pug Posted March 3, 2010 Share Posted March 3, 2010 How hard is it to replace lifters and valve seals On a 1990 2.5 thanks Link to comment Share on other sites More sharing options...
jimoshel Posted March 3, 2010 Share Posted March 3, 2010 Define "Hard". Seals aren't to difficult, Just don't drop a valve into the cylinder.If you have a reasonably equipted shop the you know the air pressure trick. If you don't then use the rope trick. Remove the spark plug.locate the piston about half or 3/4 of the way up. Fill the cylinder with a length of rope. Rotate the crank until the the piston jams. Do the seal job. Back the piston off. Remove the rope. Lifters requires the removal of the head and for a 'V' engine the intake manifold. If your doing the lifters and seals at the same time, ignore the above info. Do the seals while the heads off. Link to comment Share on other sites More sharing options...
64 Cheyenne Posted March 3, 2010 Share Posted March 3, 2010 I'm kind of thinking the valve seals are bad on the 87. The engine runs and idles fine, if I rap it, it smokes, valve seals? Odometer says 140k. Link to comment Share on other sites More sharing options...
pug Posted March 3, 2010 Author Share Posted March 3, 2010 How hard is it to take of the cylinder head and while i have it of is there anything else i should replace. Link to comment Share on other sites More sharing options...
1986Comanche Posted March 3, 2010 Share Posted March 3, 2010 How hard is it to replace lifters and valve seals On a 1990 2.5 thanks My factory shop manual shows that the lifters can be removed on the 2.5L by pulling them up through the openings in the head where the push rods go down through. I hope this info helps. Link to comment Share on other sites More sharing options...
pug Posted March 3, 2010 Author Share Posted March 3, 2010 Sounds a lot easier. thanks Link to comment Share on other sites More sharing options...
jimoshel Posted March 3, 2010 Share Posted March 3, 2010 Quick smoke check. Go up a steep hill.Don't lug the motor but make it work. If it smokes your rings are worn. Turn around and go down the hill. Ride compression, No gas. If it smokes your seals are bad. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 3, 2010 Share Posted March 3, 2010 lifters can be done without removing the head on a 4 cylinder...but you will need some sort of grabber or the proper tool for pulling the lifters out, and putting the new ones in. seals, also not too bad. as stated, do the rope trick. make sure you use synthetic rope as it's less likely to fray and lose small pieces in the cylinder. the rope will have to be around 7/16 diameter to fit in. honestly, though, if I were doing the lifters and seals, I would be lapping the valves, too...that requires removing the head as well, which is easier with the intake/exhaust manifold off. obviously that requires a head gasket. Link to comment Share on other sites More sharing options...
pug Posted March 4, 2010 Author Share Posted March 4, 2010 Stupid question what is lapping the valves mean. Link to comment Share on other sites More sharing options...
dasbulliwagen Posted March 4, 2010 Share Posted March 4, 2010 Stupid question what is lapping the valves mean. Also know as grinding the valves, or renewing the mating surfaces between the valves and the valve seats... seats will also have to be ground. The "grind" is done at specific angles to allow proper seating and sealing... if youre doing this you should also have the head and block checked for warpage, and if any warpage exists, you will need to have either the head and or block surfaced or machined to remove the warpage and create a completely flat surface for the head and block to seal to each other with a new head gasket. Good Luck! Oh! Why do you beleive that you need new lifters? Are they ticking? Good luck! Link to comment Share on other sites More sharing options...
pug Posted March 4, 2010 Author Share Posted March 4, 2010 Yes the lifters are also valve seals are bad. It only has 65000 on reman engine. Runs strong just smokes alittle and ticks Link to comment Share on other sites More sharing options...
jpdocdave Posted March 4, 2010 Share Posted March 4, 2010 Stupid question what is lapping the valves mean. Also know as grinding the valves, or renewing the mating surfaces between the valves and the valve seats... seats will also have to be ground. The "grind" is done at specific angles to allow proper seating and sealing... if youre doing this you should also have the head and block checked for warpage, and if any warpage exists, you will need to have either the head and or block surfaced or machined to remove the warpage and create a completely flat surface for the head and block to seal to each other with a new head gasket. Good Luck! Oh! Why do you beleive that you need new lifters? Are they ticking? Good luck! just nit picking, but lapping is different than grinding. lapping is done by hand, and with a lapping compound. lapping will not seal a worn out valve or valve seat. grinding the valves and seat will be a new surface (valve job). lapping will renew slightly worn surfaces, and if you know how to interpret the results you will see what shape your valves and seats are in. Link to comment Share on other sites More sharing options...
1987Comanche Posted March 4, 2010 Share Posted March 4, 2010 I did the lifters and pushrods on my '87 2.5L in 1/2 a day. You need a lifter removal tool which is about $12 at Advance Auto. Lifters were $5/ea and pushrods were $2/ea. Also pick up a tube of slick assy lube. I thought it was fairly easy...required some patience but pretty straightforward. You can always go back and replace the valve stem seals later on. Just a general question: Why did AMC allow one to pull the lifters on the 2.5 without pulling the head but not the 4.0? Link to comment Share on other sites More sharing options...
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