Does high mileage oil cause more leaks? Any cons to putting at-205 in oil?
rear main seal thoughts. (1 Viewer)
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2001LC
SILVER Star
I've and 00 w/~360K miles, no oil leaks.
I'm not big on adding as a PM. But should not hurt. Manufacture of AT-205 is a seal maker. They explained to me, AT-205 is a plasticizer, using adds back what time and certain condition have cause to deplete. But use only amount specified (~1.33 oz per qt of oil). I've used on many rubber products (auto, shop and household) for about 3-4 years now. So far, I've not seen any adverse effects.
I'm considering adding to rear differentials. Why there! Because if we get axle seal leak, it can damage axle bearings. I've run into two for sure rear axle seal leaks. Also 2 possible weeps.
One thing that happens is cheapo oil & gear lubes used, and poor flushing intervals. Gunk builds up on seals (seems more so than on o-rings) like axle, cam and crank seals. Gunk will draw out plasticize and dry seal IMHO. We then come along, and use synthetic oils. Which cleans away gunk and we then see leaks/weeps. We get very good results with AT-205, in these cases. With age related plasticize depletion ( dry seals shrunken seals), we get good results also. Damaged seals, well, they need replacing. If damage from use of HM oil, IMO it depends on how long ago and how damaged. But that's still a question I have if at all effective with those.
I'm not big on adding as a PM. But should not hurt. Manufacture of AT-205 is a seal maker. They explained to me, AT-205 is a plasticizer, using adds back what time and certain condition have cause to deplete. But use only amount specified (~1.33 oz per qt of oil). I've used on many rubber products (auto, shop and household) for about 3-4 years now. So far, I've not seen any adverse effects.
I'm considering adding to rear differentials. Why there! Because if we get axle seal leak, it can damage axle bearings. I've run into two for sure rear axle seal leaks. Also 2 possible weeps.
One thing that happens is cheapo oil & gear lubes used, and poor flushing intervals. Gunk builds up on seals (seems more so than on o-rings) like axle, cam and crank seals. Gunk will draw out plasticize and dry seal IMHO. We then come along, and use synthetic oils. Which cleans away gunk and we then see leaks/weeps. We get very good results with AT-205, in these cases. With age related plasticize depletion ( dry seals shrunken seals), we get good results also. Damaged seals, well, they need replacing. If damage from use of HM oil, IMO it depends on how long ago and how damaged. But that's still a question I have if at all effective with those.
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Three of my vehicles have a type of aluminum timing cover, seal, and upper oil pan that reminds me of this problem. The tricky part is to install the cover with RTV on the lower part that butts up against the upper oil pan without removing the upper oil pan. If you don't have the upper oil pan removed, the RTV just scrapes off and goes down into the oil pan. It does not end well.
Like we see in the picture, there are guide pins that force the cover to be mounted straight on so the bolts will align. There is an insider trick for that engine to remove the guide pins, and to not install the seal until the end. That allows the cover to be tilted at a slight angle for installation without the bottom (where the RTV is located) pressing up against the upper oil pan until the end when the lower bolts are partially and the cover is pulled into the upper oil pan. Then once the cover is in place and the bolts are started, the guide pins can be inserted from the outside. Note these are aluminum blocks where the guide pins can be easily removed and reinstalled if they get in the way. It may not be possible with an iron block. And then there is the issue of making sure the o-ring doesn't get pinched in the process.
If I'm faced with this situation in the future, I might pull the engine and do an all-out reseal.
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2001LC
SILVER Star
They list LSD as a use, they also build diff.. I first used in a 100 series rear diff, about two years ago. That one has about 15K miles on it now, no issues reported.
Re-Seal
PART NUMBER : AT-205Features & Benefits
AT-205 Re-Seal is a fast, effective and safe stop-leak for all rubber seals and gaskets. The exclusive formulation restores worn or dried out seals and is not harmful to internal bearings and components.Stops leaks in:
Engine - Gasoline and Diesel
Transmission - Automatic and Manual
Power Steering - Rack & Pinion and Steering Box
Differential - Conventional, Limited Slip and Locker
Hydraulic Systems - Plows, Lifts, Jacks and Industrial Equipment
(Do not use in brakes)
- Professional strength, fast acting resealer
- Compatible with conventional and synthetic oils, ATF, gear oil, power steering fluids and hydraulic oil
- Does not contain petroleum distillates, will not over-swell or breakdown seals
Disclosure. I do not on stock in ATP....LOL May be I should!
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2001LC
SILVER Star
To very clearly answer the first part of your question: YES HM oil causes leaks.
It was first stated to me in mud, back some years ago. "It's like running your engine on "crack"".
I called Mobil 1 support, on the issues of HM oil. They said:
If HM oil used for two oil changes, it must then always be use. It is a petroleum based seal modifier.
HM oil should come with a warning. Addictive, long term use kills!
Many including myself want the best for their engine. We see High Mileage on the jug of oil and think; Yeah, that's my rig! HM.
I once installed it. Fortunately mud saved me from the addition. I had in less than 500 miles.
I just ended up removing the plate, cleaning everything 100% and fpig'ing everything back including the bottom of the metal plate that sits on the upper oil pan.
The o ring was plastic at this point. I'm pissed I missed the front one when I did the timing belt and cam and crank seals last month, oh well.
I also used synthetic oil (not high mileage) twice when I first got her. The leak started around that time. This was 4 or 5 years ago at 135k. Currently at 183k
Question is, considering the seals are new, can I go back to synthetic?
The o ring was plastic at this point. I'm pissed I missed the front one when I did the timing belt and cam and crank seals last month, oh well.
I also used synthetic oil (not high mileage) twice when I first got her. The leak started around that time. This was 4 or 5 years ago at 135k. Currently at 183k
Question is, considering the seals are new, can I go back to synthetic?
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2001LC
SILVER Star
Synthetic oil does not hurt seals. Some find leaks after its use, Why! IMHO it cleans seals and reveals issue already there.
They list LSD as a use, they also build diff.. I first used in a 100 series rear diff, about two years ago. That one has about 15K miles on it now, no issues reported.
Re-Seal
PART NUMBER : AT-205
Features & Benefits
AT-205 Re-Seal is a fast, effective and safe stop-leak for all rubber seals and gaskets. The exclusive formulation restores worn or dried out seals and is not harmful to internal bearings and components.
Stops leaks in:
Engine - Gasoline and Diesel
Transmission - Automatic and Manual
Power Steering - Rack & Pinion and Steering Box
Differential - Conventional, Limited Slip and Locker
Hydraulic Systems - Plows, Lifts, Jacks and Industrial Equipment
(Do not use in brakes)
- Professional strength, fast acting resealer
- Compatible with conventional and synthetic oils, ATF, gear oil, power steering fluids and hydraulic oil
- Does not contain petroleum distillates, will not over-swell or breakdown seals
Disclosure. I do not on stock in ATP....LOL May be I should!
I tried the AT-205 on 2 of my cars recently:
A. I used the full bottle in the LX Crankcase (filled w/ M1 5W-30) to cure a RMS leak and approx 1 ounce in the PS fluid (M1 ATF) to stave off a small PS leak at the rack. Results: Turns out that it was not the RMS but the oil pump o-ring, and the AT-205 was not effective on that. More troubling (for me), the next day the PS fluid reservoir was filled with froth and the pump was groaning and assist was intermittent. Flushed all of the froth out and refilled w/ M1 ATF and the groaning went away and assist is back.
B. I used it in my E36 engine'd E30's PS reservoir to stave of a small rack leak. It also frothed and even worse, the pump groaned to the point of complete loss of assist and me shopping for a NLA pump. Just because, I drained it out as well, and replaced with M1 ATF. Fingers crossed but that did the trick. Assist is back and the pump is back to silent.
Cliffs: In both my applications, the PS reservoirs were previously filled with M1 ATF and I then added a prescribed amount of AT-205 to stop small leaks. In both instances, it caused excessive frothing of the fluid causing loss of assist and loud PS pumps. Countermeasure: drained and refilled with 100% M1 ATF. Result: Operation back to normal, no improvements on leaks. It was also not effective for me to stop a oil pump oring from leaking.
I'm not sold on the AT-205.
Apparently there's two identical ones. One in the front and one in the back.
I only did the one in the back, as that's where I was working.
Thanks for the quick reply...
So the rear main seal, FIPG, and that O-ring was the only thing you replaced? and did this solve leaking problem?
Yes, rear main seal, o ring, and Toyota fpig.
500 miles, zero leaks with synthetic oil.
I finally reinstalled my skid plates after 2 years
Bumping this thread again, this had some great info.
I am replacing my engine with a new/used one that has 220k on it. Does everyone recommend doing the o rings on the front and back as well as the rear main seal while I have the engine out? No time line to get it reinstalled so I can take my time. Or is this job too much of a PITA if they aren’t leaking on the new engine?
I am replacing my engine with a new/used one that has 220k on it. Does everyone recommend doing the o rings on the front and back as well as the rear main seal while I have the engine out? No time line to get it reinstalled so I can take my time. Or is this job too much of a PITA if they aren’t leaking on the new engine?
awesomeissquid
SILVER Star
Do everything you can before installing the new engine. It is easier and you dont have to worry about it for another 200k miles.
I suspect the RMS in my 06 LX is leaking, and I was also told that by a mechanic.
My oil consumption is nil, and the oil underneath isn't much at all.
Is this (replacing RMS, O-ring etc) something you guys put off until oil consumption or oil leaking oil is more notable?
Is there risk of catastophic failure of anything with a "watch and monitor" plan?
I've checked and tightened VCG bolts and don't feel they are contributing.
My oil consumption is nil, and the oil underneath isn't much at all.
Is this (replacing RMS, O-ring etc) something you guys put off until oil consumption or oil leaking oil is more notable?
Is there risk of catastophic failure of anything with a "watch and monitor" plan?
I've checked and tightened VCG bolts and don't feel they are contributing.
Mine is at Toyota the moment having the Rear Main Seal replaced.
I'm a little put out in that the truck has only done 150k KM - which is just 93k miles.
Is my failure due to age rather than wear and 'tear'?
Actually - to be honest - I say 'tear' above - but the pun is intended as it's all been fixed under warranty - so not to many tears here.
They are also doing the water pump and the starter under warranty - so my tears are actually a little smile.
$900 NZD ($540 USD) for the lot. Score!
But the question remains - even though it's well lubricated - do Rear Main Seals need replacing simply because of age?
I'm a little put out in that the truck has only done 150k KM - which is just 93k miles.
Is my failure due to age rather than wear and 'tear'?
Actually - to be honest - I say 'tear' above - but the pun is intended as it's all been fixed under warranty - so not to many tears here.
They are also doing the water pump and the starter under warranty - so my tears are actually a little smile.
$900 NZD ($540 USD) for the lot. Score!
But the question remains - even though it's well lubricated - do Rear Main Seals need replacing simply because of age?
