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-   -   Changing valve seals (http://www.jeepgarage.org/f196/changing-valve-seals-31248.html)

Frango100 11-17-2011 07:32 PM

Changing valve seals
 
My 4.7 is burning oil for some time and its getting worse. Just ordered a new set of valve seals (which i hope are the trouble makers), but would like to know how difficult it is to change them. I heard about the rope trick, where you put an end of rope inside the cylinder through the ignitor hole (with still a part sticking out:D) and then bring the piston up, so that the valves will not fall down when removing the lock halfs. Does this really work well? Do i need to buy a special tool to compress the valve springs, or is there also some "trick" to get it done?

01grand 11-17-2011 10:12 PM

Re: Changing valve seals
 
I have no idea but good luck with the work!

Me Fix 11-18-2011 04:00 PM

Re: Changing valve seals
 
I did this job once, but it was on an old 68 Ford 428 engine. I took a spark plug and broke out the center and welded in a air chuck fitting. I could then screw the plug into a spark plug hole, one at a time, and attach an air line to the fitting. The air pressure held the valves in that cylinder closed while I replaced the seals around the valve stem. As far as a special valve spring compressor, I don't know with the newer engines. I do remember someone told me that after I got the new seals installed and the keepers back in place, I was to tap the top of each valve stem with a hammer to make sure the keepers were seated. Each valve had two pieces that made up the keepers and you didn't want them to be out of place when you fired up the engine!

2005JGC 11-19-2011 02:41 AM

Re: Changing valve seals
 
I havent done valve stem seals without the head being off and torn down on my bench for something like a head gasket repair, IIRC you can work the rockers out from under the cam in which case you need a simple spring compressor tool like similar:

http://espimages.biz/2386/I/864/7/VS168.jpg

the hooks grab the camshaft and then the arms go down on the retainer, use a magnet to grab the keepers, tapping the valve with a hammer as mentioned prior to this action can halp in removal of stubborn keepers.

You will be fine running nylon rope down in the cylinder, I personally use the air method mentioned above with my cylinder leakage tester, the nice thing is with the rockers out you dont need to worry about being TDC compression for the valves to seal ;)

Again I say all this not actually having done it, in theory this is how it should work, I generally use a large clamp style on a bench if I am doing it.

Frango100 11-19-2011 06:18 AM

Re: Changing valve seals
 
Ok, thanks for the replies guys. Not sure yet if i'm going to tackle this in my own garage (where i have no shopair) or have to look for a place where i could use shopair to keep the valves in place. Maybe i will try the rope trick, does anyone have an idea how much of rope should be used?

Me Fix 11-19-2011 12:17 PM

Re: Changing valve seals
 
Enough rope will do! all kidding aside, it sounds risky at best. If the rope piles up on one side, it may not hold the valves in position. Should they drop even a little, it could be very hard putting the keepers back on after you get the seals in place. The spring might keep you from doing anything to help keep the valve all the way up. I think I would buy the "leakage tester" plug and then find a friend who might have a neumatic nailer that uses a compressor. They might let you borrow the compressor and then you will be doing this the best way. It really doesn't take much air unless you are leaking alot.

2005JGC 11-19-2011 01:40 PM

Re: Changing valve seals
 
never mind, just learning how to read for the first time here, nothing to see folks, move along.

hoffmanestates 11-20-2011 10:28 AM

Re: Changing valve seals
 
i tore my motor apart just last night both heads off. and i went to JEEP and they printed me info/pics from their online service manual... there is a special"" tool they use to compress the rocker so u can get the lock and seal visable. but of course my jeep doesnt borrow tools anymore due to tards breaking them or never giving back.... but yes u need to push air into the cyl. to keep the valves up.....if u drop one u will be tearing that side of in a jiffy. and they make special tools for thta also.. its a wedge and other dew hickeys MATCO/snapon sell them... that keeps your other head in time and u disasemble the other..... i can take pics if u want of the heads at different angles before i give them to the machine shop

Frango100 11-20-2011 04:20 PM

Re: Changing valve seals
 
Ok, thanks again for the responses. I will have to see which type of tools we have available overhere and which will work on this engine.

hoffmanestates 11-20-2011 04:24 PM

Re: Changing valve seals
 
lol..... yeah out here by me even the chrysler the guys dont wanna look at it.......

2005JGC 11-20-2011 05:26 PM

Quote:

Originally Posted by hoffmanestates (Post 518597)
i tore my motor apart just last night both heads off. and i went to JEEP and they printed me info/pics from their online service manual... there is a special"" tool they use to compress the rocker so u can get the lock and seal visable. but of course my jeep doesnt borrow tools anymore due to tards breaking them or never giving back.... but yes u need to push air into the cyl. to keep the valves up.....if u drop one u will be tearing that side of in a jiffy. and they make special tools for thta also.. its a wedge and other dew hickeys MATCO/snapon sell them... that keeps your other head in time and u disasemble the other..... i can take pics if u want of the heads at different angles before i give them to the machine shop

Other than a tool to compress the valve spring, you dont need to remove the cams that said you dont need the wedge tool.

Sent from my SCH-I500 using Tapatalk

Frango100 12-03-2011 09:55 PM

Re: Changing valve seals
 
So the valve seals came in yesterday, a compressor and sparkplug adapter where available and a friend lend me some valve spring compressors..........................
After removing the head cover, a nice and clean engine internal came in view. No sludge or buildup.
Then the hard part came, the valve spring compressors didnīt work on this engine, there is not enough space. I improvised a tool and took the keepers of. Then an other battle to get the seal of its place. It finally went by using a screwdriver, but i saw on internet that there are special tools available to pull the seal.
To make a long story short, i only changed one valve seal today. Maybe have to make that tools which 2005JGC was showing and get some special tool to pull the seals. Just wondering how changing those seals will go at cilinders 6 and 8.................:( Anybody overhere who did this with the engine in place?


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