I've been losing the battle to prevent my Cam Shaft Covers from leaking and I'm asking for some advice here. After the engine and head were rebuilt I used Cometic seals on the covers. They say they do not need any sealant so I didn't apply any. They leaked profusely. Took the covers to the machine shop that rebuilt the head and discovered the that both covers were slightly warped from age. Had them milled flat and used copper spray sealant on paper seals this time. They still leak! I did use silicone on the right side end around the tachometer generator both times and it leaks there and on the left side end as well, I did not use any sealant on the rubber 0-ring on the right side since it's very tight fit. There are some minor leaks along the edges as well which I suppose is a failure of the copper sealant.

My question is what techniques and sealants have worked to stop them from leaking? I've got a tube of Hylomar AF that I plan on using on new paper seals. Any suggestions on what works on the rear portion of the covers to prevent leaks? I'm putting new rubber o-rings on both sides and the half round seal on the tach generator - Again!

Third time is a charm hopefully...

 

Hylomar on both sides of the paper should work. I didn't have any and I used a smear of synthetic marine grease, which also worked fine. Apart from the paper gasket, I think later cars used a rubber gasket which might be better at taking up clearance. It's most important not to overtighten the retaining nuts as it will distort the cover; a socket with the lever held close to the socket is about right (or no lever at all for a gorilla grip mechanic) . Finally, are you sure the leak is from the cover to head joint and not from below the nuts? The copper washers should be annealed

 

Thanks Peter. I just pulled the covers and the leaks were from in between the gasket and covers not the gasket and engine. For some reason the copper sealant did not adhere to the cam covers. It appears that both of the o-rings on the tach generator and the blanking plug on the exhaust cover did not seal well also. There was a little oil on the copper washers but oil did not escape onto the exterior of the covers. The half round seal on the intake side did not leak.

When I get the new seals I'm going to use the Hylomar on the o-rings and the paper seals since it is a non hardening sealant. Silicone sealant on the half round seal as I did before. I will anneal the copper washers as well

Any other suggestions? This has been so frustrating since I just want to drive the car and not leave oil stains wherever I go.

Next repair is the power steering pump. It is suddenly leaking like a sieve!

 

I'll just use the standard gaskets with a coating of Hylomar on one side and grease on the other, to aid future removal, on all car and bike engine covers. If it has seeped oil when I next check after a few miles, I'll use clear universal builders' silicone sealer (sparingly) and try again. I always tighten these sorts of covers gradually, from the centre outwards, and go round about three times to prevent distortion. The cam covers keep clean and dry on my '66 S Type - it's the rest of the car that's the problem!

We're usually fighting a battle against previous owners and have to do what we gotta do.

Ray

 

When I put my motor back together I used Permatex Ultra black sealant with the standard paper gaskets. I put a light smear on both sides after cleaning the surfaces and knocking light nicks off with a fine file. I have never used Hylomar so I am not against it, Its just not easily available near me. Also used fresh copper washers. I agree that "just past finger tight" should be the torque setting. That said, I just went out and checked "before I start spouting again" and I do have some minor seepage at the back ends. At the moment I am not sure where exactly it is coming from, it could be the oil gallery tubes or the gasket. If it is the gasket, that is the only place it is leaking. Good luck.---

 

I usually re-anneal my copper washers, - hook several of them on a bit of welding rod or wire, heat up with my gas torch until they're red and then drop them in a handy bucket of water if I haven't managed to kick it over. It's best, I find, to anneal even new washers if it's a troublesome leak because they tend to go hard in storage.

Ray