Cylinder jackets / wetbliners. How to reseat.

[adrianbutter]

Interested to know, if anyone has experience.
Given that the offside head is off and looks fine to clean up and replace with a new water jacket seal ( that is the intent of the job), what is best for the cylinder sleeves ? They moved in removing the head. Can they just be left and will re seat as the head goes back, or can they come out easily to replace the lower seal ( do they slide back over the cylinder easily?) or can a new seal be stretched over the top and slid down, or can I leave seals but get some jointing compound in there?
I read that the engine has to be stripped to get the liners out, but I’m not sure I see that I see what is stopping them, or perhaps it easy to get them off and bugger to put back on.
Engine still in at this time.
Other option is stop before spending tons more hours and get a Hertitage/VEGE replacement.

Thanks!

[123-jn]

If you use a small hook such as a fishing hook attached to a drill bit you can hook the bottom seals off without taking the liners completely out, some people use a scalpel blade to cut them in the groove and then prise them out. The new seals will go over the outside of the liners and roll down and back into the grooves. I use some silicon grease on them. Its a bit of a fiddle but must be done if you don't want them to leak. Then same with the top seals (green) and a pair of new compression seals and you are good to go. Clean up the lip of the cylinder block and run a thin bead of reinzosil or the elring alternative around the inner groove of the new head seal, push it into place all round and run a 3/4mm bead of the same stuff around the mating face of the head seal. Now on with the head (make sure the compression rings are in place in the head with a small dab of grease and that the top of the liners is free from crud!! Hand tighten all the head nuts to the same tension keeping the head square on to the liners. Now tighten them up a couple of turns each in the correct sequence to keep the head square on. Now the same again until you can bring them up to torque . Do this very slowly so as not to get a false reading or wind up the studs. (Don't forget the yellow gunk under the head nuts!!) Now leave for 12 hours before filling with coolant, setting up the tappets and starting up. If the engine was running well then don't replace , I did this on mine when a head cracked. Only took 3/4 hours all in. The seals are a fiddle but very possible. The right head is easier than the left in situ as there is no nasty water pipe to get off and inter exhaust pipe etc.

[itchyfeet]

from the other post where you asked...

it's getting the piston pins back in with engine in that's hard because con rods won't stay where you want them ( rags can help to hold the con rod up then pull them out) and the fact that you probably don't have a vehicle lift so you are working at awkward angles, probably end up with neck and back ache for a week or two.

Personally I'd want to clean up both mating surfaces of the lower o ring, I have seen corrosion and many engines have had extra sealant added, there is often a lot of rusty dirt down there you can't guarantee a good seal by replacing o rings blind

People remove and refit barrels with engines in so it is definitely possible and maybe quicker if you have experience but as it fiddly it may take you longer than removing the engine, a gamble.

Great thread - lovely cut away.
I 've just had a water jacket fail and the off-side head has come off fine - but in the process has pulled the cyclinder jackets out a bit. Do these just re-seat themselves when the head is re fitted, or with sealant, or need to be replaced?(replacing would mean engine out etc).
Guess problem is knowing if the seal is still good without seeing - but engine was perfectly fine before - and as the rubber seal is buggered in various places, that was definelty the main problem.

Just interested really as will most likely replace the engine - but tempted to keep my original for a DIY re-build!

Thanks,
Ade

you would be mad not to replace the lower barrel seals even if thy had not moved, it can be done with engine in apparently but I wouldn't.

[123-jn]

Very True the mating surfaces are critical but you can see quite well if you pull the liner out as far as poss without pulling the rings out. Any doubt then it's best to take them apart. The problem I have found is that the piston pins are often too tight due to having hammered against the clips during service causing the bores to narrow slightly either end. This makes removal in situ a pig even if you can get the circlips out. I managed to use a slide hammer last time through the water outlet but it is tight. I suppose for the 4 hrs it will take to drop the engine it is probably worth it for a thorough job.

[ajsimmo]

... run a 3/4mm bead of the same stuff around the mating face of the head seal. Now on with the head (make sure the compression rings are in place in the head with a small dab of grease and that the top of the liners is free from crud!! Hand tighten all the head nuts to the same tension keeping the head square on to the liners. Now tighten them up a couple of turns each in the correct sequence to keep the head square on. Now the same again until you can bring them up to torque . Do this very slowly so as not to get a false reading or wind up the studs. (Don't forget the yellow gunk under the head nuts!!)

Just a couple of points to add:
Firstly, don't forget to fit your pushrod tubes as you fit the head! (There's no mention in this walkthrough.)
Torque of head nuts is critical. Clean all threads and run nuts down studs before fitting head to make sure there's no tightness to give false torque setting. Recommended torques (Nm) are 10 (to seat head squarely, check tubes are seating correctly during this bit), 40, 50 (the scary bit). I also do a 30 on the way. VW say don't use a click type torque wrench, but most do, including me. The deflection type are very inaccurate.
I wouldn't change bottom barrel seals without thorough cleaning first, and that's nigh on impossible with barrels in place. I remove them, clean and check everything, and refit in situ. As Paul says, with a lift it's easy, but on the ground it's 'orrible!


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[adrianbutter]

Much appreciated all - thank you!