What's involved.....replacing valve stem seal without removing the head?

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Wayne

Wayne

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My Cruiser has 249K on it now and uses a quart of oil about every 500-700 miles. It has a few leaks (oil pump cover, rear upper oil pan arch), but nothing dripping. I get very light blue smoke occasionally on start up after it's sit for a week. The coolant has no oil in it and vice versa. I'm thinking the valve seals are hard and seeping oil past them.

What's the procedure for replacing the seals without pulling the head?
 
*remove throttle body (and upper intake if you need that much room)
*remove valve cover and cams, making sure to lock chain to cam and crank gears so it doesn't lose time
*use compressed air via adapter, or rope fed into combustion chamber via spark plug hole then crank turned to compress rope against valves to hold valves up/closed
*keep track of shims and buckets upon removal
*use tool to compress valve spring while removing keepers and springs
*pull valve seal and replace

If you used rope, turn crank back and pull rope out, move to next cylinder, repeat.
 
bloc, thanks a lot!
 
This isn't related but maybe it'll apply or get you on the right path. I just replaced the springs and seals on my vette without pulling the head. Not sure how it'd work on a cruiser but... I did have to pressurize each cylinder with air via a hose that screwed into the spark plug hole. That way, when you pull the locks the valves won't drop. Hopefully you'll get some feedback from someone who can tell you cruiser specific info though.

I've seen this tool used on a Toyota head before. Amazon.com: Lisle 36050 Valve Keeper Remover and Installer Kit: Automotive

Here is a video of it being used. Skip to 4:45.

Just wanted to share!
 
dylans, thanks for the info and video.
 
i'd like to second bloc, i have used the rope trick quite a few times. Piece of advice if you do go that route, use quite a bit of rope so the valve doesnt sag. First time i did it, i didnt pack enough rope in the chamber and the valve fell about 1/16th of a inch and i had a bitch of a time getting it back up high enough to reassemble.
 
The rope trick has served me well over the years and like rory says- use a lot of rope. One thing to note- even if you zip tie your timing chain, check your timing before you fire it up.
 
Thanks Mud brothers for all the procedures and tips. I'll use the rope trick for sure if I tackle this job. Thanks again.

When turning the crank to compress the rope up against the valves how far does the crank usually turn? Does each piston have to be taken to the top of the stroke or do you just feed enough rope into the cylinder that not much travel/rotation is needed?

What type, diameter and length rope is recommended?
 
Last edited:
Bump for an answer to my above questions.
 
The more rope you put in, the less the piston has to travel. I used a ton of 550 cord, but that's because i had a couple hundred feet of it laying around.
Just use whatever fits in the hole, and keep putting it in until you can't turn the crank past top dead center.
 
Mandrake, thanks for your reply.
 
Wayne, Drake is right. I used paracord because I had a lot laying around. I like to feed enough rope that the piston is roughly 3/4 to tdc. That leaves enough play in case one of your valves falls a little, you have room to crank down more. I wouldn't recommend popping a valve loose with the piston at tdc, no room for error.
 
I do compressed air when I do this job. I have a compression tester and I install a air fitting on one end and screw the hose into the spark plug hole.

The cylinder MUST be on the COMPRESSION stroke for this to work so the cam is essentially NOT touching the valves.

It is a 4-stroke engine and the firing order is 1-5-3-6-2-4.
All 6 cylinders will fire in 2 full revolutions of the crank.
360° x 2 = 720°.
720°/6=120°.
Start at TDC on #1.
Rotate 120° to cylinder #5
Rotate 120° to cylinder #3
and so on.......

Now that I think about it........the cams will be out (sorry I work on Chevy's and Studebakers........)

@bloc :can you work from front to back cylinder to cylinder? Not rotate the engine at all other than to compress the rope?
 
RocketCityCrzrs said:
@bilt, I'm not sure it will matter what order you go in. All valves will be closed since the rocker assy will be off. Or i might have misunderstood your comment
Click to expand...

No, you got it. That's what I'm thinking, too since the cams will be out.

I prefer the air method because it's faster. You just have to smack the springs and retainers first with a soft-faced hammer in order to break the "stuck' part before you try to pull the keepers. If you wait, you MAY break the air seal and drop the valve. That's where I rotate the engine so the piston is near TDC on that cylinder so I can recover the valve with a magnet thru the guide if needed.
 
Are the valves even short enough to disappear through the guide if the piston is at TDC?

And aren't they stainless? If so, some alloy that is still ferrous enough for a magnet to work?
 
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