Replacing Valve Seals

[bdazzgt]

I need to replace my valve seals in my car, the machine shop used some POS seals, and they need replaced after 35xxx miles. How is this done exactly? The car smokes on start up, and if it idles for and extended period of time. It burns a little bit of oil also. What kind of seals do i need? Are there better quality ones? I need to leave the heads on the motor because i dont have the $$ to replace gaskets bolts ect. What tools do i need and how do i do this? I need all of the help i can get. Thanks guys-James

 

[jtfairlane]

It is much more difficult and time consuming to replace valve stem seals with the heads on the motor instead of off...

With that said, in order to replace the valve stem seals with the heads still on the block, you will need to do the following:

You will to remove all of your sparkplugs. You are doing this because you will need to use compressed air with a hose/adapter to thread into the spark plug holes.

You will need to remove you upper intake manifold so that way you can have access to remove your valve covers.

With the valve covers off, and the spark plugs out, now you can start working on getting access to the valve stem seals.

If you don't already have one, you will need a valve spring compressor. You can rent one from a local parts store.

You will need to remove all the rocker arms, to release tension on the valves/valve springs. Now, with the rocker arms out of the way, start pulling valve springs one at a time to replace all the valve stem seals. FOR EVERY VALVE YOU ARE WORKING ON, MAKE SURE THAT YOU HAVE FILLED THAT CYLINDER WITH COMPRESSED AIR THROUGH THE SPARK PLUG HOLE OR YOU WILL DROP A VALVE IN THE CYLINDER!

You will use the valve spring compressor to compress each valve spring, remove the two keepers (locks), the retainer, and then decompress the spring so you can remove it from the head. With the valve spring off, you can slide the valve stem seal off the valve stem, and replace it with a new one.

Reassembling the valve spring package is a reversal of the removal process.

Go 1 by 1 until you are all done, making sure not to forget to keep using compressed air in each cylinder to keep the valve seated while the springs are removed.

 

[TC93]

If you don't have the fitting to use the air , you can do it the back yard mechanic way. Use some 1/8 vacum line or rope in the clyinder. Make sure the piston is down some on the cylinder you are working on, feed the line into the clyinder(spark plug opening), be sure to leave enough out so it can be unistalled. I used about 3 feet of line and filled the clyinder with as much as I could. Once filled,, rotated motor over( slowly & by hand) until piston moves up and holds valves in place, then you can remove the spring and replace seal. Once that cylinder is done,, rotate engine back some to remove the line from cylinder.


And once you put the locks back in the valve retainers, be sure to seat them, by hitting the top of the valve with a rubber mallet a few times. No need to kill it, just couple good blows. Then remove the lince or release air pressure in cylinder..

 

[Foxslider]

So i have to do my valve seals now. It's just burning too much oil and causing me power loss at at this point. Assuming its only the valve seals for now...

While im at it, Im going to take my heads off and have them milled .030. . zero three zero. Off topic: B/c after reading threads elsewhere i see people don't understand the difference between .3 and .030. That irritates the hell out of me. Kind of like car micheal (i think is his username) with the spelling. lol. Anyway, carrying on...

I'm also going to DIY port the E7's and do the trickflow spring kit since i'm low on funds (somebody got fired) and need to do these valve seals now.

#1 My dumb question is, how do i get the valves back in with the spring compressor tool... Ok i went and looked at the tool, looks like it tightens down and will stay by itself. So i can then just slide the valve in with one hand and put the lock back on with the other. Correct?

#2 Checking spring height, What kind of tolerance do i have there. .020? In the description it says 1.800. I assume, shoot for 1.800? I was gonna let the shop reassemble them, but it think it will be cooler and cheaper to do it myself.

#3 Would i need different pushrods by milling the heads .020 or .030?

Any thoughts, feedback appreciated on the whole top end tear down and rebuild in general or anything. Like new thermostat, PCV, headbolts, good head gasket etc...

 

[Mustang5L5]

#1 My dumb question is, how do i get the valves back in with the spring compressor tool... Ok i went and looked at the tool, looks like it tightens down and will stay by itself. So i can then just slide the valve in with one hand and put the lock back on with the other. Correct?

#2 Checking spring height, What kind of tolerance do i have there. .020? In the description it says 1.800. I assume, shoot for 1.800? I was gonna let the shop reassemble them, but it think it will be cooler and cheaper to do it myself.

#3 Would i need different pushrods by milling the heads .020 or .030?

Any thoughts, feedback appreciated on the whole top end tear down and rebuild in general or anything. Like new thermostat, PCV, headbolts, good head gasket etc...

#1. Depends on which compressor you are using. If you are changing the valve seals, then you need to remove the compressor and spring anyway. Depending on your springs, those cheapo $10 ones may not have the mustard.

#2. Shoot for exactly 1.800" with a tolerance of 0.020" and limit variation between all 16 to no more than 0.005"

#3. yes, you should measure for new pushrods and check PTV clearance which will change depending on cam and other parts selected