Need help w/removing 450SL valve covers

[rickjordan]

Got a friend with a '74 450SL and the valve cover gaskets are leaking a bit. Pulling the left valve cover off was easy, but the right side......
2 things get in the way of pulling the cover off completely, the vacuum line to the brake booster and 2 fuel lines. Removed the vacuum line which helped, but we still can't get the cover to clear the cam/rocker arms. Is there something I am missing, or do the 2 fuel lines do indeed need to be disconnected. If that is the case, how much gas will come out? Though I can't imagine much since the system will be de-energized.

Thanks.

[rowdie]

Yes they must be removed and very little gas will come out. A rag will work. Mark them so you don't get them crossed.
For future reference left and right are identified from the rear not the front.

[DieselPaul]

IIRC the feed and the return are different sizes, as long as you pay attention reassembly isn't a big deal.

[rowdie]

My '72 and '73 have the same size on both lines.

[rickjordan]

Thanks for the replies. What prompted us to try and remove the covers, other than the leaking valve cover gaskets, is to attempt a valve adjustment. Per the manual this is supposed to be done every 10K. My friend doesn't know if and when the previous owner had the valves checked. I have adjusted valves before on a W123 diesel. Per the manual it says to use a "special tool". Is that absolutely needed? To me it looked as if a simple 17mm crows foot and an extension would have the same effect. Admittedly, we tried on the passenger side to loosen the adjustment nut, but she would not budge. Using a feeler gauge, we checked the clearance and the valves were tight. In other words, we couldn't get the gauge under the lobe. So we attempted as I said, to loosen them, but no go. I certainly didn't want to put too much force on it.

I guess with in all of this I have 3 questions. Can a crows foot subsitute for the "special tool"? How much force should it take to loosen the adjustment nut? Finally, is too tight, better than too loose for these valves. This is just incase we can't loosen the adjustment nut.

As I said, I have adjusted valves on 123s before, but those were straight 5 cylinders with clearance for wrenches.

Thanks again.

[rowdie]

I broke a cheap crows foot trying it. Good quality 17mm is needed but it will work. Some turn with medium force but most require quite a bit. The advantage of the tool is the build up on the foot that rest against the head and keeps the jaws in contact with faces of the adjuster. It is also bent so that down force keeps it in contact with the head.

[rickjordan]

I have Craftsman tools and have never broken one, so I think I am good there. So, should I go ahead and loosen them so that I can slip the feeler gauge under the lobe, or leave them as they are? As I mentioned, we could not get the gauge under the lobe, to then feel a slight drag indicating the correct lash.
Thanks again

[RadioTek]

This is the special wrech that I bought for this job. Since it's a 1/2" drive Snap-On tool, it's strong enough to use a 18" breaker bar to provide enough leverage to move the adjusters. I had to "pop" a couple to break them loose, but no real problems.

New Snap-on17mm 1/2" Drive Valve Adjustment Tool S6014 | eBay

A lot less than the Hazet ones in the other sites.

Scott

[rowdie]

Yes. Go ahead and loosen them as needed.

[rowdie]

Hazet tool

[rickjordan]

So, its ok to put some real muscle, ie; use a breaker bar, to get these loose to then tighten to the correct spec?
Why are these so tight? Do these adjustments tighten up on their own, hence the requirement to adjust every 10K.