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Thread: Any way to replace valve stem seal without taking off the head?

  1. #1

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    Any way to replace valve stem seal without taking off the head?

    Was trying to replace valve stem seals last summer because burning oil.... wasn't able to do so...succeeded in the front exhaust valve..I have two valve spring compressing tools,,they don't seem to work well on this engine....I am thinking of using zip tie...any experience on that?
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    Yes, you need to run compressed air into the cylinder by taking out a spark plug. The compressed air holds the valves sealed while your working. Or you could turn the pistons to TDC on each piston so the valves don't drop inside as you work on them. One other way is to put a rubber band around the stem so they don't drop in also.

  3. #3

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    Quote Originally Posted by BradMph View Post
    Yes, you need to run compressed air into the cylinder by taking out a spark plug. The compressed air holds the valves sealed while your working. Or you could turn the pistons to TDC on each piston so the valves don't drop inside as you work on them. One other way is to put a rubber band around the stem so they don't drop in also.
    thanks for your advice. My question really is how to compress the valve spring... It does not seem very easy to do.... any tools that have been proven to work?

  4. #4

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    A zip tie isn't gonna work. I used a valve spring tool on mine with no problems. Post a picture of the tools your trying to use.

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    Ya there is a tool, cost about 13 bucks I think. Throw away after, if it's done. I saved mine, but they do get worked a little after doing 4 heads. I had one incident when the spring on my truck shot out of it and hit the garage wall almost sticking in. Just be careful and you will do just fine. Be sure to fill those new seals with pre-run grease also. Hate to scar them up in your initial startup.

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  6. #6

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    Quote Originally Posted by BradMph View Post
    Ya there is a tool, cost about 13 bucks I think. Throw away after, if it's done. I saved mine, but they do get worked a little after doing 4 heads. I had one incident when the spring on my truck shot out of it and hit the garage wall almost sticking in. Just be careful and you will do just fine. Be sure to fill those new seals with pre-run grease also. Hate to scar them up in your initial startup.

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    I have a similar style valve spring compressing tool, but not identical.... I think I got it from Harbor freight.... The problem I had was the pawl not able to grab the last few coils of the spring..... Maybe I should try another one with longer stroke and smaller pawl?

  7. #7

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    Quote Originally Posted by BradMph View Post
    Ya there is a tool, cost about 13 bucks I think. Throw away after, if it's done. I saved mine, but they do get worked a little after doing 4 heads. I had one incident when the spring on my truck shot out of it and hit the garage wall almost sticking in. Just be careful and you will do just fine. Be sure to fill those new seals with pre-run grease also. Hate to scar them up in your initial startup.

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    Hello Bradmph,

    Uploaded is the pic of the tools that I used....They don't seem to have enough grab....I am thinking of getting another tool or modify the pawls .. What do you think?
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    Modify the paws, they have enough to squeeze springs. The one I showed was decent enough to squash heavy duty Schneider after market springs I installed when I had my cam grinded.

    Your spring crushers looks better then what I had, the one I posted is a little different by the jaws. Mine was a single jaw where the image there looks like 2 jaws. The tools rivets were the thing that took the punishment and I just laid a hammer on them and flatten them out a bit to stable up the tool.
    I even did a set of 302 V8 heads with mine by removing all the springs and re-installing double springs with a lot more pressure then the Mitsubishi engine springs.

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  9. #9

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    Old aircraft mechanic trick. Take all the plugs out. Get piston to TDC for the cylinder then back it up until piston is at bottom.
    Now feed fresh rope through spark plug hole and leave some hanging out. Rotate engine toward TDC pushing the rope against the valves.
    Do your valve seal work then rotate engine backwards enough to be able to pull the rope out.

  10. #10

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    i know that the thread is old but i would like to give some advice for anyone who is doing this. i changed my valve stems without air or string and it was really simple.

    what i did was head over to autozone and rented there valve spring compressor tool (its the oneBradMPH has pictured) and also got there fel pro valve stem seals. they should come with a sleeve to slip over the valve stem so as not to damage the seal during installation. also i got an oil change and seafoam for after the job was done. also got a new valve cover gasket set.

    alright so i removed everything up top along with the cam. the next thing i did was set the number one cylinder to top dead center. one of the issues i had was getting the keepers loose, how you can do this is take a deep socket 12mm with a 2inch extension and put it over the valve stem were the keepers are and give it a good 3-4 taps with a hammer enough to move the spring up and down 1/16''. this will loosen the keepers. for me this was a MUST because i did not use air to keep the valves in place so that i could just push the spring down after the were compressed to remove the keepers. next i got my compression tool griped on the second coil up from the bottom on the valve spring. i used a screw driver to lift it a little so i could get the tools paws in there but be careful and dont damage the valve stems. next i compressed the spring, the keepers should come loose and at this point i took one of those magnet pen things to grab the keepers. on mine the valve would drop down so using a small scratch all to keep the valve up and the magnet to remove the keepers worked great for me. (use the scratch all to hold the valve up at the keeper grooves). i then removed the valve spring, lower shim and then removed the seal with a seal remover tool. i cant find the one i used online because its quit old and i got it from my dad who worked for Chrysler back in the 1980s. anyway at this point i oiled up the seals with some synthetic motor oil, placed the sleeve over the stem that came with the seals and them pushed the seals on by hand(Important!!, they should go on by hand, just give them a good press down). now the valve was resting on top of the piston just right during this process so i simply did not need the air. i did try using air at first to keep the valve up with the cylinder at 90 psi but the valve did not stay up well enough so the TDC trick with the scratch all and 12mm socket worked great for me. did the same for the rest of the valves working towards the front to the back placing the piston corresponding with the valve i was working on at TDC (Top Dead Center) until they were all done. also it might help to have someone with you when you do it this way.

    before doing this i would go threw a qt of oil every 900 miles and it would puff out a small cloud of smoke at cold start. now it has not eaten a amount of oil sense i have done this 250 miles ago and does not smoke at start up.

    hope this helps anyone

  11. #11

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    cant edit my previous post to add this but its been 3000 miles and the truck uses a little less than 3/4 quarters of a qt. with the oil between min and max on the stick. if it stays like this than i will be happy. these motors tend to burn more oil because of the longer stroke and overall design so im cool with this much being consumed so long as it does not increase.

  12. #12

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    Quote Originally Posted by elsupremo View Post
    Old aircraft mechanic trick. Take all the plugs out. Get piston to TDC for the cylinder then back it up until piston is at bottom.
    Now feed fresh rope through spark plug hole and leave some hanging out. Rotate engine toward TDC pushing the rope against the valves.
    Do your valve seal work then rotate engine backwards enough to be able to pull the rope out.
    This is how you do it!

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