Solvents and seal swell

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Over the years I have mentioned here that I don't care for High Mileage oils in young engines because I don't like the idea of softening or swelling seals that are not already worn.

I had not thought much about solvents swelling seals. However, today I ran into two examples that I thought I would share. One example relates to Neutra (from Bob) and the other relates to MMO (from a sales rep for MAC valves). I don't know whether either post relates to current elastomers. Since there seems to be a current resurgence for solvents in the sump, these links may be worth thinking about.


http://www.bobistheoilguy.com/sealconditioning/sealcondtioning.htm


http://www.macvalves.com/support/literature_files/MAC_lubircants.pdf
 
Uhhhh, not sounding so good for MMO. Good thing for me, i just put some in both my trucks. 4oz in each crankcase for the last 1k of the oil change. Both have a lot of miles and i dont use it regularly so im sure it will be fine.
 
Im not seeing anything relevant in the mac message. The bob study shows neutra as a good cleaner which may cause some swell, but this is a pure test, not a fraction of a quart in a multi-quart sump of oil.
 
That was dated 1995 and for air valve seals . Also, Is one mans opinion conclusive evidence. Not quite the same type seal and oil valve seal composition has changed over the last 15 years. Can you say ethanol. Lots of flaws if you are trying to say that mmo causes seal decomposition.
I will stick with the product for cleaning dirty crank cases because I know it works!!!!!!!
 
Originally Posted By: chad8
That was dated 1995 and for air valve seals . Also, Is one mans opinion conclusive evidence. Not quite the same type seal and oil valve seal composition has changed over the last 15 years. Can you say ethanol. Lots of flaws if you are trying to say that mmo causes seal decomposition.
I will stick with the product for cleaning dirty crank cases because I know it works!!!!!!!


Preventive measures with proper OCI will keep the crank case clean. I've found small engines with a carb system causing dirty crank case from excessive fuel or the nature of the beast with E-10 fuel may produce more deposits in the engine. But these are primitive comparing to modern day fuel injector vehicles.

If you got a dirty crank case why not prevent it from the start....are you lacking something~~~
 
From my point of view there are too many questions involving products such as MMO. Lots of potential issues like possibly dangerous chemicals, seal damage, breakdown of the product into harmful engine acids, disruption of oil viscosity, etc.

Heck, I have never used a solvent engine cleaner like Amsoil Engine Flush. But if I did try to clean an engine internally I think I would be much more willing to use Amsoil Engine Flush than MMO. I would assume that Amsoil Engine Flush has actually been tested somewhere. The product is DESIGNED to clean engines internally. It does not cost that much. You can locate an Amsoil dealer and buy a bottle of Amsoil Engine Flush.
 
Originally Posted By: chad8
That was dated 1995 and for air valve seals . Also, Is one mans opinion conclusive evidence. Not quite the same type seal and oil valve seal composition has changed over the last 15 years. Can you say ethanol. Lots of flaws if you are trying to say that mmo causes seal decomposition.
I will stick with the product for cleaning dirty crank cases because I know it works!!!!!!!


Sadly a lot of people believe Bobs tests no matter how they were done nor how old and outdated they are. His are certainly not scientific
 
Yea, but Bob was a great garage experimentor and I don't think he ever claimed any of his tests were scientific.

Much depends on the seal material as well. In the MAC Tech Bulletin, whatever their seal material, it did not play well in the sandbox with MMO. It also appeared that most ATF's faired well. I also wonder how MAC conducted their tests and under what conditions since they didn't state any?

FWIW, In this thread, I also did a semi-scientific test?

https://bobistheoilguy.com/forums/threads/seals.41199/
 
Originally Posted By: MolaKule
Yea, but Bob was a great garage experimenter and I don't think he ever claimed any of his tests were scientific.

Much depends on the seal material as well. In the MAC Tech Bulletin, whatever their seal material, it did not play well in the sandbox with MMO. It also appeared that most ATF's faired well. I also wonder how MAC conducted their tests and under what conditions since they didn't state any?

FWIW, In this thread, I also did a semi-scientific test?


Not to totally hijack the thread Molakule: But it relates to detergent/cleaning and seal leaks. I have several pieces of equipment that weep Rotella syn 5-40 HDEO , that slow or quit with Mobil 1 High Mileage 10w40, or a shot of bars stop leak. Given seals are bad, and I love Rotella.
Just curious if cleaning ability of HDEO has a role in this,if seal conditioners really work or some other factor. Noticed it in motorcycle, ATV and old lawn tractor. Any thoughts?
 
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Something I found over at the MMO site re seals. I thought it might be interesting:


Seals shink over time due to loss of plasticizer making them brittle. They also can develop microcracking. Using Marvel Mystery Oil rejuveniates the seals and re-swells them. However, it does effect a permanent cure and over time, the seals will again start to shrink. This may be over the course of one treatment without Marvel Mystery Oil or several. However, using Marvel Mystery Oil every time will keep the seals soft and at the proper swelling.


Some other info I dug up:
Marvel Mystery Oil has been tested on several elastomers (rubber) and plastic components without any degradation to the elastomers or plastics. These were very severe tests in which the rubber and plastic parts were immersed in Marvel Mystery Oil and placed in a 212 degree oven for 24 hours, 1 week and 1 month.

Also, Marvel Mystery Oil does not contain any acetone or ketone solvent.

IIRC they tested it with every product used in modern engine seals and found it to be harmless to them. HTH
 
I don't think that seal swelling oil additives will damage seals on their own. I am concerned that swollen, softened seal will wear faster wherever they are in contact with moving surfaces. A softer material pressed against a moving surface with greater force due to swelling just seems poised for greater wear. A good oil will be balanced to maintain seal pliability. Adding extra seal swell/softening in the absence of a need just concerns me. Over the years, my most common issue with engines have been seal leaks. I don't want to cause them to wear at faster rate.

I am not saying that either listed product will destroy your engine and I grant that the additive manufacturers say that they are safe.
 
I would have thought my 88 E-150 would have sprung leaks everywhere. It has two things working against it, age, and low miles from sitting for very long periods of time without being used. It is as leak free as it was the day it rolled off the line in 1987. It saw a lot of MMO over the years, and only fed synthetic oil after I logged about 5000 miles. Not sure what kept it leak free, but I'm very happy about it.
 
Aren't air controls valves made for a totally different environment than an engine?

I am surprised MMO is mentioned.
 
Originally Posted By: ZZman
Aren't air controls valves made for a totally different environment than an engine?

I am surprised MMO is mentioned.


MMO is widely used in air tools.
 
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