sealant when replacing gaskets?
Thread Starter
|
Senior User
Joined: Apr 2004
Posts: 143
Likes: 1
sealant when replacing gaskets?
Gentlemen,
I've got the oil pan and timing chain cover off my '79 351M for some work, and will soon be ready to put them back on. I have, of course, all new gaskets for all mating surfaces.
Question: what's the best thing to do for the new gaskets? Put them on bare? Coat one or both surfaces with RTV? Something else?
Thanks.
I've got the oil pan and timing chain cover off my '79 351M for some work, and will soon be ready to put them back on. I have, of course, all new gaskets for all mating surfaces.
Question: what's the best thing to do for the new gaskets? Put them on bare? Coat one or both surfaces with RTV? Something else?
Thanks.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
Many engine failures have been caused by RTV squeezing out of gasket areas and plugging the oil pump screen or fragments jamming the pump. Gaskets alone are intended to be the sealer between mating surfaces. Do not use RTV unless you don't have a gasket or there are deep pits in a mating surface that can't be repaired. When in those situations use only a very thin layer of RTV.
As far as the oil pan, -make sure the sealing surface of the pan is clean and flat. If it is a sheet metal pan make sure the areas around each bolt have not been deformed. You can use a socket and a ball pein hammer to make each fastener hole slightly concave. Use a gasket adhesive spray to adhere the gasket to the pan. When the adhesive has set coat the top surface of the gasket with a thin layer of grease to aid in removal next time. Torque the fasteners to the specs given in the manual. DO NOT crush the gasket by over torquing the fasteners.
As far as the oil pan, -make sure the sealing surface of the pan is clean and flat. If it is a sheet metal pan make sure the areas around each bolt have not been deformed. You can use a socket and a ball pein hammer to make each fastener hole slightly concave. Use a gasket adhesive spray to adhere the gasket to the pan. When the adhesive has set coat the top surface of the gasket with a thin layer of grease to aid in removal next time. Torque the fasteners to the specs given in the manual. DO NOT crush the gasket by over torquing the fasteners.
Post Fiend
Joined: Jun 2003
Posts: 5,643
Likes: 8
From: NE Texas
Eric is right about the RTV. Have you ever saw what petroleum products do to that stuff?
If you want to use a sealant other than what Eric suggested you can use Aviation Permatex but just make sure you have everything prepped first. Use it via the same process as Eric explained on the spray adhesive.
IMO - Spray is the best.
If you want to use a sealant other than what Eric suggested you can use Aviation Permatex but just make sure you have everything prepped first. Use it via the same process as Eric explained on the spray adhesive.
IMO - Spray is the best.
Thread Starter
|
Senior User
Joined: Apr 2004
Posts: 143
Likes: 1
Thanks. I found lots of RTV under the pan gasket. It looked like a hack re-install job.
Strangely, the timing chain and water pump gaskets came with a small tube of black RTV in the box. Maybe they just intended a dab of it for the joint at the corner of the pan where it crosses from the block to the timing cover.
Strangely, the timing chain and water pump gaskets came with a small tube of black RTV in the box. Maybe they just intended a dab of it for the joint at the corner of the pan where it crosses from the block to the timing cover.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
A dab in those locations is a correct application for the material. I usually use the Aviation Permatex also for those areas instead of RTV.
I have a can of 3M spray photo-mount adhesive that has been around for years that I use to adhere gaskets. I also use silicone dielectric grease instead of std grease on the mating surface of many gaskets. I did a couple of water pumps recently and used the spray and silicone grease. -No leaks!
Check your oil pump inlet filter screen while you are in there.
I have a can of 3M spray photo-mount adhesive that has been around for years that I use to adhere gaskets. I also use silicone dielectric grease instead of std grease on the mating surface of many gaskets. I did a couple of water pumps recently and used the spray and silicone grease. -No leaks!
Check your oil pump inlet filter screen while you are in there.
Post Fiend
Joined: Apr 2002
Posts: 7,157
Likes: 1
From: Central Kali
I have put many 302/351's together. I just use white grease. I hate scraping gaskets. I do use a dab of rtv on the corners of the intake manifold. For the valve covers I glue the rubber type gasket to the cover and grease the head side.
Thread Starter
|
Senior User
Joined: Apr 2004
Posts: 143
Likes: 1
Ya, I was wondering about the necessity of the gasket adhesive. Does it actually fulfill a sealing function, or just make mounting the gaskets easier? I'd love to get away without the adhesive....
Trending Topics
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
The adhesive is for holding the gasket in place during assy. If the gasket is not to complex you can use a light film of grease to help hold the gasket.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Logistics Pro
Joined: Apr 2004
Posts: 4,292
Likes: 5
From: NJ where fun comes to die
I found out the hard way not to use RTV a few years back. It caused a clog. I had to tear down the engine to clean it. I started to use permatex, but only the standard kind. Where do you get aviation permatex?
Post Fiend
Joined: Jun 2003
Posts: 5,643
Likes: 8
From: NE Texas
Originally Posted by trike1946
Where do you get aviation permatex?
It's called Permatex Aviation Form-a-Gasket Liquid - about 3 bucks for 4 oz. and it doesn't take much to do the trick
But it's worth it. I learned how good this stuff was when I had to replace the intake on an FE engine. That darn back gasket!
Thread Starter
|
Senior User
Joined: Apr 2004
Posts: 143
Likes: 1
Originally Posted by Torque1st
The adhesive is for holding the gasket in place during assy. If the gasket is not to complex you can use a light film of grease to help hold the gasket.