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Valve cover gasket - head surface sealing

2K views 29 replies 13 participants last post by  79AMCJeepCJ5 
#1 ·
Have had a leak coming from the back of the motor from when I bought the jeep. Got a felpro gasket and pulled the cover. I was cleaning the mounting surface side of the head and noticed these marks. I'm assuming this is causing the leak. Suggestions on sealing this. They are really shallow gouges. RTV blue?
 

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#2 ·
I'm not seeing anything catastrophic. A Felpro cork gasket, and "the right stuff" sealant. Read and follow the instruction. Stuff works amazing.
 
#3 ·
I just replaced my valve cover twice 2 weeks ago. first when I rebuilt it on the stand I used a Felpro gasket and enough rtv to hold it in place. The problem, as I found later, was the poor fitment of the gasket at the front and back, at least on my Clifford cast aluminum cover. So I figured I'd try that "Right Stuff". Two problems with using that stuff is you need way more than the 1/8-1/4" bead they recommend because you need an equal spacing above the head surface or your bolts will bottom out before it's sealed. I had three leaks with it. The second issue is that stuff is like super glue and you'll play heII getting it back off. Took me over an hour and enough prying force that I thought might crack the cast cover.
So after that came off, and another cleaning of both surfaces, I used a combo of another Felpro gasket and a small bead of rtv above and below. However, the gasket ends had to be trimmed (with an angle grinder and 36 grit disk) so it fit within the lip of my cover with no overhang. You can see here how the holes don't line up yet so it needs a bit more grinding.
I have no leaks now.
 

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#5 ·
Thanks for the reply's. The gasket theme has been beaten to death and various methods are successful but I never understood using both RTV and a gasket. In my mind the gasket IS the gasket. IMHO why add more seams in a seal by using both unless you have imperfections in the mounting surface. In my case I'm wondering if a really thin coat that only fills the small gaps/gouges in the photo and only in that area. I was thinking of using a straight edge like a putty knife and running the RTV over the gouges leaving only RTV in the reliefs on the top of the head.
 
#6 ·
I tried every combo of cork/composite/RTV gaskets imaginable, with no joy.

My first attempt with The Right Stuff, only, worked like a charm.

The key to TRS is a nice healthy continuous bead, first. Then it's imperative to not mash the TRS too thin when placing the valve cover on it. I found it was helpful to let the TRS set up for a minute or two before installing the cover. Lastly, just torque the VC bolts only a !/4-turn past hand tight, and let it sit over night.

This is the procedure that finally created a leak-free valve cover on my 258.

Matt
 
#7 ·
I tried every combo of cork/composite/RTV gaskets imaginable, with no joy.
I tried several combinations as well, and none of them were leak-free more than a couple of months. I am convinced that part of the problem is the light torque setting specified by AMC that makes it easy for the bolts to loosen.

My next attempt will be to use only The Right Stuff along with some thread locking sealant on the bolts.
 
#8 ·
bigred85 said:
In my case I'm wondering if a really thin coat that only fills the small gaps/gouges in the photo and only in that area. I was thinking of using a straight edge like a putty knife and running the RTV over the gouges leaving only RTV in the reliefs on the top of the head.
This, a Felpro gasket, thread locker, and a torque wrench worked for me. Felpro had two options for my engine, I used the pricier one.
 
#12 ·
Well I will say this, if you set the cover on the head without anything, and put your bolts in till they bottom out, you'll see what kind of space you need to make up with sealant or gasket, because the cover will still be loose. Keep in mind they used different head castings thru the years and some have tabs (for lack of better word) along the side that limit the spacing between once the cover contacts it.
I'm also wondering if those who use that Right Stuff have ever tried to separate a cover where that stuff was used. You don't just simply pry it off!
 
#14 ·
Don't use the cork gasket use the 40 dollar one from the local parts store. I can't remember what it's called but I don't have the greatest track record when it comes to gasket and seals and I had no leaks using this gasket- I even removed the valve cover once-didn't reseal it with sealer and still no leaks.
 
#19 ·
Is that the PermaDry Plus gasket? I didn't realize the 86 Jeeps had a different cover / head. Looks like they only offer it for the 1986 258's(50522T) and the bigger v8's. No listing for an 80- 304 or any six's 1985 or older. Matt, what was your engine out of?
 
#21 ·
Honestly, I don't recall if mine are the regular PermaDry, or the Plus.

My 360 is an '81 from a J10. The factory steel valve covers have notches around the perimeter. The FelPro gaskets have tabs that correspond to those notches, perfectly. So, you can pop the gasket directly onto the cover, and it stays in place as you set the cover.

Matt
 
#26 ·
Renegade82 said:
No not the picture. I meant that neither AutoZone or Felpro's site list them as available for the 6cyl for any years other than 1986, which is odd. If they're not different I don't know why it wouldn't fit other years.
Yeah. I know the fel pro site only lists two options for my '78. Both cork. One 5/32 the other 7/32 thick
 
#28 ·
So I wonder if this blue FelPro PermaDry gasket with the spacer bushings they offer for the 86 would fit other years? Does anyone know of any difference in the castings for these last Jeeps? And when AMC came out with the wrangler model they used the remaining stock of Jeep 258's for the optional upgrade. If I remember right they didn't change to the 4.0 head till a couple years later so theoretically the first couple years of the wrangler model should fit as well. I didn't look on Felpro's site for those.
 
#29 ·
Update:
I bought one of the FelPro 50522T Blue PermaDry gaskets at NAPA for an 86 Jeep. It don't fit, wrong shape. It looks to maybe fit a 4.0 head (which wasn't available in 86, not till 88 or 89 I believe). It has 5 bolt holes along the straight (pass.) side. Looks like FelPro's website is wrong!
 
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