I just used this in my roommates 97 Grand Cherokee 4.0L . She bought it recently for 1k with alot of miles , anyways it has been leaving a nice stain on the driveway which was quicky diagnosed as a rear main seal. Not having the time to replace the rear main seal for her , I suggest to try this stuff . I was really skeptical it would work ,but too my surprise it has lost a drop of oil in a week. Thoughts on this? I suspect that when this is drained out that the seal swelling will stop.
Bar's rear main seal repair
- Thread starter Thax
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Maybe using a stout high mileage oil would help .
It works but you are right that if not used again, it will happen again at the next OCI. Use a high Mileage oil at the next OCI, something like Maxlife ot PYB HM... I believe those engines like 10W30.I would try PYB HM 10W30.
Current fill is QS defy 10w-30 with a Mopar filter. Engine is an obvious rebuild with unknown miileage, however the internals are spotless. No idea as to the OCI or oil used by the PO. I just find it interesting that it stopped the leak completely and so fast. I wonder if it is due to the 4.0L two piece rear main seal design.
Defy is a very good oil and I have used it in a few collector cars.
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I have to say this is a good product. Slowed a leak in friends Civic significantly in the last two weeks. I know it is a bandaid but if I had a beater I would consider using this. Also, we tried 3 OCI's with various HM oils and it helped very little. The Maxlife helped the most but I dont know if that is just because it was the oil used on the 3rd OCI. Bars Leaks Rear MS appears to do what it says.
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How thick is it?
According to the TDS from Bar's it is a 40 weight. Viscosity at 100C is 14.9 , VI of 92. Flashpoint of 453F and pour point of -33. This stuff isnt just another overly thick sealer, per the MSDS it is heavy in Ester which would account for the leak stoppage. For $7 bucks a bottle and completely stopping a bad leak in a $1k Jeep ,im impressed.
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