to drop a vavle. I stoped for the night and decided to continue this morning...Any ideas as to why there is a sudden change in noise?

PREDATOR-Z

I will say this again.

DO THE TDC METHOD.

No tools needed, no air, no valves dropping (well just a little but they will be held by piston at TDC)

supersix

iTrader: (12)

I'm by myself in the garage how would I set the piston at tdc?

Var

iTrader: (1)

How many psi of air are you using? Maybe the valve is getting pushed down with the spring cause not enough opposite pressure in the cylinder. Also make sure the car is in neutral. If you have your manifolds off at the moment, the air you are feeling could be coming from the exhaust ports. If not then nevermind.

supersix

iTrader: (12)

The car is in neutral...Also it was the air hose fitting....I went and got the correct adapter and everything should be a piece of cake now.

Krab

iTrader: (28)

The air you hear when you're compressing the spring is because you're pushing the valve down with the spring. You have to tap the retainer (only retainer, not the locks) a little to get the locks loose, then retry and you shouldn't hear the extra hissing. Use a screwdriver and a hammer to tap the retainer. I'd heed predator-z's advice and use the TDC method. You can find a description here:
www.ls1howto.com
Just click on the F-body cam/valvespring swap and scroll down to the part where he changes the springs. The TDC method is safer than the air compressor. If you don't have a high volume compressor, it will have to start up after the air leak you have has depleted the tank, and could heat up to the point that it will just stop compressing air until it cools down. This would really suck when you have the old spring out and just getting ready to install the new spring and the air compressor fails.

davered00ss

iTrader: (4)

Check out ls1howto.com and read the cam install guid. They explain how to do TDC method. You can do that and use the air hose as a double safety.

618HAWK

iTrader: (361)

Not to question you, but once you put air in the cylinder wont the piston to want to go to the bottom. Unless less you do this in gear, M6 only of course