‘74 DS Resto

KAndy

New member
Thanks Budge, a great link which gave me plenty of welcome guidance over the weekend.
No luck with removing the cylinder liners, they are in for good, the bottom of the tubes are flared out wedging them firmly in place. I bent David’s tool trying to extract one- couldn’t even twist them in place. There is no ‘internal lip’ on them from the ring ware so my updated plan is to simply hone each one and replace the rings…
In the meantime a few little jobs this weekend:
Clean
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new boots on drive shafts;
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Clean bits and bobs such as mirror assembly;
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slow but steady progress…
 
I'm not sure how the liners would become flared at the bottoms unless someone has beaten the stuffing out of them in the past and gave up after doing damage???? Anyway, if you are planning to not remove the liners, at least make sure their tops are not below the level of the block face. If they are, the head gasket might fail prematurely and you really should remove them and replace the seating gaskets. Supposedly the connecting rod bolts should be replaced at overhaul, but see what the experience of others has been if they reused them.

Be careful about honing the bores as honing incorrectly can result in problems such as a 'wet' (oily) engine, which could be worse than refitting slightly worn rings. If in doubt, don't, or seek advice first. The ring manufacturer may provide guidance on the honing recipe. You can tell a lot about the state of the bore by pushing a ring down and measuring the gap at different points as this can reveal barrelling. If you can still see all of the factory honing, that's a good indicator the bores are still quite good.

You'll need to remove the triax from the driveshaft to replace the inner boot. It wants a press or a suitable extractor as shown in the manual. Look for wear spots where the three rollers touch the insides of the triax casings. Ligarex is used to hold the boot in place.
 

KAndy

New member
Yes David, appears that was what was done, you can see the flaring in this photo:
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very annoying, and its the same on all four liners.
View from the top is not too bad:
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the liners actually sit quite flush:
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driveshafts came up well:
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the local garage is very helpful letting me use their press, and my strapping skills are improving…
 

Budge

Member
The danger with someone having hammered away at the cylinders - but not removed them - is that the seals around their bass are compromised and coolant can leak into the sump. In your case, the car was running before you dismantled it, so it would seem you don't have that problem. If you really wanted to replace the cylinders, you could have them pressed out at the garage? Applying a bit of heat to them in the process would probably help their journey.
 

Buttercup

Member
I reckon I'd cut the cylinders out and fit new ones.
The flared bottom is not going to keep the piston straight near bdc, who knows what that will do to the life of the piston or rings.
If the bottom part wasn't needed, the designer would not have put it there.

To remove them I would not apply heat. The co-efficient of expansion of the sleeve is probably slightly higher than the block, so it will actually get tighter with heat.
You could try a can of "Freeze-It" spray to loosen them.

I would probably use an angle grinder with half worn 1mm disc to remove the flared skirt, then make 4 or 5 cuts up the inside, so the barrel can shrink as it comes out.
You need to be somewhat skilled with an angle grinder, to do it safely, and without touching the block.
Skilled angle grinder technicians are around.
Another tool that could do the job is a die grinder, with carbide burr, to cut deep grooves up the inside.
OR you could get a machine shop to bore them until they are very thin.

Either way I reckon they need to come out.
 
Use a piston to push a ring squarely down each liner and measure how the gap changes at several positions. See if you can fit a thin feeler gauge between the ring and liner at any point. Pay special attention near the bottom of the liners to check if they are out of round or mushroomed inwards from the beating they had previously sustained. Refitting one of the pistons/rods at BDC will let you see how far down the skirt of the piston travels and what portion of the bottom of the liner is not so important.
The photos look to show some scoring and marks you might see if a ring had rusted to the bore at some point in the past. Those liners do look past their best. Did it have reasonable performance and cylinder compression before dismantling?
 

KAndy

New member
Use a piston to push a ring squarely down each liner and measure how the gap changes at several positions. See if you can fit a thin feeler gauge between the ring and liner at any point. Pay special attention near the bottom of the liners to check if they are out of round or mushroomed inwards from the beating they had previously sustained. Refitting one of the pistons/rods at BDC will let you see how far down the skirt of the piston travels and what portion of the bottom of the liner is not so important.
The photos look to show some scoring and marks you might see if a ring had rusted to the bore at some point in the past. Those liners do look past their best. Did it have reasonable performance and cylinder compression before dismantling?
Thanks David, the first cylinder was down in compression, the others were reasonable. I still am surprised that she ran, and started so easily given the condition of the engine.
Agree the liners must come out, I’m just taking a breath before I tackle it again.
Thanks all, Andy
 

KAndy

New member
Just needed a quick easy job for a change, so I tackled the Pressure Regulator with a kit from Citroen Classics.
Easy job, plenty of info around to guide you, this link is a good place to start.
https://ds-restoration.blogspot.com/2018/02/pressure-regulator-strip-and-rebuild.html
It all came apart easily (need an impact driver to start the two screws holding the side chamber) two seals and ball bearings inserted and I’ll tighten it up once I replace the two screws from the side chamber (best replaced).
Spot where I got to use one of Bob (buttercups) bolts…
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Buttercup

Member
What is the blue sealant for?
There is an O-Ring inside to seal it.
Please don't apply sealant!
Aweful messy stuff. Completely unnecessary.
 

bleudanube

Member
Is that the number of shims you had in it? 4 for the main spring and 4 for the side spring?

I had 6 in the main spring, so I was assuming that would be to adjust for the Safari settings for the cut in/out pressures? And so think it was 4 for the side spring…
 

KAndy

New member
What is the blue sealant for?
There is an O-Ring inside to seal it.
Please don't apply sealant!
Aweful messy stuff. Completely unnecessary.
Blue was there.
l have not, and don’t intend to apply anything apart from a good clean and the new o-rings and ball bearings.
 

KAndy

New member
Is that the number of shims you had in it? 4 for the main spring and 4 for the side spring?

I had 6 in the main spring, so I was assuming that would be to adjust for the Safari settings for the cut in/out pressures? And so think it was 4 for the side spring…
Yes, that’s the contents as dismantled. 4 in each.
 

faulksy

Member
I'm assuming each pressure regulator was bench tested and adjusted by the factory which would account for the difference in shims. It's also possible a regulator has been swapped on from a different car. If you're feeling brave you can make up a jig to test it.

Cut in should be 140-150 bar
Cut out should be 165-175 bar

A 0.3mm shim in the cut in chamber changes the pressure by 3 bar and a 0.70mm shim in the cut out chamber changes the pressure by 7 bar
 

bleudanube

Member
Cut in should be 140-150 bar
Cut out should be 165-175 bar

A 0.3mm shim in the cut in chamber changes the pressure by 3 bar and a 0.70mm shim in the cut out chamber changes the pressure by 7 bar
Cut out is which one? The main or the side chamber? So if I had 4 thin shims = 12bar and 6 thick ones = 42bar… that’s 30 bar difference (140 to 170 bar). Just need to know whether it does cut in at the right pressure…
 

faulksy

Member
I think cut out is the one one the side.

The pressures for 1969/1970 cars are different.

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The older aluminium regulators are different again
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If you do that, the crank must be removed first to avoid possible splatter/arc damage. Before you engage in destructive removal of the liners, you need to decide whether you are prepared to buy a new piston/liner set? Also whether it is essential to replace them or whether you can make the best of what you have with new rings. Do some careful measurements before going further.
For a late 23, the 62Bar welded accumulator suits, but there are some earlier exceptions as for the regulator settings. 62Bar is a nominal static pressure and you will find the data allow a tolerance of something like +5/-30 Bar. If the regulator worked OK before you took it apart, the odds are it will work OK after the re-seal. However, bench testing it would be a good idea.
 
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