I recently changed the head gasket on my S70.
I have to pull the valve cover to change a cam seal to stop an oil leak.

When I changed the head gasket, I didn't change the head bolts. After doing some research, it seems that's recommended.

Is this something I should do now since I'm pulling the valve cover anyway, or is it not that big a deal?

 

bump

 

If you decided to do it, this would be the time.
Yes, you should use new head bolts each time, but if you were able to tighten each one without shearing any, you're good.
You don't have to pull the valve cover to replace the seals. Lever them out with a screw driver or seal puller. Another way is by using a sheet rock/sheet metal screw driven into the side of the seal and pulling it out with pliers & fulcrum.
Ed

 

The head bolts on these engines are torque- to- yield. What this means is that the bolts are tightened down- under perfect conditions, anyways, to their precise yield point. That means, the point at which they are just about to permanently stretch. When you tighten a bolt, it stretches a little bit. This is what provides the clamping force that you need. A head requires a LOT of clamping force, and the way to get the most is to tighten the head bolts to their yield point. Once you pass that point, clamping force goes WAY down on subsequent tightenings. Because we don't have perfect conditions to work with, you don't know if the original bolts were tightened beyond the yield point or not. If they were, they won't clamp as well. Contrary to popular belief, the danger of reusing TTY head bolts isn't that the bolts will break, unless they were WAAAY overtightened, but there is a real danger of head gasket failure due to insufficient clamping force from stretched bolts.

Now, since you've already changed the gasket, here's my recommendation- It's best if you do the whole thing over again- new head gasket and all, but if you don't want to, you can do this: Get a new set of head bolts. Then, remove one bolt at a time, following the tightening sequence- i.e. start with the bolt that is 1st in sequence, then #2, then 3, and so on. Remove the old bolt, then lube the new bolt with motor oil, and install it. Torque it to spec. move on the the next bolt, and do the same. Repeat until all bolts have been replaced. Do not, under any circumstances, remove more than one head bolt at a time or loosen any other head bolt until the one you've just changed is torqued completely, because you'll allow the head gasket to deform, and it will fail in short order.

 

Thanks for the info. I was able to replace that cam seal without removing the valve cover, but on reading Carrot's post, I think I'll be ordering up some head bolts and will end up pulling that valve cover after all to replace the head bolts