Leaky flange: head to water rail gasket

[Mankee]

I've hit another stumbling block in my rebuild, just when I thought things were going really well.

 

Started filling up with coolant today after refitting the head and the water rail and noticed a big weep (contradiction of terms?) from where the water rail bolts to the head. Both surfaces were clean, new gasket used and both bolts cranked up with the front fixing fitted but not fully tightened, but it definitely doesn't look right:

 

http://images57.fotki.com/v1354/photos/8/42688/10523039/photo1-vi.jpg

 

The new gasket I fitted had part number PET10042, which is correct for the MG TF VVC 160 engine in the car. However, Caterham Parts lists PET10012 for the same gasket.

 

Can this simple difference be the solution to my problem? The other thing is that my car is a pre-96 and the coolant rail doesn't look like anything on Caterham Parts. According to the Rimmer Brothers site, PET10012 fits Metro GTi 1.4 16v, which is the engine that my car originally came with from the factory. And the Hoy Motorsport pages list PET10012 as "Head to Club Foot (91 onwards)".

 

It was all fine on my old engine (1800 non-VVC) and I'm using the same two bolts to secure the water water. Another thought I had was that the bolts might be bottoming out in the head. I'll pull them out another time and measure them; M6 x 20mm. Maybe I just need to splaf loads of instant gasket all over it, but I'd rather not...

 

Any thoughts appreciated. This rascal of a little car is doing my head in!

[Wrightpayne]

Mankee

 

Hi - lots in the archives on this concerning the bolt length and front fixing. Mine seeped due to the front fixing being too tight against the head IYSWIM. Needed to bend the pipe slightly to move the fixing plate off the head. Others experience the opposite where there is a gap and needs a washer to stop the front fixing twisting the waterway flange off the head.

 

Ian

[Englishmaninwales]

YHM

[Mankee]

Thanks for the reply guys. I had another fiddle a short while ago and the original bolts weren't too long. I replaced them with a pair that were longer and they didn't bottom out, but still the same problem.

 

Going to try the washer(s) tomorrow on the front fixing and maybe double-gasketing. I can see that the problem is in the area not secured by one of the screws, so maybe it's a warped flange. Bummer. 🙆🏻

[SLR No.77]

Common problem ... use a small bead of Loctite blue silicon adhesive sealant (RTV) on both sides of a new gasket and it'll seal perfectly

 

Stu.

[Mankee]

Removed, recleaned and refitted with two gaskets and a helping of Loctite 5699. Hopefully it'll be nice and solid by tomorrow afternoon when I'll try filling the thing with coolant again.

 

The front mount is still a worry though, as there's no way it'll line up with the hole in the head without a lot of force, which probably didn't help with the flange sealing.

 

Sounds like a bodge, but is there any harm in leaving it unattached and just relying on the two flange bolts at the other end? It feels very solid.

[oilyhands]

In which dimension is it misaligned? is it too high, too low, too far away from the head, too far forward, too far back? It's not really safe to leave it floating about.

 

Oily

[Mankee]

Hi Dave.

 

Bugger. The bracket is about half the bolt hole too low and it is also a few mm away from the head. The latter isn't a problem as I could use a washer or two to pack it out. The former is a bit of an issue though.

 

Maybe I need to pull it all apart again, stick it in a vice and give it a tweak to bend the rail upwards slightly. Or weld on a slightly longer tab. Or try and elongate the hole in the existing tab. I wouldn't mind seeing if the flange leaks before removing it again, though.

[oilyhands]

It's a common problem.., just elongate the holes a little and use flange bolts, then as you suggest a couple of packing washers between the front mount and the head. I've done a few that way with 100% success so far.

 

Oily