Changing Valve Stem Seals

[KFH]

Can the valve stem seals be changed without removing the head?  I have borrowed a too that I can compress the valve seals with however the way it operated there is no way it is possible to get the leverage action on at least the last two or three valves as the fire wall is in the way. I tried on an old motor by feeding compressed air into the cylinder to prevent the valve dropping down onto the piston however the valve goes down with the spring probably due to the tightness of the collets.  Any suggestions on how to remove the springs in position would be appreciated.

Keith

[FCRB26]

By the time you took inlet and exhaust manifold off to hold the valves might be just easier to rip the head off the old girl and  do it on a bench pretty quick job compared to a new car.

[ACE]

G'day Keith,
To free up the valve collets you can get a socket that fits over the valve spring retainer and give the socket a couple of gentle hits with a hammer.Make sure the piston is down otherwise the valve may hit the piston.
Don't hit the socket too hard as the collets may jump off and you'll lose the valve in the cylinder and have to take the head off the motor.
I've done this quite a few times on various engines including grey motors with no problems.
Hope this helps,
ACE 

[fc4me]

Agree with Ace on this one but also before you do that make yourself another little tool. First get an old spark plug and brake all the porcelain off it leaving you with the threaded portion that screws into the head next get a male air line fitting and solder or braze the fitting into the top of the remaining spark plug.Then just get both valves closed, best at the bottom of the power stroke, screw it into the cylinder you want to change the seals on and hook up the air. be careful though if the piston isnt at bottom dead centre when you hook up the air it will probably turn the engine over a little. doing it this way there's no pulling manifolds or heads off because the air is holding both valves up and a lot less trouble. Hope it helps

[KFH]

Thanks all for the replies.  I have the adapter for feeding compressed air into the cylinder and will try the socket on the valve spring to release the collets.

Keith

[fc4me]

Let us know how you get on.

[sunnytim]

Agree with Ace on this one but also before you do that make yourself another little tool. First get an old spark plug and brake all the porcelain off it leaving you with the threaded portion that screws into the head next get a male air line fitting and solder or braze the fitting into the top of the remaining spark plug.Then just get both valves closed, best at the bottom of the power stroke, screw it into the cylinder you want to change the seals on and hook up the air. be careful though if the piston isnt at bottom dead centre when you hook up the air it will probably turn the engine over a little. doing it this way there's no pulling manifolds or heads off because the air is holding both valves up and a lot less trouble. Hope it helps

Yep done this heaps of times on greys with the compressor pumping up the cylinder up with a spark plug/air fitting.  It needs to be in 1st or reverse gear and chock the wheels as the pressure can turn the engine over.
As per the advice above to do this without any air pressure in the cylinder DON'T unless you like pulling the head off to get the valve out.  If you take the collets out there is nothing stopping the valve from going down into the cylinder  short of a bit of carbon or the like.
Tim