Valve seals?

When changing valve seals and/or springs with heads on the car, compressed air is the way to go. BUT has any body tried putting the respective piston at top dead center and letting it catch the valve? How far will the valve drop? Will the spring be reinstall able? Basically will enough of the valve stem be accessible for the keepers to catch?
 
i know folks who have done that before, deff not recomended. i think it will drop a little too much to reinstall the spring without using a magnet to pull the valve up a little. dunno though as i've never done it that way and plan on keeping that streak alive.
 
Yeah I've done it

Been years ago but IIRC it was kinda like this.

You gotta make sure the pressure doesn't push the piston down the hole ...... make sure it stays up top.

It goes with saying the hardest part is getting the keepers to turn loose, lol.

You can put a big socket on the top and whack it if you find some of em stuck ...... and you will some like that for sure.

Good Luck

Grady
 
Grady: what about reinstall, did you just compress the spring, put it over the valve stem, install keepers and then let the spring pull the valve back up. Or do yo need to hold the valve all the way up with a magnet. I wasn't thinking taking them apart would be the hardest part?!
 
R.J. said:
Grady: what about reinstall, did you just compress the spring, put it over the valve stem, install keepers and then let the spring pull the valve back up. Or do yo need to hold the valve all the way up with a magnet. I wasn't thinking taking them apart would be the hardest part?!

What I remember was you had no prob compressing the spring but the keepers were locked tight to the stem on some of them. After a whack, then the keepers were loose and a magnet would get them.

Going back together was easier for me.

The air pressure kept the valve up.

The compressor was a lever type kinda thing if you know what I mean.

Grady
 
Yeah i did it on my stock heads, put pressure onthe cylidner compressed the spring and popped out the keeper, like grady said you gotta wack some of them cause they might be on there tough. I had the cylinder pressureized so the valves just stayed up. Im not sure if the piston would keep them up high enough for reainstallation. Are you talking about doing this without pressurizing the cylinder?
 
R.J. said:
I don't have a compressor, so I am looking onto my other options.
GRADY: what kind of "lever pump" are you talking about? Is it some kind of hand held pump? Maybe I don't need a compressor?

Sorry

I should have been more clear with my words.

The compressor I was talking about was for the valve spring. It is a lever that you put under the head of a blot screwed in the ped bolt hole. You hook the end of the lever under the bolt head and pry down on the spring to compress it. I think Summit has pics of the lever compressor IIRC. Think I've seen em at local parts places also.

This was on some E7's btw.

I now remember I killed the pressure on one hole and held the valve while slowly lowering it to see how far down it would drop and it went down just a small amount.

I have heard lots of the old time mechanics tell about putting the piston about half way in the hole on the rise and stuffing some small rope in to fill the space. They then move the piston to the top thus packing the now smaller space.

I have not tried that method but it does sound like it would work. :shrug:

Grady
 
I've seen (and tried) both above mentioned methods and they will work. If you're going the route with the piston (or rope) holding the valve up, make sure that the piston is where it needs to be (as high in the cylinder) as it will go before you remove the keepers on that valve. I know it goes without saying, but I'm saying it. If you drop the valve into the cylinder, the head will have to come off..... you get the point. I just wanted to say that because instead of taking a few hours to change seals, it might just take a few days to pull the intake, head, etc. After changing the first few seals, you'll get the hang of it and it will start going a lot faster. It's really not that hard of a job. Good Luck.

Phil
 
Given how close the piston comes to the valves, I'd say you could certainly use the piston to hold up the valves enough to do a spring remove/reinstall. Here is what worries me about this method, though -- if you have to use any real force getting the lock off, you're going to be applying pressure to the valve face unevenly, because it won't be resting flat against the piston, just along one side. Not sure how easy it would be to bend, but it wouldn't take much to ruin the seal.

Or maybe it's a non-issue. I worry too much ;).
Dave
 
Rootus said:
Given how close the piston comes to the valves, I'd say you could certainly use the piston to hold up the valves enough to do a spring remove/reinstall. Here is what worries me about this method, though -- if you have to use any real force getting the lock off, you're going to be applying pressure to the valve face unevenly, because it won't be resting flat against the piston, just along one side. Not sure how easy it would be to bend, but it wouldn't take much to ruin the seal.

Or maybe it's a non-issue. I worry too much ;).
Dave

Who would worry with a old set of iron 289 or iron E7 heads :rlaugh:

I know I did not :D

Don't think I wanna do that kind of stuff with my current heads :nono:

You do make valid points as far as I'm concerned :nice:

Grady