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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: vince311 on October 14, 2008, 11:28:56 pm

Title: valve cover installation question
Post by: vince311 on October 14, 2008, 11:28:56 pm
Rookie questions: I'm currently replacing valve cover gaskets on my 350...as they've been leaking. I've heard a couple different processes for replacing these...wondering if anyone can confirm?

My plan is to clean the top of the head, place the new gasket on top of the head, then run a bead of RTV all the way around, then mount the valve cover, tighten cover bolts (in a cross pattern).

This sound right?
Title: Re: valve cover installation question
Post by: Captkaos on October 14, 2008, 11:41:10 pm
Cork or rubber?
I generally put a thin coat of silicone on the valve cover to secure the cork on, nothing on the block.
I don't do anything for rubber gaskets, but install them.
DO NOT over tighten them or you are asking for a leak.
Title: Re: valve cover installation question
Post by: vince311 on October 15, 2008, 10:36:18 am
Cork or rubber?
I generally put a thin coat of silicone on the valve cover to secure the cork on, nothing on the block.
I don't do anything for rubber gaskets, but install them.
DO NOT over tighten them or you are asking for a leak.

perfect! thanks chris. do you use a torque wrench?....25 ft/lbs enough?
Title: Re: valve cover installation question
Post by: eventhorizon66 on October 15, 2008, 10:56:46 am
25 ft/lbs is too much.  Just snug and nothing more.
Title: Re: valve cover installation question
Post by: 78 Chevyrado on October 15, 2008, 11:27:17 am
25 ft/lbs is too much.  Just snug and nothing more.

I agree.  Since you just snug them down remember to make sure the sealing flange in the vale cover is flat, as waves/dents=leaks.
Title: Re: valve cover installation question
Post by: Captkaos on October 15, 2008, 05:43:40 pm
more like 25 in/lbs.
Title: Re: valve cover installation question
Post by: VileZambonie on October 15, 2008, 06:17:50 pm
45 in. lb on the valve cover bolts.

The gasket should be installed on the valve cover first. If you find it necessary to glue the gasket to the cover you can use an adhesive sealant or weatherstripping adhesive. Do not make an RTV sandwich.

Torque the covers evenly in a cross pattern for perimeter covers and use load spreaders.

For center bolt valve covers 65 in. lb
Title: Re: valve cover installation question
Post by: choptop on October 15, 2008, 09:27:06 pm
If you are running the stamped steel valve covers, I highly recommend getting a set of spreader bars ( dont know if thats the right terminology) to help clamp the load more evenly.
Title: Re: valve cover installation question
Post by: vince311 on October 15, 2008, 09:45:27 pm
45 in. lb on the valve cover bolts.

The gasket should be installed on the valve cover first. If you find it necessary to glue the gasket to the cover you can use an adhesive sealant or weatherstripping adhesive. Do not make an RTV sandwich.

Torque the covers evenly in a cross pattern for perimeter covers and use load spreaders.

For center bolt valve covers 65 in. lb

I have four bolts on each valve cover, so the load spreaders sounds like a good way to go.
Title: Re: valve cover installation question
Post by: choptop on October 15, 2008, 09:50:17 pm
Vile already said that huh?? I missed that part ::)
Title: Re: valve cover installation question
Post by: GoatBeard on October 16, 2008, 09:24:11 am
If you are using the hand-tightening-type wing-nuts be sure and check them occasionally -- they will loosen up with time.


Recently changed mine out and the parts store talked me into getting the expensive "no silicone" rubber gaskets.  I had cleaned the old covers & painted them up all purdy.  I put them on, tightened everything back up (AC/etc) and went from 1 gasket leaking to both gaskets leaking. 

Sooooooooooo............

I took everything back off (A/C etc), took the rubber ones back to the parts store & got the more familiar cork ones.  Went ahead and got a set of chrome valve covers (didn't know if the old ones may have been warped and FOR SURE didn't want to take those things off a third time as my back hurt so bad from bending over the engine compartment from the first install I about cried when I saw them leaking).  Got everything back together and there was no leak. 

I don't know if it was the old valve covers that were warped or if it was the expensive rubber "no silicone" gasket that was bad, but I'll not be buying the rubber ones again.  Other people may have had good luck with the rubber "no silicone" gaskets, but doing a job that requires to be on a ladder bent over an engine compartment should work the first time.   ;)