10w - 30 or 10w -40

[embee 7,288]

Four years will be fine.

[alhendo1 3,043]

 

Not engine oil but discussion bearing similarities to the last few posts....discuss😅

[SteveThackery 3,090]

3 hours ago, alhendo1 said:

 

Not engine oil but discussion bearing similarities to the last few posts....discuss😅

 

Not very similar: engine oil isn't hygroscopic.  The guy starts out with a false premise: the majority of the water in brake fluid isn't absorbed from the air above the fluid in the reservoir, it's absorbed through the brake lines themselves.  Lots of polymers are waterproof but porous to water vapour (i.e. individual H2O molecules can get through).

 

My old employer - BT - uses polyethylene-sheathed cable and additional steps have to be taken to prevent moisture ingress.  This is usually air pressurisation on the primary side of the network, and grease-filled cables and joints on the secondary side.

[embee 7,288]

In a similar vein, some flexible fuel hoses can be porous to hydrocarbon molecules. Vehicles have to pass an "evaporative loss" test, where it is put in a test chamber ("SHED") and the amount of hydrocarbons given off when it is heated and cooled ("diurnal") is determined. The vehicle doesn't run during the test, it just stands stationary.

Loss through fuel hoses can be significant, and special low permeability constructions are available (at a price).

https://www.weiss-technik.com/en/productarea/sealed-housing-for-evaporative-determination-shed/

[alhendo1 3,043]

7 hours ago, SteveThackery said:

 

Not very similar: engine oil isn't hygroscopic.  The guy starts out with a false premise: the majority of the water in brake fluid isn't absorbed from the air above the fluid in the reservoir, it's absorbed through the brake lines themselves.  Lots of polymers are waterproof but porous to water vapour (i.e. individual H2O molecules can get through).

 

My old employer - BT - uses polyethylene-sheathed cable and additional steps have to be taken to prevent moisture ingress.  This is usually air pressurisation on the primary side of the network, and grease-filled cables and joints on the secondary side.

Thanks for posting......I watch some of his videos now and again and he seems to get good feedback/comments re his knowledge on whatever subject he's talking about....just to clarify....and I apologise for moving off topic....would you use brake fluid thats been opened for a bit...me personally for the little cost involved I'd just bi5y a new bottle.....just curious.

[embee 7,288]

I do use brake fluid which has been opened for a bit, but I always make sure the bottles are clean and the caps tightened fully while on the shelf. However, I do change the fluid regularly in all my fleet, at least every 2 years, so the bottles never sit there for all that long and new bottles get added to the shelf at regular intervals. 

Having thought about the subject before regarding the advice to use fluid from "sealed containers" I came to the conclusion they mean not open to the atmosphere, a tight screw on cap effectively means sealed, it doesn't have to be a hermetic foil seal (my interpretation anyway).

[DaveM59 1,605]

Whatever the oil or brake fluid is kept in and for however long, it will nearly always be better than the old mucky stuff you drain out.

[Tex 36,817]

6 hours ago, DaveM59 said:

Whatever the oil or brake fluid is kept in and for however long, it will nearly always be better than the old mucky stuff you drain out.

 

Excellent point! 

 

For the record, I simply can’t convince myself that new engine oils in sealed containers degrade with age. Anyone who has some they’re worried about using, send it my way. 

 

Brake fluid? Agree 100% with Murray. ‘Sealed’ container means one with a cap on, not one that’s not been previously opened. Some ‘Fancy Dan’ racing fluid the boss bought in Australia last year was £60 for 500 ml (no, I didn’t believe it either!) and I can promise you he doesn’t throw away a part used tin!  

[Guest uzi22]

1 hour ago, Tex said:

 

Excellent point! 

 

For the record, I simply can’t convince myself that new engine oils in sealed containers degrade with age. Anyone who has some they’re worried about using, send it my way. 

 

Brake fluid? Agree 100% with Murray. ‘Sealed’ container means one with a cap on, not one that’s not been previously opened. Some ‘Fancy Dan’ racing fluid the boss bought in Australia last year was £60 for 500 ml (no, I didn’t believe it either!) and I can promise you he doesn’t throw away a part used tin!  

 

Agree, and happy to share some unused stuff...  Double checked on the part bottle  of Motul 7100 and it’s stated: lifetime validity as long as stored sealed in a clean and dry environment.