Simon's new Xantia V6 and Leaf blog

[Stickyfinger]

http://windscreens4sale.co.uk/product/w ... cars-vans/

[xantia_v6]

http://windscreens4sale.co.uk/product/w ... cars-vans/

OK for glueing in a bonded screen, but the wrong stuff for a scuttle trim, unless you are sure that you will never need to remove it again.

[CitroJim]

Oh gawd, this whole scuttle sealing issue now seems to have become a minefield

[white exec]

Easy, Jim: If you want the part to be easily removable (pull-off without damage), use silicone, possibly just a few blobs. Pull, and it will give way. Good for gap-filling/waterproofing, but not for heavy anchorage.
For permanent adhesion, or parts that have a tendency to spring or stand off, use PU. Windscreen glass is invariably secured with PU, as the glass can be part of the upper body rigidi

[CitroJim]

PU might still be the best then Chris as in my experience silicone sticks well tot eh scuttle plastic but is very reluctant to hold on for any length of time to the glass...

[Stickyfinger]

With the PU, I would only use a very thin bead at the edge.

[xantia_v6]

The last time I glued a scuttle trim I used the Loctite silicone usually used for ES9 sumps and cam covers. It seemed to stick adequately.

[CitroJim]

The last time I glued a scuttle trim I used the Loctite silicone usually used for ES9 sumps and cam covers. It seemed to stick adequately.

That's good to know... I once used some of that in a toilet cistern and it's still good now... Top stuff...

[Stickyfinger]

To be honest, the VAST majority of times any adhesive like silicon does not work the fault is normally preparation. Look what is done in a "production facility" to ensure total removal of contaminants at the adhesive process point. A wipe with a clean cloth even if it has some ISO-p on it is rarely similar. Some very strong materials are used, adhesion promoters, heat, removal of surface and atmospheric moisture etc. These conditions are hard to achieve for the DIY application in a garage, less so outside on a winters day even if it is dry.

[lexi]

There is also the modulous of the silicon or PU to consider. Most window and light panel construction has high movement, so needs low modulous.
If I am bedding something that does not need adhesive strength, has high flex movement and needs to be water tight, I use butyl compound. It never goes hard and is easly removed, though messy. As long as there is no traffic on it or anyone touching it. Threshhold bars and caravan skylights are an example of it's use. A good cheap version of Buty,l is "no nonsense" gutter sealant from B&Q or Screwfix. As a non- setting compound it allows cast iron gutters to move without binding, which can cause cracking. It does, however rely on a thick bed with no air getting in to keep it sticky. If you put a skin on which is exposed to air, it will dry and harden..........no use.

[DHallworth]

I want something that's going to stick my scuttle to the windscreen like s**t sticks to a blanket as I DON'T want to be doing this job ever again.

David.

[Mandrake]

So the car seems to have been running fine since the thermostat replacement, with the temperature gauge behaving itself as expected and the engine running nicely. However today for the first time in the week since I replaced the thermostat I got a chance to re-check the coolant level properly.

I couldn't check it during the week as in the evenings the engine would be hot and in the mornings I didn't have time!

I was a bit annoyed to see that the level was right at the bottom of the expansion bottle - not quite visible but it wasn't far below as it appeared with a very small amount of coolant added. (Naturally the non-functional coolant level warning sensor in the S1 failed to alert me to this fact! ) In total I would say I added about 200mL to bring it up to the half way point which is where I usually set it when its cold - especially when ambient temperature was only 4 degrees.

Should I worry about a possible leak ? Some kitchen roll paper has been sitting up under where the matrix was previously leaking for the whole week and it has not caught a single drop from the matrix, compared to the half soaked sheets that were happening daily before the Forte originally went in, so I'm pretty sure the matrix is not leaking.

I only bled the system once, cold, during initial refill, so is it possible that there were still some trapped air pockets that worked their way out over the week and thus caused the visible level to drop ?

There doesn't seem to be any leak at the radiator drain or bleed taps, so if there is a leak somewhere it would have to be either at one of the three radiator hoses that was disconnected, (which seems unlikely as all the hoses looked good and I cleaned up the stubs on the thermostat housing) at one of the bleed screws, or at the interface between the thermostat housing and engine block - I did not use any additional gasket sealant on the flange of the thermostat as it has a thick rubber flange that doesn't seem like it would need it, and the original thermostat didn't have any additional sealant.

Should I just watch it over the next week to see if the level drops again before deciding whether there is a real leak or whether it was just trapped air ? The thought of having to take it all apart again to try to find a tiny leak makes me want to cry so I really hope its not that...

[white exec]

Bleeding should be done by bringing the engine up to full working temperature, and letting the fan(s) cut in a couple of times. As well as the bleed screws, squeeze any available large hoses to help displace any trapped air. Then, with the cap off, allow engine to completely cool, and top up to correct level. After a day or two of driving about, level should stabilise.

An alternative way to top up (after doing all the proper bleeding) is to deliberately overfill the expansion tank (ie almost to the top) and allow the engine to expel excess coolant over a couple of days' use. This allows you to establish the tank's natural coolant level, which may/may not correspond to textbook. (In the case of the 2.5 XM, the stated stable coolant level is much lower in the tank than the book states; coolant expansion is significantly underestimated!)

When all that is done, put some paper or cardboard under the car, overnight, with rad cap off (to prevent any vacuum) - should help pinpoint any leak. Hopefully there isn't one!

[Mandrake]

Bleeding should be done by bringing the engine up to full working temperature, and letting the fan(s) cut in a couple of times.

I did do that - after filling up and closing each bleed screw when it dribbled I then let it run with the cap off until it warmed up and the fans cycled on a couple of times.

As well as the bleed screws, squeeze any available large hoses to help displace any trapped air. Then, with the cap off, allow engine to completely cool, and top up to correct level. After a day or two of driving about, level should stabilise.

I didn't get a chance to check the level after it had fully cooled down again, as I finished late in the day it would have been the following morning before it had truly cooled down enough to check the level properly.

An alternative way to top up (after doing all the proper bleeding) is to deliberately overfill the expansion tank (ie almost to the top) and allow the engine to expel excess coolant over a couple of days' use. This allows you to establish the tank's natural coolant level, which may/may not correspond to textbook. (In the case of the 2.5 XM, the stated stable coolant level is much lower in the tank than the book states; coolant expansion is significantly underestimated!)

Indeed - I think the natural coolant level on the Xantia V6 is quite a bit lower than you'd think - about half way up the stalk in the middle. If you set it any higher than that the expansion is enough to expel coolant through the cap.

When all that is done, put some paper or cardboard under the car, overnight, with rad cap off (to prevent any vacuum) - should help pinpoint any leak. Hopefully there isn't one!

Not sure that paper/cardboard would show anything - if there is a leak I suspect it would only occur when hot and under pressure. And it could be quite a small leak that would dribble onto a hot part of the engine and evaporate before it could find its way to the ground.

[CitroJim]

Simon, I always find the coolant level seems to drop quite significantly after major work on the cooling system involving a total swap of the coolant...

I watch it like a hawk for a few days afterwards.

My theory is that an initial bleed does not remove all air and some pockets remain that only get blown out after a few days of use and then properly fill with coolant - hence the fall in level...

Pleased to hear the temperature is now stead and the job has been a success