headed-ws6

iTrader: (34)

Im changing the valve seals and was wondering how you keep the valve from falling? I was told that I could use a compression tester and that would be okay? If so would I go through like im doing a compression test and do one piston at a time? Any help would be awesome.

Thanks, Derek

GregWS6&z28

iTrader: (8)

get air into the cylinder, or use something like rope to crank down on so the valve doesnt fall.. thats what I used. do one cylinder at a time.

headed-ws6

iTrader: (34)

wouldnt using a compression tool get air into the cylinder?

GregWS6&z28

iTrader: (8)

usually a compressor with a spark plug fitting.

brad8266

iTrader: (23)

yeah use a compression tester line with compressed air attached to it instead of a gauge. The compressed air will hold the valves up. Swap out those 2 and move on to the next cylinders valves.

headed-ws6

iTrader: (34)

Okay where wopuld I get the compressed air from? Like an air compressor?

brad8266

iTrader: (23)

lol, yes.

headed-ws6

iTrader: (34)

lol well That posses a problem um where can i get one and how much would one cost I only need to it this one time.

brad8266

iTrader: (23)

You can probably get a cheap one from lowes/home depot or sears. They are good to have around the house anyway. Not a bad investment.

Or you might be able to borrow one from one of the 1,000,000 F-body owners in the DFW area.

headed-ws6

iTrader: (34)

Haha yeah lol. I think ill rent one for the day how long does changing the valve seals take?

GuitsBoy

iTrader: (4)

i never trusted the compressed air method. I prefer to use the TDC method. You just need to find when the piston gets to TDC using something in the number 1 cylinder spark plug hole. Once you know cyl 1 TDC, you can follow the method from the ls1howto cam swap article. mark the pulley with a sticker or something so you can keep track of your crank angle.

02 BLK WS6

iTrader: (11)

Just a little information. While trouble shooting a burned valve, I hooked and air compressor up to find if it would go through the intake, blowby the piston, or out the exhaust. Cylinder #1 went through the exhaust and cylinder #3 pushed the piston back down and started blowing through the intake. #1 and #3 had the burned plugs...

Moral of my experience is that if you used the compressed air method, you have to use a tool to keep the engine from rotating..

brad8266

iTrader: (23)

Not if you turn the pressure down some.

Rambo06

iTrader: (6)

First things first brad8266 seems to know his ****, as for the renting of the compressor you could go to walmart and buy a 20.00 air tank and have there service department fill it and theres your air cheap.

vettenuts

iTrader: (4)

If you ever had a valve leak an drop you wouldn't be very happy with using compressed air. For this type of job, I would use TDC or get a 1/8" braided nylon rope, remove all the rockers then one cylinder at a time as the piston nears the top feed in the rope through the spark plug hole. Gently rotate until the piston stops and the rope is squished against the valves. Now do your work on that cylinder. Once done, rotate the motor backwards, remove rope and move to the next cylinder. I've done this many times and there are no worries about a dropped valve.

brad8266

iTrader: (23)

I think if your valves are leaking that much to where 100 lbs of air is applied and a valve drops then you should probably be pulling the heads off for a valve job too because those valves or seats are jacked up.

But yeah using the tdc method will work also.

95 Z28

iTrader: (21)

Just do the TDC method.

vettenuts

iTrader: (4)

Well, there was a compressor issue too but that was too much to type. Bottom line was I found myself looking at a 1/8" diameter hole where the valve was

headed-ws6

iTrader: (34)

ok took the intake off and there is oil in the intake side of the head. could this still be the seats?

brad8266

iTrader: (23)

That could be the PCV or valve stem seals.