Help fixing a leaky sleeve! Ideas!

[thetester]

I've got a little 25 hp chinesium tractor. So no real formal specs to toss around. I rebuild this thing new last summer. All new internals and seals.

The sleeves are wet press in with two 4mm thick orings as seals on the bottom of the sleeves. Seals off the coolant from the oil sump.

I Noticed the oil was overfill one morning and lucky I checked further. It had leaked coolant to the oil. I pressurized the radiator and found the sleeve in fact dripping coolant pretty quick.

Pulled the sleeves no rolled or cut orings. Turns out the block bore is likely just overbored (china quality) for the liners and orings. Enough just to barely screw up a good seal. I sized up to 5mm. Way to big and cut the orings right away. Went to 4.5mm same appear to want to fit but they get shaved on every attempt. Used soap then grease and oil. Still cutting the rings.

The only size the will push in without damage is the 4mm but they do so by hand. Not tight enough seal. Thought of freezing the sleeves first and warming the block to see if I coukd press the 4.5 orings. Not sure if I'd have any luck and orings are 5 bucks a pop. Already gone through 12.

Any ideas on getting a seal trustworthy with smaller orings? Any ideas of pressing the larger orings without cutting? I'm at a loss for new ideas short of cleaning it all with Acetone and using silicone around orings and the bore.

 

[thetester]

I've got a little 25 hp chinesium tractor. So no real formal specs to toss around. I rebuild this thing new last summer. All new internals and seals.

The sleeves are wet press in with two 4mm thick orings as seals on the bottom of the sleeves. Seals off the coolant from the oil sump.

I Noticed the oil was overfill one morning and lucky I checked further. It had leaked coolant to the oil. I pressurized the radiator and found the sleeve in fact dripping coolant pretty quick.

Pulled the sleeves no rolled or cut orings. Turns out the block bore is likely just overbored (china quality) for the liners and orings. Enough just to barely screw up a good seal. I sized up to 5mm. Way to big and cut the orings right away. Went to 4.5mm same appear to want to fit but they get shaved on every attempt. Used soap then grease and oil. Still cutting the rings.

The only size the will push in without damage is the 4mm but they do so by hand. Not tight enough seal. Thought of freezing the sleeves first and warming the block to see if I coukd press the 4.5 orings. Not sure if I'd have any luck and orings are 5 bucks a pop. Already gone through 12.

Any ideas on getting a seal trustworthy with smaller orings? Any ideas of pressing the larger orings without cutting? I'm at a loss for new ideas short of cleaning it all with Acetone and using silicone around orings and the bore.

Oh I do have a mill and lathe. I thought of widening the grooves of the sleeve. I'm thinking it's just not enough room for the rings to glatten out and squish. When pressed they are cutting ong the edges of the oring groove of the sleeve. Now that's just my observation guessing as you can't see what's actually happening only the result when they are pulled.

 

[mrmikey]

Thinking outside the box her so be gentle .
What about if you use the 4.5 or even 5mm orings, put a band/hose clamp around it while in place and tighten it up, maybe even a thick zip tie first and then a band clamp so you don't screw up the surface of the O ring with the serrations of the clamp. Then throw the whole setup, liner with clamped O ring in the freeze for a couple hours.
Is the edge of the block chamfered so it's a smooth entry into the machined surface.?

 

[thetester]

Thinking outside the box her so be gentle .
What about if you use the 4.5 or even 5mm orings, put a band/hose clamp around it while in place and tighten it up, maybe even a thick zip tie first and then a band clamp so you don't screw up the surface of the O ring with the serrations of the clamp. Then throw the whole setup, liner with clamped O ring in the freeze for a couple hours.
Is the edge of the block chamfered so it's a smooth entry into the machined surface.?

Great idea! I wonder if a cylinder ring compressor would work. Heck I have thin sheet stock to compress the rings.
Yes the block bore is chamfered and somewhat polished. Let's say it's very smooth for cast iron.

What's happening is the friction from pressing the sleeve is firstly pushing the orings up in the sleeve oring groove. While being compressed or squished, I don't think there is ample room in the grrove for the rings to squish out or flatten and overcome the friction at the sane time. They push up against that grooves edge and hence get cut.

If any of that makes good sense. I can take photos if anyone wants to give more help or direction.

 

[stuckmotor]

I've got a little 25 hp chinesium tractor. So no real formal specs to toss around. I rebuild this thing new last summer. All new internals and seals.

The sleeves are wet press in with two 4mm thick orings as seals on the bottom of the sleeves. Seals off the coolant from the oil sump.

I Noticed the oil was overfill one morning and lucky I checked further. It had leaked coolant to the oil. I pressurized the radiator and found the sleeve in fact dripping coolant pretty quick.

Pulled the sleeves no rolled or cut orings. Turns out the block bore is likely just overbored (china quality) for the liners and orings. Enough just to barely screw up a good seal. I sized up to 5mm. Way to big and cut the orings right away. Went to 4.5mm same appear to want to fit but they get shaved on every attempt. Used soap then grease and oil. Still cutting the rings.

The only size the will push in without damage is the 4mm but they do so by hand. Not tight enough seal. Thought of freezing the sleeves first and warming the block to see if I coukd press the 4.5 orings. Not sure if I'd have any luck and orings are 5 bucks a pop. Already gone through 12.

Any ideas on getting a seal trustworthy with smaller orings? Any ideas of pressing the larger orings without cutting? I'm at a loss for new ideas short of cleaning it all with Acetone and using silicone around orings and the bore.

I was about to suggest silicone before reading your last sentence.

 

[mrmikey]

Great idea! I wonder if a cylinder ring compressor would work

Thanks.
Probably work better than what I was suggesting, it being smooth inside and easy/fast to remove when you take it out of the freezer.