Valve seal replacement
#1
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Year: 94
Model: Cherokee
Engine: 4.0
Valve seal replacement
Is it easier to take the head off to replace valve seals or leave it on? If I take it off should I take the head and have it checked for flatness and cracks since there is nothing wrong with the head gasket? Any special tools needed to take the springs off?
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Year: 1993
Model: Cherokee
Engine: 4.0
If you have a air compressor you can hollow out a spark plug and clamp a hose from it to the hollow spark plug. Then just do one cylinder at a time by putting your jig in place of the good spark plug fill with air back clamp your air hose to keep the air in the cylinder and use a special style valve spring compressor which i believe you can "rent" from your favorite parts store.
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Year: 1993
Model: Grand Cherokee
Engine: 4.0L Laredo
If you're replacing the valve guides, I'd just pull off the head and have a machine shop make it like new. Got mine done for about $75 + new head gasket etc. If I recall correctly, the valves are ground with the new guides installed so they seat properly.
#4
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Year: 1990
Model: Cherokee (XJ)
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I've done them in the Jeep before. Pretty easy. No more oil burning either.
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Besides compressed air;
You can feed a length of small braided nylon cord into the spark plug hole then CAREFULLY BY HAND, turn the engine via the crank pulley bolt to bring a piston there up on compression to hold the valves up while you change the seals.
Assuming you left the end of the cord out, you then just remove it and go to the next, (in the firing order).
I wouldn't want to twist the braided nylon, or use something that might tangle up in there. (feed it straight in).
Just thought you guys might like that one, I haven't tried it myself. (I did learn that a 72 cu/ft SCUBA tank only holds enough air to do two).
You can feed a length of small braided nylon cord into the spark plug hole then CAREFULLY BY HAND, turn the engine via the crank pulley bolt to bring a piston there up on compression to hold the valves up while you change the seals.
Assuming you left the end of the cord out, you then just remove it and go to the next, (in the firing order).
I wouldn't want to twist the braided nylon, or use something that might tangle up in there. (feed it straight in).
Just thought you guys might like that one, I haven't tried it myself. (I did learn that a 72 cu/ft SCUBA tank only holds enough air to do two).
#6
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Year: 1990
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[QUOTE=DFlintstone;1634105]Besides compressed air;
You can feed a length of small braided nylon cord into the spark plug hole then CAREFULLY BY HAND, turn the engine via the crank pulley bolt to bring a piston there up on compression to hold the valves up while you change the seals.
Assuming you left the end of the cord out, you then just remove it and go to the next, (in the firing order).
I wouldn't want to twist the braided nylon, or use something that might tangle up in there. (feed it straight in).
Just thought you guys might like that one, I haven't tried it myself. (I did learn that a 72 cu/ft SCUBA tank only holds enough air to do two).
I've done the rope trick. Works well. Rent/borrow/buy one of those spring compressors that collapse the valve springs without removing the head and you're in business.
You can feed a length of small braided nylon cord into the spark plug hole then CAREFULLY BY HAND, turn the engine via the crank pulley bolt to bring a piston there up on compression to hold the valves up while you change the seals.
Assuming you left the end of the cord out, you then just remove it and go to the next, (in the firing order).
I wouldn't want to twist the braided nylon, or use something that might tangle up in there. (feed it straight in).
Just thought you guys might like that one, I haven't tried it myself. (I did learn that a 72 cu/ft SCUBA tank only holds enough air to do two).
I've done the rope trick. Works well. Rent/borrow/buy one of those spring compressors that collapse the valve springs without removing the head and you're in business.
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