6.5 TD Valve Cover

[sfox]

I just did my passenger side valve cover gasket as it was leaking terribly. Did it once with gasket, it leaked. Doing it again with 'the right stuff'. Also changing oil. Perhaps a strange question but would it be possible to add at least some oil through the valve opening in the valve cover to check for leaks before reassembling? I would love to verify I am leak free before I have to do this again. I would not be so cautions but one of the the valve cover bolts was stripped and had to be tapped so I want to make sure all is well if possible before reassembly since I have turbo and manifold off so everything is nice and accessible.
Thanks for any input.

[Yukon6.2]

Hi sfox
No you can't test it for leaks.Using the gaskets will result in leaks as you found out.The best you can do is make sure both surfaces are clean and use a good sealer,like the stuff you used.You might curse it when you go to take it apart.Usually a good automotive RTV silicon will do the job.Don't tighten the bolts all the way just enough to get a good squish on the silicon,let it set up and then tighten the bolts some more.
Good luck
Thomas

[DmaxMaverick]

Hi sfox
No you can't test it for leaks.Using the gaskets will result in leaks as you found out.The best you can do is make sure both surfaces are clean and use a good sealer,like the stuff you used.You might curse it when you go to take it apart.Usually a good automotive RTV silicon will do the job.Don't tighten the bolts all the way just enough to get a good squish on the silicon,let it set up and then tighten the bolts some more.
Good luck
Thomas
That's the key to a good seal, along with clean sealing surfaces. Do this, and there won't be any leaks. Gaskets leak, as you've found.

[sfox]

I was afraid of that. I know it is clean I am just concerned about that bolt. If one was to add oil through the Crankcase Decompression valve opening would it not simply drain back down into the old pan as if oil was being pumped there? Or could that damage something I am not thinking about?

[DmaxMaverick]

You could do that, and you are correct, mostly, but it won't tell you much. If it leaks under that condition, it would be a relatively large leak, one that would be huge with the engine running. The gaskets that leak, tend to leak over time and heat cycles, not just run out through a fresh sealing. Hot oil pulsing with the crankcase pressure will act/leak very differently than cold oil just passing along the seal. If you did a good thread repair, it should not be a problem. There shouldn't be much torque on the bolts. If you're concerned about it loosening, remove the bolts before the final tightening, and use some sealer or thread locker on the threads. Give it time to set well. The "right stuff" will do it's job as long as their is at least marginal fastening tension, you don't try to "build" a gasket with a too-large bead, and the surfaces were clean. It also helps to true-up the cover seal surface and peen the bolt holes if they have been distorted (usually from overtightening). If the cover is significantly distorted, it can prevent even torquing along the sealing surface, and will result is leaks, sooner or later, gasket or sealer.

[Robyn]

Be sure you clean the mating surfaces with Brakekleen, allow to dry, then use the super high temp RTV

As mentioned, flatten the bolt areas back out, goop well, stick the cover on, SNUG the bolts, let the RTV cure, then snug bolts slightly more.

I have used gaskets on these, BAD PLAN :(

The valve covers are so thin (READ THIS AS CHEEZY) that they just don't accept gaskets well.

The entire set up was designed to use the RTV.

These covers are FLIMSY but work fine when installed as they were designed to be.

Good luck

Missy

[sfox]

Thanks for the advice. It is already sealed back up. I used brake kleen with the right stuff and I also purchased a new valve cover because the original was bad. I was just assuming that with the CDR that valve cover maintained no pressure and when it leaked last time it leaked immediately upon start up so allowing a few warm quarts to seep through there could point out any obvious problems.
Thanks again.

[Kennedy]

I've been liking the Ultra type sealers like ultra gray for jobs like this. I'd probably use black in the case of the 6.5 since it's more of a black color, but the Dmax being aluminum the ultra gray is best match.

Like mentioned above the key is to just start to snug down a bit then let it stand until cured.

[Yukon6.2]

Looking back to my join date.....
I did the repairs to my truck 10 yrs ago and there is a few spots that are beginning to weep.I used the black RTV silicon.
Thomas

[Robyn]

If you can get 10 years on it and only get a slight weeping, your gittenerdone.

I am told that the stuff Ford markets for this application is very good, and things stay dry.

I have never seen a 6.5 that did not have a little seepage after a good amount of time on the clock.


Missy

[Yukon6.2]

Yea i was pretty careful on all the sealing points i had apart.I'v owned a few green leakers over the years and always hated having to dive into them without trying to clean them.Most the time they breakdown away from the shop.