can't get em' to seal... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**'70_402** · 07-09-2004, 02:13 PM

I have a set of valve covers off of a 95 chevy 454 (the ones with the o-ring gasket) and i can't get them to seal right....what is the deal??? anyone else using these have this problem????

Tx Firefighter · 07-09-2004, 11:48 PM

Are you using them on your 402?

If using them on an earlier engine, there is a slight modification you need to do to the lip of them to get them to seal. The GM Power manual has all of the details on what to do.

franko72 · 07-10-2004, 09:37 AM

being patient is the first part. check your valve covers for dimpling or warping at the holes from over tightening.I would have both mating surfaces clean and dry.I use permatex spray gasket adhesive and felpro rubber gaskets to glue to the valve cover surface.place gasket to valve cover and let it dry completely.place rocker cover on the heads slowly making sure they are lined up as close as you can be before making contact.dont over tighten. I know some are reading this thinking (no kidding man!)but I have found that most of my problems were that I hurried and didnt take my time to do a simple task. Good Luck

Tx Firefighter · 07-10-2004, 06:05 PM

They should be the aluminum ones, so they won't be dimpled or bent.

I went ahead and took a picture of the article in the Chevrolet Power book. These valve covers must be modified to seal properly on your engine. It's not sloppy install procedure that's the problem.

franko72 · 07-10-2004, 07:08 PM

my 402 does not have aluminum rocker covers , they are a thin steel type.

browndawg71 · 07-10-2004, 07:11 PM

i run these on my 468 and have had the same problem. i took the o-ring out and ground the tits on the under side of the vavle cover off and put on regular cork gaskets (thick) on it and it stopped it.

Tx Firefighter · 07-10-2004, 07:11 PM

Franko....Yes, but his are off a 95 model 454. Those are known ans GEN-V engines.

If you look closely at the picture in my picture above, there is a lip that needs to be ground or machined off. Those late model aluminum covers use an o-ring instead of a gasket.

franko72 · 07-10-2004, 10:19 PM

Got it 95 duh!

**'70_402** · 07-12-2004, 09:30 AM

What is the power book and where can i get one of them?? Thanks firefighter...that is kinof what i thought but wasn't sure about the lip on them....

Tx Firefighter · 07-12-2004, 05:12 PM

I got mine at my local GM dealer. Tell them you want the Chevrolet Power Manual. It cost about 19 bucks. Worth it too.

07-09-2004, 02:13 PM	#1
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	can't get em' to seal... I have a set of valve covers off of a 95 chevy 454 (the ones with the o-ring gasket) and i can't get them to seal right....what is the deal??? anyone else using these have this problem???? __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

07-09-2004, 11:48 PM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Are you using them on your 402? If using them on an earlier engine, there is a slight modification you need to do to the lip of them to get them to seal. The GM Power manual has all of the details on what to do. __________________ I'm on the Instagram- @Gearhead_Kevin

07-10-2004, 09:37 AM	#3
franko72 Franko72 Join Date: May 2004 Location: Cincinnati,Ohio Posts: 471	being patient is the first part. check your valve covers for dimpling or warping at the holes from over tightening.I would have both mating surfaces clean and dry.I use permatex spray gasket adhesive and felpro rubber gaskets to glue to the valve cover surface.place gasket to valve cover and let it dry completely.place rocker cover on the heads slowly making sure they are lined up as close as you can be before making contact.dont over tighten. I know some are reading this thinking (no kidding man!)but I have found that most of my problems were that I hurried and didnt take my time to do a simple task. Good Luck __________________ 1972 C20 cheyenne Super 402 BB/400 turbo LWB A/C Tilt, Cruise Control, Saddle tanks, Tach My Home Page Better to burn out than it is to rust

07-10-2004, 06:05 PM	#4
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	They should be the aluminum ones, so they won't be dimpled or bent. I went ahead and took a picture of the article in the Chevrolet Power book. These valve covers must be modified to seal properly on your engine. It's not sloppy install procedure that's the problem. Attached Images __________________ I'm on the Instagram- @Gearhead_Kevin

07-10-2004, 07:08 PM	#5
franko72 Franko72 Join Date: May 2004 Location: Cincinnati,Ohio Posts: 471	my 402 does not have aluminum rocker covers , they are a thin steel type. __________________ 1972 C20 cheyenne Super 402 BB/400 turbo LWB A/C Tilt, Cruise Control, Saddle tanks, Tach My Home Page Better to burn out than it is to rust

07-10-2004, 07:11 PM	#6
browndawg71 Registered User Join Date: Jun 2004 Location: paris, texas Posts: 235	i run these on my 468 and have had the same problem. i took the o-ring out and ground the tits on the under side of the vavle cover off and put on regular cork gaskets (thick) on it and it stopped it.

07-10-2004, 10:19 PM	#8
franko72 Franko72 Join Date: May 2004 Location: Cincinnati,Ohio Posts: 471	Got it 95 duh! __________________ 1972 C20 cheyenne Super 402 BB/400 turbo LWB A/C Tilt, Cruise Control, Saddle tanks, Tach My Home Page Better to burn out than it is to rust

07-12-2004, 09:30 AM	#9
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	What is the power book and where can i get one of them?? Thanks firefighter...that is kinof what i thought but wasn't sure about the lip on them.... __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

07-12-2004, 05:12 PM	#10
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	I got mine at my local GM dealer. Tell them you want the Chevrolet Power Manual. It cost about 19 bucks. Worth it too. __________________ I'm on the Instagram- @Gearhead_Kevin



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