Valve Stem Seal - New Genuis Idea?

[barnesen]

Balloons. I've seen the rope trick, I've seen the compressed air trick. Has anyone tried balloons?

1. Lower Balloon into cylinder
2. Inflate balloon until it fills cavity.
3. Tie off balloon - this is important. :-)
4. Replace valve stem seals.
5. Hold balloon stem, deflate/pop balloon and remove.

Has anyone seen this done? Does it conceptually work? What am I missing?

Genius or madness?

[richhead]

barnesen said:

Balloons. I've seen the rope trick, I've seen the compressed air trick. Has anyone tried balloons?

1. Lower Balloon into cylinder
2. Inflate balloon until it fills cavity.
3. Tie off balloon - this is important. :-)
4. Replace valve stem seals.
5. Hold balloon stem, deflate/pop balloon and remove.

Has anyone seen this done? Does it conceptually work? What am I missing?

Genius or madness?

it would have to be a very strong balloon, but in theory it should work, not sure why you would tho, plenty of other ways to do it.

[barnesen]

You might be right about the strentgh of the balloon. Might make it impossible
Thanks for the response!

[Sardonicus]

You would need the balloon strength of a WW1 period condom to resist them valves pushing down into the chamber especially breaking the valve collet/keeper hold in the spring caps for starters

[rev-erend]

Too many sharp edges

[liner33]

Piston would need to be at the top of the stroke , you'd never get a balloon in there

[barnesen]

Good points. i'm now thinking a bladder instead of a balloon, like a air surge bladder, or like the air shim like the AirShim Inflatable Pry Bar and Leveling Tool that Holds Up To 300 lbs. Rope or air is looking better...

[liner33]

Air works fine , I use my leakdown tester* , no need to reinvent the wheel

• not that I have done it for some years

[Mercdriver]

I once did this use strong twine like thick sisal, remove plug, pushed string into cylinder brought piston up to compress it and locked crankshaft off. Changed seals

This was done on an old car with a lot lower compression ratio many years ago, not sure if it would work on modern cars with higher compression, if OHC would not be worth dismantling only the shaft(s) may as well take the head off if you have got that far

Worth a try though at the end of the day you will still have to take the head off to replace the seals. If the car has done so many miles the seals are leaking would you not want to strip the head and lap in the valves anyway?

[GreenV8S]

The rope trick is low tech but pretty foolproof.

[shakindog]

Once used my boot laces instead of string to change valve spring on a Mini Cooper s.
Gotta use what you got to hand
It’s not stupid if it works
Took longer to find the collet that I dropped in the grass

[Sardonicus]

GreenV8S said:

The rope trick is low tech but pretty foolproof.

Agreed and liner33 I would presume you would run the piston down the bore a bit before inserting the balloon then bringing back to TDC before inflation ....it dont matter anyway the whole idea seems daft to me