valve covers wont stay tight

Ive done changed my valve covers twice now, replaced gaskets, used just about every kind of sealant there is and they leak oil constantly. I have a 1970 GMC truck, 350 , 286 comp. cam .

Reply to
gmc70
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Reply to
Shep

Do you have spreader bars under the bolt? Are you tightening the bolts to the recommended spec? Make sure that the bolts do not bottom out or have bad threads. Make sure that the gasket edge of the cover is flat and that there is no damage to the head. If all is good and it starts to leak try to re-torque to spec.

Reply to
Scott Buchanan

In those years, GM had a pretty sad valve cover gasket setup. The covers are tin, and if they aren't straight you can have problems, if someone has overtightened the bolts and deformed the holes in the valve cover you can have problems. There was a "spreader" kit that GM had for those older valve covers. You would get studs that screwed into the cyl heads, and large spreader bars that went on top of the valve cover at each hole. They also had a special set of valve cover gaskets that you used with the kit. The spreader bars helped to spread the clamping load over more of the valve cover area.

You could also use RTV, but you have to make sure the mating surfaces are perfectly clean and dry (no oil).

Ian

Reply to
shiden_kai

What Ian says in his post about the early small block valve covers is right on, I've always opted for an aluminum set. They are much less prone to leaking.

Brian

Reply to
el Diablo

Reply to
none of your business

That's a good point, the rear of the intake gasket can also fool you if you don't look close enough.

Brian

Reply to
el Diablo

If it has a PVC system are you sure it's working and not pressurizing the crankcase? If so the oil gets pushed out through the weakest gaskets.

Ted

Reply to
Ted Mittelstaedt

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