valve stem seal replacement only with compressed air threads? (2 Viewers)

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landcruiser3DP

landcruiser3DP

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has anyone done a good documentation of doing valve stem replacement with compressed air?
anyone got links please?
also is there consensus on if this is worthwhile?
it now has 250K.
an oil sample report from blackstone came back good after i bought it.
i had an old time toyota tech do a borescope recently when i did plugs etc and they said the cylinder walls still had cross hatching and things looked good. they also did a compression check which came back good (i could find it and post results).
anyway i think it's time to do seals.
would i need to pull the engine if i don't do just seals? what other work would/should i add to this job (like can someone just give me a thumbnail rundown again of what i am in for so i can get my head around it)?
THANKS
 
Is it burning oil?

If it's not burning huge amounts of oil, may not need to rush to it.

If you do do it, change all hoses, rubber seals, gaskets etc that you disturb.

To change valve seals you're a fair way into pulling the head off
 
It's possible to do without pulling the engine or the head. Tricky, but possible.

If the HG is in good shape, i'd try to do it this way to avoid changing the HG. Not because changing HG is particularly difficult, but because doing it can open a whole new can of worms that you really want to avoid.
 
mudgudgeon said:
Is it burning oil?

If it's not burning huge amounts of oil, may not need to rush to it.

If you do do it, change all hoses, rubber seals, gaskets etc that you disturb.

To change valve seals you're a fair way into pulling the head off
Click to expand...
thanks man.
i keep trying to find time to write up a list of parts for a full job - i also have two write down what the full job is in thumbnail form at some point just so i know i have a strategy.
but it sounds like it is kind of worthwhile doing this method for valve seals?
also i can never figure out if engine comes out if i do the full job. hood comes off i guess and i get a lift to pull it out with someone? i mean to properly do it and give it some elbow grease in cleaning it up?
 
TurboDennis said:
It's possible to do without pulling the engine or the head. Tricky, but possible.

If the HG is in good shape, i'd try to do it this way to avoid changing the HG. Not because changing HG is particularly difficult, but because doing it can open a whole new can of worms that you really want to avoid.
Click to expand...
thanks. i was talking to a guy and he got me started again in this.
is there somewhere i can go to get started in a plan?
he seemed to say he had someone fab up a spark plug or something so he could continuously blow air into the engine after taking the valve cover off? and i have a big construction site makita compressor that rusts sound waiting to earn its keep.
but I'm much better with step by step layouts with images.
anyway i will start researching if there are any videos on this and post them here in the meantime.
 
I would suggest watch Otramm's video on head replacement.
Its a great resource, and the process will be more or less the same, until you have cams, and valve shims and buckets removed.
Then you would deviate to just charge seals rather than removing head bolts, head etc

If you want to do seals without taking the head off, this is kind of a corner & cost cutting excercise. It would not make sense to remove the entire engine to replace seals without removing the head.

If you were to go to the trouble of removing the engine, remove the head, have it inspected, and refreshed.
 
A couple of hints from working on a 2F in a '75 FJ40. Turn the crank so that the cylinder being worked on has a piston at tdc. This way, if a valve drops, due to lost air pressure, or accidentally pushing down on the valve without the spring holding it up, it won't fall all the way into the cylinder. Also, stuff rags in the pushrod roles, to prevent any fugitive spring-keepers from falling thru the head, and use a magnet to pick up the keepers.

I made a lever-type spring compressor with angle iron that had holes drilled in it, and bolted a piece of steel on the side of the head to use as a fulcrum.
 
mudgudgeon said:
I would suggest watch Otramm's video on head replacement.
Its a great resource, and the process will be more or less the same, until you have cams, and valve shims and buckets removed.
Then you would deviate to just charge seals rather than removing head bolts, head etc

If you want to do seals without taking the head off, this is kind of a corner & cost cutting excercise. It would not make sense to remove the entire engine to replace seals without removing the head.

If you were to go to the trouble of removing the engine, remove the head, have it inspected, and refreshed.
Click to expand...
hey. thanks for all your help as always.
i think what i was trying to drive at is i could do this valve stem seal job snd hit tank the baffle in the valve cover as a kind of first mechanical with the engine in the truck.
then if/when the time comes to do the whole job i could take off the hood and remove the engine and do the engine outside the truck?
just curious but is it a viable option i guess to buy an engine and refurb it on a stand slowly?(!)
 
Grayscale said:
A couple of hints from working on a 2F in a '75 FJ40. Turn the crank so that the cylinder being worked on has a piston at tdc. This way, if a valve drops, due to lost air pressure, or accidentally pushing down on the valve without the spring holding it up, it won't fall all the way into the cylinder. Also, stuff rags in the pushrod roles, to prevent any fugitive spring-keepers from falling thru the head, and use a magnet to pick up the keepers.

I made a lever-type spring compressor with angle iron that had holes drilled in it, and bolted a piece of steel on the side of the head to use as a fulcrum.
Click to expand...
i need to study up on this.
i would probably go to ace hardware and home depot etcetera and gather up some plugs.
i'm not totally sure if the guy that got me back in to this wasn't talking about an FJ40 actually.
but anyway - a sort of worst case scenario with this job is to drop something into a - well would it go into one of the holes? how does anything get down thru the cylinder bore if the cylinder is in it?
also what is meant by a valve dropping? is 't there a seat in the engine block between the keepers and the springs?
sorry i am just studying up here so apologies if i am slowly working up to it here.
 
When a piston is at the top position, it is close to the valve face itself, and when the piston is at the bottom of the stroke, the valve can drop thru the valve guide. When the cylinder is pressurized with compressed air, the air pressure holds the valve closed against the head. If you accidentally push on the valve stem while the air compressor is pressurizing the cylinder thru the spark plug hole, air will escape thru the respective intake or exhaust port, and if the keepers and valve springs are not installed, there is nothing to keep the valve up.

I lost a keeper in the pushrod (2F) hole. I had to fish it out with a magnet on the end of a carbide scribe. But, I lost the scribe in the hole as well. It was a mess that I could have avoided by closing the hole with a rag.

As far as I can tell, the overhead cam wouldn't use the same homemade spring compressor as the 2F. Aside from a different spring compressor, and different style of valve stem seals, it seems to be similar as far as equipment and repair procedure?
 
Grayscale said:
When a piston is at the top position, it is close to the valve face itself, and when the piston is at the bottom of the stroke, the valve can drop thru the valve guide. When the cylinder is pressurized with compressed air, the air pressure holds the valve closed against the head. If you accidentally push on the valve stem while the air compressor is pressurizing the cylinder thru the spark plug hole, air will escape thru the respective intake or exhaust port, and if the keepers and valve springs are not installed, there is nothing to keep the valve up.

I lost a keeper in the pushrod (2F) hole. I had to fish it out with a magnet on the end of a carbide scribe. But, I lost the scribe in the hole as well. It was a mess that I could have avoided by closing the hole with a rag.

As far as I can tell, the overhead cam wouldn't use the same homemade spring compressor as the 2F. Aside from a different spring compressor, and different style of valve stem seals, it seems to be similar as far as equipment and repair procedure?
Click to expand...
hey man. appreciate all this.
so if i am tracking i need some kind of valve spring compressor? and this is to compress the spring to remove the keeper so the valve is free in some way? anyway i guess i need to review the manual on this.
then i need some kind of compressor attachment welded to a spark plug with the cor knocked out or something so i can pressurize the engine?
at that point i am kind of pulling out an old seal and putting in an dee seal? and then putting the keepers back on or something?
also maybe a dumb question but how many TDC's are in a 6 cylinder engine? and also how do i register the engine at TDC for each cylinder? i'm lining up some marks on the flywheel? where do i find them please?
THANKS
 
landcruiser3DP said:
hey man. appreciate all this.
so if i am tracking i need some kind of valve spring compressor? and this is to compress the spring to remove the keeper so the valve is free in some way? anyway i guess i need to review the manual on this.
then i need some kind of compressor attachment welded to a spark plug with the cor knocked out or something so i can pressurize the engine?
at that point i am kind of pulling out an old seal and putting in an dee seal? and then putting the keepers back on or something?
also maybe a dumb question but how many TDC's are in a 6 cylinder engine? and also how do i register the engine at TDC for each cylinder? i'm lining up some marks on the flywheel? where do i find them please?
THANKS
Click to expand...
compression values last summer in PSI were:
1. 185
1. 185
3. 170
4. 175
5. 185
6. 175
he said he cleaned the throttle body. cranked it 4-6 times doe 10-15 seconds. had the throttle plate wide open and took the highest value.

on borescope he could still see cross hatching. some vertical scoring but nothing significant.

spark plug tubes were clear of oil.
 
My compression readings are similar to yours: four @180 psi, two @176. I am not burning any significant oil and after 20,000 miles, these are the plugs. Unless you have something very different going on I would leave the seals alone for now.
IMG_2201.jpeg
 
BTLSHP said:
My compression readings are similar to yours: four @180 psi, two @176. I am not burning any significant oil and after 20,000 miles, these are the plugs. Unless you have something very different going on I would leave the seals alone for now.View attachment 3783354
Click to expand...
i'm burning oil. went through all the usual suspects and the only thing left seems to be seals or possibly a clogged valve cover baffle which i think i can take care of by "hot tanking" it at the same time while its off?
i still have a bit of a hard time knowing what is where but i figure if i do this job it would be a decent run though for doing a full refresh?
i did a BG oil treatment which seemed to be recommended on here awhile back but it only made it worse.
 
IF you go ahead with this adventure, forget using compressed air. A much simpler approach with much less chance of screw ups while you are at it, is to feed a length of small diameter rope in through the sparkplug hole and then bring the piston up toward the top of the stroke until the rope will not let it come up any more. This will solidly and definitely keep the valve in place. Compressed air is not as assured to do so. And there will be no leakage of rope... and the rope will not be trying to push the piston down.

Freeing the valves from the keepers and retainers is a lot tougher on the 1fz than the old F series engines, old chevy small blocks and the like.

While it might sound like a cool idea, I just about guarantee that you will not be able to dislodge the keepers with only compressed air holding the valve in place.

I'd not recommend it as an undertaking for a low experience low knowledge beginner's project.

"i did a BG oil treatment which seemed to be recommended on here awhile back but it only made it worse." There is no truth to any claims of "miracles in a can" to solve any actual mechanical problem.


Mark...
 
here is @Doso explanation:

1- The battery was disconnected
2- I took out the air box
3- I removed the throttle body and heater valve
4- Removed the plug wires and the valve cover
5- removed the cam shafts and the valve shims

DO NOT TAKE OUT THE HEAD BOLTS

6- Use a compression tester as shown in the video to hold the valve in place.

a- Screw the tester instead of the spark plug
b- Use about 40 psi
c- Then and only then take out the valve keepers.

7- Replace the valve seals
8- Reinstall all components in the reverse order
 
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