# Viton Seal leaked terrible. Installing Graph Tight Seal



## timmyg (Jan 2, 2012)

I have got my 455 engine ready to come out in the morning. I will then proceed with removing the pan, crankshaft, etc. When I got my car, the Rear Main seal leaked terrible. It had the rope style seal. I removed the engine and replaced with the Viton seal which I had a tech from BOP walk me through the process of installation. The Viton seal leaked worse than a sieve. Tomorrow I will start the process again of replacing the Rear Main Seal, thus removing the Viton Seal. I am going to replace with the new Graph Tight Seal from Best Gasket Co. I was wondering does anyone have any tips or experience with the Graph Tight Seal that I should know about when installing this Rear Main Seal. I so want this seal to do the trick and not leak. I do not want to go through this again. Is there any thing I should be looking for on the Crankshaft in the area where the Rear Main Seal goes that may be causing the issue, or should I just assume that the previous seals simply did not work. I was wondering if there could possibly be a thrusting issue with the Crank that could be causing the issue. Does that sound possible?? The engine is a 1970 455 HO. Crank has 10 under Main Bearings installed. As always, any advise is appreciated.


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## geeteeohguy (Feb 2, 2008)

Timmy, get on the pyforumsonline and pull this subject up. There are many posts and all of the information you need is discussed to the Nth degree. You are smart to do the homework and minimize risk. Graph-tite seals are the ticket for big-journal blocks, but they install differently than the old style rope seal. Talk to the guys who use them. Good luck.


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## timmyg (Jan 2, 2012)

Thanks Geeteeohguy for the advice. I can always count on you for answers and advice to my questions. I really appreciate it.


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## kilkm68 (May 5, 2011)

I also have a 1970 455 block that we installed a Vinton seal I got from Ames. A friend helping me install the seal was afraid it would leak like crazy, but I've had no leaks after 3 years. I found a little oil on the inspection cover last time I was under the car but just a tiny amount and none on the garage floor. I've heard of others having trouble with them but I'm very pleased with it. The old rope seal that was in the engine leaked badly.


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## timmyg (Jan 2, 2012)

*Graph Tite Seal installed*

As I had wrote earlier, I was removing the Viton Seal that was leaking terribly in my 455 and installing the new Graph Tite Seal. I finished up with installing the new Graph Tite Seal and re installed the engine today. After about five minutes or so of running time with nothing leaking, it began to drip. I installed the new seal with the instructions that were included to the letter. Removed Crankshaft totally from the engine as that is the only way to get the seal into the top part of the block correctly. I am disappointed to say the least. I don't know what else to do. I read on the forum that some folks engines are leak free and other folks are fighting rear main leaks like I am. I hate to even go here, but has anyone ever tried one of the products that you can supposedly add to the oil that can help with rear main seal leaks. If so how did it perform and if it performed well, what was the name of the product. As of now I am at a loss. I do not want to remove engine yet again, however if the oil starts flying underneath the car again and on the rear bumper, I certainly will have to do something. Talk about disappointing!!


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## kilkm68 (May 5, 2011)

Do you have a good PVC system on the motor? I bought my Vinton seal from Butler Performance and talked at length with Jim Butler about the rear main seal problem. He told me the main problem with rear main seal leaks is caused be crankcase overpressure. He said they had blown oil all over the wall on engines on the dyno in the shop. He said excessive pressure in the crankcase blows oil right past the rear seal. He advised me to install one of the Vinton seals with an oil separating breather cap plumbed up to the air filter assembly. He said this would create a negative pressure that would relieve the excessive pressure in the crankcase. I did ad he suggested and after 2 years I have no leaks. Engine leaked badly before with the rope seal and no PVC.


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## geeteeohguy (Feb 2, 2008)

The stop-leak products for oil leaks do NOT work on rope type or packing type seals. Only rubber seals. So, no, you won't be able to perform a miracle fix. The reason Graph-tite seals fail is usually due to incorrect installation. Too tight an installation will result in the crankshaft 'grabbing' the seal on start up and spinning the seal in the groove at high speed, which burns it into a 'cat turd' appearing object that leaks. Big journal blocks like yours can have trueness issues at the real main.The secret is in the install. Cliff Ruggles, among others, has a lot of experience with this seal and is on the forum I previously mentioned. If you want to fix the oil leak, the engine has to come out again. The crank journal and rear main need to be checked for issues. Sorry about your frustration.


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## timmyg (Jan 2, 2012)

I have the PVC system on the Tri Power that comes from the intake between the middle and back carburetor and goes into the valley pan to the right of the front carburetor. Also have breather type caps on the valve covers. Next step is to do what I thought about doing last time before putting in the Graph Tite Seal which was said to be the "Savior" of Rear Seals. That is, take the crank out again and take it and the rear main cap to machinist to be checked.


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