Page 1 of 1
Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 8:45 am
by Rose taupe
Yes I have the dreaded oil leak coming from the tappet chest and I would like to know from anyone who has replaced these gaskets, what is the easiest way to replace them, ( do I need to remove the manifolds )
Thanks.
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 10:03 am
by les
You should be able to get to them. Why not try before dismantling anything else, if you can’t, then yes remove the manifold.
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 10:11 am
by svenedin
You don’t have to remove the manifolds but you need to be able to see what you are doing so some illumination from underneath is useful. It’s a very common place for a leak. Don’t over tighten the bolt and remember to clean up the mating faces. There’s a rubber washer round the bolt under the cup washer too and oil can leak there as well as from a failed gasket.
Stephen
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 11:52 am
by Rose taupe
Thank you for the advice, I shall give it a go.
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 12:00 pm
by philthehill
The rubber washer under the cup washer is only fitted to 1098cc 'A' Series engines. The earlier 'A' Series engines had a plain fibre washer.
The cover bolts are different lengths for the concave and convex tappet covers.
Not all the parts are interchangeable.
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 12:30 pm
by mike1864
I'd get the gasket securely fitted to the cover first, using gasket sealant. I've found that if you fit it to the head first, it can misalign into the cover's groove.
This happened to me once, with the gasket twisting 45 degrees along some of its length, and oil leaking out from the resulting edge contact, and spraying all over the engine (and France!).
I only discovered the cause when a generous top-up (at Dover) dribbled straight out the offending section.
Also, don't rely on an old gasket. The cork may have dried out, and they can shrink so much that they clearly won't fit!
And - unless recently done - I'd check/adjust the valve clearances while you've got the access.
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 12:56 pm
by myoldjalopy
mike1864 wrote: ↑Tue Jun 11, 2024 12:30 pm
I'd get the gasket securely fitted to the cover first, using gasket sealant. I've found that if you fit it to the head first, it can misalign into the cover's groove.
This happened to me once, with the gasket twisting 45 degrees along some of its length, and oil leaking out from the resulting edge contact, and spraying all over the engine (and France!).
I only discovered the cause when a generous top-up (at Dover) dribbled straight out the offending section.
Also, don't rely on an old gasket. The cork may have dried out, and they can shrink so much that they clearly won't fit!
And - unless recently done - I'd check/adjust the valve clearances while you've got the access.
Yes, but the OP is referring to the tappet chest gaskets, not the rocker cover gasket......
Re: Tappet chest gasket replacement
Posted: Tue Jun 11, 2024 12:57 pm
by svenedin
mike1864 wrote: ↑Tue Jun 11, 2024 12:30 pm
I'd get the gasket securely fitted to the cover first, using gasket sealant. I've found that if you fit it to the head first, it can misalign into the cover's groove.
This happened to me once, with the gasket twisting 45 degrees along some of its length, and oil leaking out from the resulting edge contact, and spraying all over the engine (and France!).
I only discovered the cause when a generous top-up (at Dover) dribbled straight out the offending section.
Also, don't rely on an old gasket. The cork may have dried out, and they can shrink so much that they clearly won't fit!
And - unless recently done - I'd check/adjust the valve clearances while you've got the access.
Yes but if it’s a 1098cc later engine the tappet chest gaskets are neoprene and much better than cork.
Stephen