Replacing Valve Seals tomorrow, tips?

[xtreme80]

I've never done this before, so any tips would be helpful.

We're keeping the heads on the truck. Gonna use compressed air in the chambers to keep the valves up.

Do I just pull the old seals out with a pick, and push the new ones in? Should I pre-lube them? I'm doing all 16 so I wanna make sure I do it right.

I guess next question would be about how to adjust valve lash once I get it all back together? My dad doesn't use any special tools to do it, but he's been a tech for 30 years. I don't know if my lack of experience should require me to use special tools.

Any other tips and tricks are more than welcome, so I can get this done right the first time and drive my truck home tomorrow.

[Duro5341]

Slow and steady wins the race...

Put a coat of fresh oil on them, so they slide nicely.

When doing valve lash after initial tightning. Start engine, and tighten down all lifters just until they stop rattling. Then it's half a turn 180degrees after they stop making noise

Duro

[xtreme80]

Originally Posted by Duro5341

Slow and steady wins the race...

Put a coat of fresh oil on them, so they slide nicely.

When doing valve lash after initial tightning. Start engine, and tighten down all lifters just until they stop rattling. Then it's half a turn 180degrees after they stop making noise

Duro

That sounds just like how he used to do it. Thanks!

[Zoomad75]

Do yourself a favor and DON'T use the stock style o-ring seals. Fel-Pro makes an umbrella type seal to use instead of the crappy little o-rings. I changed mine a few months back (Too bad it didn't fix my oil consumption issue). I don't remember the part # but any compentent parts counter man should be able to look them up. I know I got mine at advanced auto and those guys can't normally find thier butt with both hands.

My dad taught me to put the piston up to TDC even though you are using air. This way if the air supply is interuppted and the valve falls, it can't drop all the way into the cylinder. That being said, DirtyLarry and I just hammered through one side at a time and never dropped one.

The only ones we had a hard time getting the spring compressor on was the #5 and #7 holes as the booster/master cylinder and firewall made for tight quarters to pry down with the compressor tool.

One last tip...Before you use the spring compressor, after you get the rocker off give the top of the spring a quick tap with a rubber mallet. Nothing hard, just a couple of quick taps to loosen up the keepers. Otherwise you might sit there fiddling with a small screwdriver in one hand picking out the keepers as you are prying down with the spring compressor with the other.

[xtreme80]

Originally Posted by Zoomad75

Do yourself a favor and DON'T use the stock style o-ring seals. Fel-Pro makes an umbrella type seal to use instead of the crappy little o-rings. I changed mine a few months back (Too bad it didn't fix my oil consumption issue). I don't remember the part # but any compentent parts counter man should be able to look them up. I know I got mine at advanced auto and those guys can't normally find thier butt with both hands.

My dad taught me to put the piston up to TDC even though you are using air. This way if the air supply is interuppted and the valve falls, it can't drop all the way into the cylinder. That being said, DirtyLarry and I just hammered through one side at a time and never dropped one.

The only ones we had a hard time getting the spring compressor on was the #5 and #7 holes as the booster/master cylinder and firewall made for tight quarters to pry down with the compressor tool.

One last tip...Before you use the spring compressor, after you get the rocker off give the top of the spring a quick tap with a rubber mallet. Nothing hard, just a couple of quick taps to loosen up the keepers. Otherwise you might sit there fiddling with a small screwdriver in one hand picking out the keepers as you are prying down with the spring compressor with the other.

Thanks for the tips. I didn't get the o-ring seals, I got some Comp neoprene umbrella seals.

And I plan on putting each piston to TDC anyways when I start working on that one.

I'll definately be using the rubber mallet as well too. Thank you.

[MylilBowTie]

You will want to return all the parts where you remove them. They wear together so if they are mixed up it can damage the parts and cause excessive wear. I would be a good time to check out the valve tips to see what kind of condition they are in.

I would set the valves cold then fine tune with it running. Depending on how much oil pressure you have its going to be a little messy or Exxon Valdez. It helps if you have an old valve cover with the center cut out to fine tune the valves running.

Turn the engine over by hand in the direction of its running rotation until the exhaust pushrod begins to move upward to open the valve. This ensures that the lifter is on the base circle, and the intake valve is ready to be adjusted. Tighten the adjusting nut until all the slack is taken out of the rocker arm and pushrod. By lightly turning the pushrod with your fingers as you tighten the adjusting nut, you will discover or feel a point at which there will be slight resistance. At this point, you have taken all the excess slack out of the pushrod. You are now at what we refer to as zero lash. Turn the adjusting one-half turn more. This will give you the ideal pre-load of the rocker arm, pushrod, and lifter. Following this procedure, carefully adjust all intake valves. To adjust exhaust valves, turn the engine over until the intake pushrod moves all the way up. Rotate past maximum lift, approximately one-half to two-thirds of the way back down. The lifter is now on the base circle and the exhaust valve can be adjusted. Rotate the exhaust pushrod with your fingers and begin to tighten the exhaust adjusting nut. When you feel the resistance on the pushrod, you are at zero lash. Tighten the adjusting nut one-half turn more. Go through the exhaust valves and repeat the procedure carefully. Now all of the valves are adjusted with the proper pre-load.

I slide the pushrod up and down to feel how tight its getting. I find that when I spin the pushrod to feel for the resistance it is too much. You can also check by picking up on the rocker arm where the valve tip goes. But you have to remove the 5/8 socket to check for slack. You want to tighten it down until all the lateral free play is gone. I work on one cylinder at a time so that I don't skip any. E is for exhaust and I is for intake.

[xtreme80]

Worst project ever.

That is a job I don't plan on doing again for a LONG time...!!!

I also think I'm the first one to ever turn valve seals into a two day project.

Turns out we didn't have the right fitting for the spark plug hole, so compressed air was a no-go. We took a piece of cotton rope and shoved it in there, then brought the piston to DTC on each cylinder to hold the valves up.

First piston, went ok, but when we backed the piston down, the rope got a knot in it and we couldn't pull it back out. Had to use a very small pick to untie the knot that somehow got in it.

Second problem is dropped a rocker nut into the lifter valley. Thought we were gonna have to pull the manifold to get it out. Ended up being able to use a mirror, a flashlight, and a magnet tool to get it out.

Third problem was that one of the keepers popped off the valve spring. Damn thing went flyin, looked for almost 45 minutes, couldn't find it. Ended up being able to pull one off my buddy's 84 Blazer project truck. I gotta remember to get him a couple new ones.

The bright side, is that the old seals on it were JUNK! All but about 5 of them were coming apart in there. So this should help with my oil consumption. All we have left to do is get the valves adjusted properly, and get everything put back together, but it's 1:30 in the morning and I didn't wanna finish tonight.

[Morgsie]

It's a much nicer job with the engine out, that's for sure. I spent a solid day doing mine. I cleaned everything in a varsol tank while my buddy took the springs off. One at a time, slow and steady, very frustrating but end result was worth it; no more blue on start up and oil consumption went down. I ended up using the o-ring style, buddy had a "spare" SBC gasket set that various gaskets/seals would be robbed from. I didn't know the umbrella ones were a direct replacement. Oh well!

[1975stepside]

Hey - WHAT sorta tool or fixture do you use to get the air-line screwed into the spark plug holes? And where do you get said fixture? Thanks!!

[xtreme80]

stepside, if you've ever seen the end of a compression tester, it would be something like that. The tester I have has a disconnect fitting, so I could, in theory, use the hose from my compression tester with the air hose from the compressor. The problem you run into though, especially with old engines, is that if the valves are warped at all, or not seated properly on the valve seats, you run the risk of dropping a valve anyways, and having to pull the head. That's why I used the rope.

Update for today is that I'm DONE with the project! We spent alot of time in the last couple days messin around with stupid crap, playin with my buddy's blazer project, and lookin for tiny parts we dropped. Had we not dropped so much, it may have been done last night.

To me this was the most fun I've ever had on a project. Hangin out at my buddy's backyard shop all weekend, workin on old trucks, and drinkin cold beer (after we were done for the night!) As much trouble as the project actually was, I'm still gonna help him do the seals on his blazer in a couple weeks. Should go much smoother next time around.

The plus side is, that there's no more smoke on startup, and no more smoke when I mash the throttle. It smells cleaner, looks to be burning cleaner, so it's a win win situation. Even if it didn't completely fix my problem, it definately helped.

[Ivan D.]

Yeah, I have to do that too, I didn't know about umbrella seals when rebuilding the engine so I just put stock o-rings back on, and of course it's burning oil. I plan on pulling the heads tho, much faster and easier this way, and less chance of messing stuff up. Besides I wanna do studs for the heads and also install new valve springs, so it's gonna be a perfect weekend project for when I overcome my laziness

[xtreme80]

If you're doing more head work like that, it's a good idea to pull the heads.

Umbrella seals basically just slide right over the top of the valve stem. Really no other way to do it. Easy stuff.