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AQUAR
30-08-2015, 07:20 PM
In an earlier thread I mentioned my Magna TP was leaking a fair bit of oil at the half moon seal.

Today I pulled the rocker cover of the engine and found the half moon seal to be as hard as rock (not surprising therefore that it was leaking like a sift!).
The gasket was also hard and definitely not reusable.

http://i.imgur.com/3CuzBSY.jpg

What did surprise me was that the rocker cover had a silicon bead in the bottom of the gasket slot. It was a very neat bead but some of it lifted and broke away whilst cleaning the cover.


http://i.imgur.com/HP9tgmh.jpg

Could this silicon bead be an original factory seal for mating to the gasket?
Or is this a bodgie that was done to re-use an old gasket?

I asked the mechanic down the road and he believes I should not use any sealant except at the half moon seal (as per coldamus advice) and in the corners of the camshaft seals.

Since this silicon bead was damaged I had to removed it all from the slot anyway.
But the dilemma now is "should I create a new silicon bead or just use the gasket without this silicon bead".

Has anyone come across this silicon bead in the Astron II rocker cover gasket slot before?

Personally I can't see why the silicon bead is needed.

So - to bead or not to bead????

MadMax
30-08-2015, 08:20 PM
No bead needed, but you may need to use some sort of adhesive to hold the gasket in place when you refit the cover. Up to you - if the gasket starts to drop out when you turn it over to drop back on the engine, get out the silicon or any non hardening gasket goop you have.

Small dab of silicon in the 4 spots (as per workshop manual), bolt up to right torque(*), drive on.

Probably need to replace the two bungs under the hold down bolts too.

(*) Excessive torque can distort the bits they bolt into and damage/seize the cam.

AQUAR
30-08-2015, 08:44 PM
Madmax - getting ever so much closer to the 10,000 milestone!


Those 2 bungs under the hold down bolts are a strange V shape.
The hold down bolts are only tightened to 7Nm (not much - especially with only 2 bolts to tighten the cover to the head!).
I'll check to see if these bungs are still available (maybe Repco?).

magna buff
31-08-2015, 04:51 AM
#
cleanest engine bay I have seen in a long while


any tighter you may crack the cover

I have seen the rocker bearing split where the rocker cover bolts too

even a rocker cover crack at the holding bolt area

if it leaks without sealant the cover may be warped

I had a car fail a roadworthy because I filled too much silicon
into gasket and the rocker cover areas

AQUAR
31-08-2015, 07:06 PM
Thanks Buffy.

I find it amazing that despite not feeling the best, you can still push on and provide help here.
I will assemble without sealant except on those spots where a dab is required.

If it leaks I can always try again with more sealant, with the silver lining that at least I can use up that tube of expensive RTV (before it goes off!).

Have ordered the rubber seals for the valve cover hold down bolts from Mitsu and Repco (gives me a spare set for the Sigma!).
Didn't want to take a risk with stuffing the valve cover as these seals were also rock hard.

Whilst waiting for these seals to come in I noticed the accelerator cable sleeving was split.
I repaired that by covering the split with a plastic sleeve filled with a bit of epoxy and wrapping the whole patch in self fusing tape.

Meanwhile, when looking at how the accelerator cable was connected to the pedal, I noticed that the boot between the brake pedal and brake booster was quite moist with an oily looking drop hanging off it.
Don't think it was brake fluid as it felt quite greasy (hoping its not another problem!).
Have dried it up and will keep an eye on it and the brake fluid level.

Would brake fluid travel through the brake booster?


Aren't old car fun!