Piston sleeve removal
- Thread starter Chris Mme P
- Start date
I used to take them out with a large block of wood and sledgehammer. Nowadays I'd get an engineer to press them out.
Attachments
The liners can crack if hit directly with a metal hammer.
- Joined
- Aug 2, 2000
- Messages
- 11,457
WILL crack. I remember tapping the top of 404 liners to help them to seat. Ended up with dents but over time they returned to being smooth again. PeterT said similar thing about distorted Mi16 liners returning to normal after being put on the shelf for a while.
I'm guessing you've got the same bits of flat plate at the bottom as well?
Once the plates start to bend like that it's never going to move.
As others have said you need more rigid plates.
Even the ones you have, if you straighten them out and weld them together on the sides, they will be much stronger, they are working like a leaf spring the way they are. I'd probably weld 3 or 4 together though as it only looks like 6mm plate?.
That bolt through the middle doesn't look very big either, so once you get the plate rigidity sorted you may find that the bolt will shear off before anything moves.
I'd use a 3/4" HT bolt as a minimum or alternatively use two smaller bolts closer to the edges of the cylinder. The plates will be less likely to deform with two bolts spread apart like that, however you will have to be diligent at keeping the tension equal on both bolts.
Once the plates start to bend like that it's never going to move.
As others have said you need more rigid plates.
Even the ones you have, if you straighten them out and weld them together on the sides, they will be much stronger, they are working like a leaf spring the way they are. I'd probably weld 3 or 4 together though as it only looks like 6mm plate?.
That bolt through the middle doesn't look very big either, so once you get the plate rigidity sorted you may find that the bolt will shear off before anything moves.
I'd use a 3/4" HT bolt as a minimum or alternatively use two smaller bolts closer to the edges of the cylinder. The plates will be less likely to deform with two bolts spread apart like that, however you will have to be diligent at keeping the tension equal on both bolts.
Thanks for the replies. Yes same flats at the bottom. I was expecting with that tension a few hits with the hammer would crack them though knowing they are cast iron I didn’t want to crack the lip off so wasn’t laying into them with the hammer. I hadn’t thought of using 2 bolts, though I think I need to make up something a lot more robust.
I've removed a few very stuck liners from an engine (not Pug) with a DIY puller. A block of hardwood drilled to sit on top of the protruding and quite long head studs (not present in your picture, but easily added), a length of threaded rod (>1/2"), long 'coupler' nut (see below per Bunnings), suitable washers etc. and an 1/4"+ aluminium plate (< liner OD) under the bottom of the liner. No damage and it just pulled the liners out with little effort
You were probably lucky that the liners weren't really stuck. I managed to destroy properly stuck liners with improvised pullers after I had bent steel plate that thick (it became a cone and pulled inside). No loss, I just wanted the block. These days I would turn a steel disc say about 1cm thick and use a machinist clamp to pull from the top if I wanted to save the liners.
In a pinch, I would use a few washers of increasingly larger diameters (hopefully to almost the same diameter as the disc) under the nut at the bottom to reinforce a thin disc of steel against bending.
In a pinch, I would use a few washers of increasingly larger diameters (hopefully to almost the same diameter as the disc) under the nut at the bottom to reinforce a thin disc of steel against bending.
Having an open deck as in something like a PRV or ID/DS engine would make life easier too since you only have the lower part holding it in. It's probably smart not to make your tool too robust as the tool failing would be the cue to see a pro and not do DIY damage. Yes, some large washers to spread the load would help.
I can give a definitive answer to how to get them out EVERY time.
The problem is not a lack of outward force made by some extraction tool.
The trick is to get two levers and put them on opposite sides of the sleeve, pivoting on the block and giving slight upwards pressure, but largely back and forth pressure, patiently many times, until a tiny bit of back and forth movement happens. Then just work patiently until that gap widens and it will come up. Doesn't take particularly long at all. Always works on XN1 engines, anyway..
The problem is not a lack of outward force made by some extraction tool.
The trick is to get two levers and put them on opposite sides of the sleeve, pivoting on the block and giving slight upwards pressure, but largely back and forth pressure, patiently many times, until a tiny bit of back and forth movement happens. Then just work patiently until that gap widens and it will come up. Doesn't take particularly long at all. Always works on XN1 engines, anyway..
can you diagram that Beano? i can't visualise it at all ...
It's pretty much what Greenpeace said above with two bolts at opposite ends of a diameter. I would also believe this is right. You can apply a huge amount of force to pull straight up or you can rock it side to side with Greenpeace's method incrementally until the rust or whatever bonds break and then it doesn't take much force to pull it out.
I would also suggest some freeze and release might be of help. I managed to get some really stubborn headbolts broken in the block to move that way.
Why pull out the sleeves anyway? I mean if they are to be replaced one doesn't need to take any care in extracting them, which opens a lot of other options. If they are to be reused, why take them out in the first place?
I would also suggest some freeze and release might be of help. I managed to get some really stubborn headbolts broken in the block to move that way.
Why pull out the sleeves anyway? I mean if they are to be replaced one doesn't need to take any care in extracting them, which opens a lot of other options. If they are to be reused, why take them out in the first place?
Get a couple of levers and rock the sleeve back and forth. It will take a little while to get it started, but persevere and keep going once you have got some movement.