Have an 87' Buick Grand National that started leaking at the rear main seal. The factory seal is a rope seal. It is a very small leak. Would AT-205 help with this? Or would other products work made of petroleum distillates. I am thinking no but figured I would ask the experts.
Will ATP AT-205 help a rope rear main seal?
- Thread starter GroundLoop
- Start date
I do. Valvoline dino high mileage Max Life 10w-30. Also add ZDDP zinc additive because cam is a flat tappet.
no
nothing you can put in the oil works on rope seals
the only fix is modding it to use 'modern' lip seals as rope seals are no longer made quite the same way as they used to be so they all leak
the big block Buick guys go with a Ford seal of some type if I remember correctly
you can slow it down with thicker oil but it just gets worse and worse over time
nothing you can put in the oil works on rope seals
the only fix is modding it to use 'modern' lip seals as rope seals are no longer made quite the same way as they used to be so they all leak
the big block Buick guys go with a Ford seal of some type if I remember correctly
you can slow it down with thicker oil but it just gets worse and worse over time
- Joined
- Sep 25, 2020
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- 186
You sure that engine has a rope seal? I'd think it would share the same seal at a sbc. So 2 piece lip
The OEM rope seal in my 87 GN leaked as well, a common problem. I was lucky in that a GN guy in my area replaced it with another OEM rope seal. Sold it at 99,000 miles and it wasn’t leaking. IIRC Dennis Kirban might have a neoprene seal available now.
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I have a very similar car, 89' Pontiac Turbo Trans Am that has the same engine. I replaced the rope seal on that with the recommended Felrpro neoprene seal. No leaks. I can do it. Was just looking for a quick fix. Too many projects. Oh well, add it to the list.
Thanks for the clarification.
Thanks for the clarification.
