I may be totally off here, but one method which i have heard about for pulling the sleeve from bellow is to fabricate a plate with exact diameter of the piston, then weld it along the bottom of the sleeve and bore a hole in it to pump grease in you can put around 10-15 tons of pressure on that sleeve, but theres a catch, the hydraulic pressure will also be pushing the sleeve against the wall of the block cleating more friction. i had a dodge intrepid which i used this method to free the seized piston with i screwed a grease gun hose into the spark plug hole in the cylinder head and pumped away at it. it unstuck that piston AND managed to unstick two more pistons at the cost of warping the crankshaft badly. LOL

WOW...You guys are terrific! I had no idea this posting would generate such response.

I used to remove Alfa Romeo wet liners on a regular basis in the course of major rebuilds and a few times in the car. We were lucky to own some very high quality factory tools consisting of thick case hardened discs with machined steps and a tempered fine threaded shafts that applied pressure from the center. I hardly ever used them once I learned a few time saving tricks. These liners were also unbelievably tight, requiring massive forces, the special tools and tons of time. On the other hand, if the raw block was placed on the floor, then carefully and uniformly heated with say an oil fired salamander they would almost always drop out on their own accord like magic. Although I have not held a Mercedes liner in my hand, there are two major differences that come to mind. The Alfa blocks were all aluminum and the liners were much thicker. Before every engine rebuild after the liners were removed, the blocks were hot tanked tanked and given an align bore check by my trusted machinist. Not once was a block ever warped using this method but I'll spare you the details about the consequences of using other methods, especially the hydraulic press.

On a number of very rare vintage blocks which had often been left outside or obtained from old seized motors, liners were virtually welded to the blocks due to water, rust, and galvanic action. When original piston-liner sets were not available, used liners could often be bored by a competent machine shop to match 1st or 2nd piston oversizes. Trashed liners would always have to be painstakingly extracted using any number of methods. These included running a die grinder along the length of the bore, applying uniform heat to the block, chilling the liners with compressed air or nitrogen, selective fracturing of the cast liner, working penetrating oil into the press fit area, etc. Another important trick I learned along the way was to always favor using any method to pull the male member of the press fit into the female member as opposed to pressing. This runs counter to most procedures since it is often not possible, however, on liners this can be theoretically accomplished during extraction, which is always far more difficult than insertion. As some of you mentioned, removing liners using a hydraulic press will usually require massive pressing forces since the male member tends to mushroom.

Although there were some opinions voiced about the need to bore and surface plane Benz liners after press fitting, this was never required on other engines I encountered although it is commonly addressed in most good factory workshop manuals. According to references in the service bulletins from MB's OE supplier, Kolbenschmidt (KS) , each piston liner assembly contains the required shim/sealing ring to assure proper deck height. I would assume that when these piston/liner sets are installed into bare blocks additional machining would not be necessary. This situation could change if dirt, corrosion, incorrect seals, or imperfect press fits alter these dimensions.

Now for all the if's, and's and but's that could make or break the feasibility of this operation. Assuming you have a spare block with liners and a pair of well machined and oil quenched (hardened) upper and lower threaded plates, would it not be possible to heat the block and extract the liners without deforming or marring the bore?

If so,you might be able to salvage several usable liners and pistons during the process of a complete rebuild or teardown. These of course would be standard bores and would match the mating pistons exactly or for that matter any other used piston from the piston class designated by the factory stamping on the block. Hypothetically, if the bore tolerances were ok, these could be ridge reamed, honed and used with matching pistons after installing fresh rings and could always be used as individual substitutes in an emergency ie:cracked rings, liner cavitation, piston defects, etc (BTW, I have a spare motor sitting in the shop that meets this description thanks to some guy who overheated his 603 engine ruining the ring tension but showing a decent bore) We all realize that there are new liners as well as piston/liner sets, but let's ignore this fact for the time being, since it will only compound other variables such as differing bore tolerances, piston weight variations, etc.

Now, one day we yank the head on our car for a gasket replacement only to find the dreaded sight of a single liner with deep vertical scoring, most likely the result of broken rings and the hidden cause of irritating blowby and oil consumption. What would you guys do in a situation like this?

Since the liner is history and other alternatives range from risky gambles to outrageous amounts of time and money, wouldn't it be dandy to have the option of dropping the pan, removing the piston, and doing an R&R on the liner? I have heard of very reputable diesel shops using the weld bead method one of you mentioned. Let's say we go one step further by doing the following:
1. Hacksaw the top of the junk piston, fit an O ring in the ring land and use it as a plug for bottom of the liner.

2. If needed, use the best combination of cutting, fracturing, grinding, etc then bead weld but with the following addition.

3. Near the top of the liner, purposely leave a gap in the weld line. At this point carefully center a sacrificial washer, old piston ring, etc. using a vernier caliper to keep the depth more or less equal then weld a few spots along the perimeter above the ring. This will serve as an anchor point for PULLING from below using the lower disc of our special tool. Notice that this is not mating the lower edge of the liner like most conventional tools. It will require a recess cutout to accommodate the welded bead.

4. Center the upper disc with the threaded rod (found on many gear or bearing pullers) and a machined recess for the liner and thread into the threads of the lower plate. This should pull with enormous force but owing to the design of the anchor, it will act to shrink the outer walls of the liner in proportion to the force applied as opposed to mushrooming the liner thereby avoiding many risks to the block from warping or cracking, using a hydraulic press.

Installation of a replacement liner should be much more straightforward although you would loose the ability to get a decent pull. Gently heating the block from below for a couple of hours as well as cooling the liner would greatly reduce the force required. If I'm not mistaken, for all metals there certain values defining their coefficients of expansion and contraction but all have a narrow range of acceptable engineering tolerances for press fits. After this point the metal will deform or form cracks. Of course knowing Mercedes, they always seem to enjoy taking the limits of force to the most absurd levels. This is what scares me, but as we all know there have been many clever solutions revealed in this forum alone. This may or may not be one of them, but I'd be willing to bet it's doable and certainly been done before.