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Discussion Starter #1
Today I changed by passenger side valve cover and I noticed many black broken plastic pieces, I have no idea where they come from, engine seems fine but clearly it came from some where. How can I know and verify?


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Sounds like they are broken valve stem seals, which get quite brittle after years of use.
Time for some replacements.
 

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The purpose of them is to restrict excessive oil from passing down the valve guides and entering into the combustion chambers.
The results would be some oil usage and oil burning especially at start up.
There is no danger with continuing to drive the car as it is.
 

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So is it a big job to change replace them?
Hey Mr. J,
Take the Valve Covers off.
Take the Rocker Assemblies off.
Take the OLD Valve Stem Seals off.
Put the NEW Valve Stem Seals on.
Replace the Rocker Assemblies.
Replace the Valve Covers.

JC
 

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They are under the valve spring retainers. You will need a valve spring compressor (Harbor Freight) and an old spark plug. Break the core out of the old plug and braze a male air fitting into it. Bring the cylinder you are doing up just past top dead center and take it down almost full stroke (You are on the power stroke with both valves closed). Put the modified spark plug in that cylinder and hook up your air hose to it. This will hold the valves in place so you can compress the valve springs and remove the keepers. Its a good idea to put some rags over everything except what you are working on, in case you drop a keeper, so it doesn't fall down a hole. Use a magnet pick up tool to pull them out once the spring is compressed. Release the tension and remove the retainer and spring. Remove any remnants of old seal, and slide on a new seal. Put a little oil on the valve stem before sliding it on. Reinstall the valve spring and retainer, compress the spring and put the two keepers back in place. Make sure the keepers are fully seated and slowly release the tension on the spring making sure the keepers stay in place. Wear safety glasses in case one pops out, so it doesn't hit you in the eye. After everything looks to be in place, give the top of the stem a smack with a plastic hammer to make sure everything seated properly. Disconnect the air hose, remove the modified plug and move on to the next cylinder and repeat. Obviously this is all after the VC removal and rocker arm removal mentioned previously. :)
 

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YES it is a large job.
Hey Gary,
You're Right. I don't know what I was thinking...

It's a little more convoluted than what JC said, but then again he's being funny! LOL
Actually, I wasn't trying to be funny, but I replaced the Valve Stem Seals in Lorrie, and I didn't remember all of what it took.

He could have "fine written" the instructions and you'd STILL be reading them an hour from now :)
Actually, it is a pretty good sized job. I probably shouldn't have even said anything, now that I think about it.

BUT after reading Agggilli's description of the task, maybe I can make up for my over-simplification of the job by telling Mr. J about the "Magic Rope Trick" which simplifies the whole process. It's what I used on Lorrie to do the job.

Whaddaya think?

JC
 

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Agggilli has described it rather well, but I'll add that the compressed air hose with spark plug threads can be used from a compression tester. Or, buy one, or get a free loaner from the auto parts store. Also, as you have removed the rockers anyway, don't worry about firing stroke or not, as it doesn't matter. When you apply your 100 psi the piston will stroke down to bottom-center all by itself. Use caution there, as the crank will obviously turn, including the fan, alternator, etc.

I'd also recommend either a magnetic tool, or a killer magnet stuck on needle-nose pliers to easily pluck the valve locks (split keepers) from the retainer. Plug every head drain and pushrod hole with paper toweling, as the dropped valve locks have a magic way of finding those holes. I throw a shop rag over the process just to prevent the occasional flying keepers from being lost.

Note here, that a push-type removal tool is both cheap and very fast when stock valve springs are the enemy. However, while easy on an engine stand, in the car can be a bear when trying to apply 80 pounds of force on it, or smacking it with a hammer. If you have the room to do it - this type is a winner. If not, valve spring compressors are usually used.

There are a number of valve spring compressors that will work, from cam-over tools to special FE-only versions, from $25 to nearly $100. I use the cam-over type a lot, as it fits almost every overhead-valve engine type. I do not suggest the type with a screw knob on top, as they will wear you out pretty fast. The job isn't hard - just tedious. Figure 1/2 to a full day for the first time, taking it careful and slow. And, don't forget to pull all your paper towel plugs.
:tup:
David
 

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Discussion Starter #14
David I recently purchased lisle air operated valve holder 19700 you mentioned I could buy and I also bought a 5605 Deluxe Compression Tester kit OTC, the good and bad the Lisle has a screw in type hose but my compressor tester has the pop in type connector. Good thing it came with hoses that will work so I will return the lisle. My question is since I'm not running air compressor but will be using compression tester, the instructions says crank engine for at least five compression strokes or until the pressure reading stops rising on the gauge. What do they mean?


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the instructions says crank engine for at least five compression strokes or until the pressure reading stops rising on the gauge. What do they mean?
exactly what they said...crank over engine enuff times to get the highest reading that cylinder will produce......when doing a compression test.... Not to hold/keep from dropping valve into cylinder

another trick that can be used to keep valve from falling into cylinder....
I am surprised JC didn't tell you how to use the "Magic rope trick" ...:)

drop a few feet of thin rope into cylinder, then turn crank, until piston press rope against valves....

remove and reinstall new seal spring and keepers.....
pull rope out,,,,done.....;)
 

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+1. For compression testing, I do this:

  • remove all spark plugs
  • disconnect the ignition coil (and electric fuel pump if it has one)
  • set throttle wide-open
  • crank several revolutions until reading no longer increases on each stroke (usually 4 to 6 revs)
  • write it down
  • move to next cylinder
  • if your battery weakens noticeably during the process, keep it boosted with a fast charger or jumped with another car.
Leak-down testing must be done with compressed air.

David
 

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Discussion Starter #17
Big Dave excuse my lack of grasp here I understand to do the leak down tester I use compression tester( cranks on engine give compressed air). What I'm missing is earlier u described I can use compression tester to change valve stem seals. There was mentioning of when I apply the 100 psi, so it seems there are two things going on and I mixed them up

1. If I want I want to do leak down for testing valve pressure I use the compression tester, that is very clear. If this way can be used to change seals please clarify.

2. My issue is broken valve stem seals , so I should use an air compressor with the Lisle valve holder and apply 100 psi to keep valve from falling and continue the process as mentioned in earlier post.


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Discussion Starter #18
Big Dave excuse my lack of grasp here I understand to do the leak down tester I use compression tester( cranks on engine give compressed air). What I'm missing is earlier u described I can use compression tester to change valve stem seals. There was mentioning of when I apply the 100 psi, so it seems there are two things going on and I mixed them up

1. If I want I want to do leak down for testing valve pressure I use the compression tester, that is very clear. If this way can be used to change seals please clarify.

2. My issue is broken valve stem seals , so I should use an air compressor with the Lisle valve holder and apply 100 psi to keep valve from falling and continue the process as mentioned in earlier post?


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DID some back yard garage stuff in my day. Old trick was to put a wad of cotton rope (thread it into spark plug hole- about a foot long) and hand crank engine by hand til it compressed the rope between valves and piston. This was done with rockers off. Rope pushed up on valves and springs/seals could be changed easily. Fixed many a broken valve spring at Sat nite dirt track races that way!!
 

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what david was saying is, the compressed air hose with spark plug threads can be used from a compression tester....
meaning ,
using that part of tester , connected to your air hose, along with a steady supply of air
while removing spring and keeper...the steady supply of air will maintain a constant pressure on valve, and keep valve from falling into cylinder....;)
 
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