Oil leak from dry sump conning tower cap

[jimmyslr]

My car has recently developed a small (but messy/annoying) leak from the cap on the top of the dry sump conning tower. The only change I can see/feel is that there seems to be some play in the revolving top bit of the cap (that holds the hose to the catch tank) that wasn't there before, hence, although done up as tight as possible it feels like it could be tighter.

 

I have looked at the O-rings I can see (one on the conning tower at base of screw thread and one inside top of cap) and they look fine. Is there another seal between the cap and the revolving top bit? I tried to remove the "spout" that feeds to the catch tank so that I could disassemble and check for a further seal but it in not budging / impossible to get leverage on. Any thoughts?

 

In the realm of things a minor problem but makes everything messy!

[Shaun_E]

Are all the allen bolts that hold the top of the conning tower on all done up tightly?

I don't completely follow your description but on my car the conning tower casting has a machined section bolted to the top using 6 (or eight?) allen bolts. This machined section has the fitting for the hose to the catch tank and an internal thread for the cap to screw into. Possible leaks could be due to:

1) cap not done up tight

2) allen bolts loose allowing oil to get out between the conning tower casting and the machined section

3) hose to catch tank not tight on fitting - there should be a jubilee clip on here.

 

Yellow SL #32

[EvoDunc]

I've the same problem on my SLR. Oil sprays from between the cap and the take off hoses which lead to the catch tank. I went to Caterham and they have suggested changing the rubber o ring in the cap and although they couldn't supply me one I was told theres nothing special about them so should be able to get them from any decent automotive place. It does appear this can be only likley cause, I haven't any allen bolts holding the top part of the tower on though, only 4 holding the tower to the bell housing. Changing the seal does look like a fiddly job so have yet to tackle it.

 

Hope that helps,

Dunc.

 

 

[Shaun_E]

Looks like they've changed the design then - mine is a recent purchase.

 

Yellow SL #32

[EvoDunc]

Mines a 98 car (SLR Number 41) so old and cheap! 😬

[jimmyslr]

Thanks chaps. Mine is a 99 SLR, but the earlier design it would seem. I employed brute force and got the "spout" (I am all over the techy words) off and now have the scratches to prove this - very iffy design. There is another O ring hidden within the cap. I have replaced all such offending rings, although they seem of very small cross-section so some bastardisation of the rings (from my "every O ring you would ever want" selection - ho ho) was required.

 

It is now fitting snugly but it remains to be seen whether my efforts with a stanley knife and an over-fat O ring prove oil tight.