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Fri 3 Nov 2023 18:19

Honda CR-V - Bake Fluid Shelf Life - macbook

Hi,

I have purchased in 08/2021 a two bottles of Comma DOT 4 Synthetic Brake Fluid. I used one, and the other one left untouched. I planning to flush the brake fluid soon, and just wondering if I should get a new bottle as the description on the bottle says the product has 3 years shelf life (expires) from date of manufacture.

The problem is I have looked around the bottle at least 5 times and there is nowhere a manufacture date (should be identified as an eight digit code printed on the bottle. YYYY.MM.DD.).

I have opened the bottle to test it with cheap ebay brake fluid tester pen and it's still shows as 0-1%, hence confused about this product shelf life.

The new 1L bottle of Comma DOT 4 Synthetic Brake Fluid cost around £8, so not a big deal, but just don't waste thing, if they still good. What do you think?

Thank you

Edited by macbook on 03/11/2023 at 18:26

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Fri 3 Nov 2023 18:34

Honda CR-V - Bake Fluid Shelf Life - Xileno

You will get a range of responses, from don't use it to it will be fine for another twenty years.

Personally for a modest £8 which is what some pints of beer are, I would buy a new one. Peace of mind is worth £8. You can also use the old fluid for something else - repurpose I think is the phrase or upcycle. It makes a great paint stripper if you are into model-making, as does Dettol surprisingly.

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Fri 3 Nov 2023 21:08

Honda CR-V - Bake Fluid Shelf Life - elekie&a/c doctor

If it’s an unopened sealed bottle, can’t see it being a problem. Brake fluid is hygroscopic .

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Fri 3 Nov 2023 23:27

Honda CR-V - Bake Fluid Shelf Life - Andrew-T

If it’s an unopened sealed bottle, can’t see it being a problem. Brake fluid is hygroscopic .

Agreed. The important thing is that the bottle (can?) has not been opened. Better still if it has been kept at a steady (low) temperature. Even though it is hygroscopic (tends to absorb moisture slowly) it usually does its job for years in a braking system, so I don't think you have any reason to get another.

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Sat 4 Nov 2023 00:12

Honda CR-V - Bake Fluid Shelf Life - edlithgow

I'd use it.

I keep my brake fluid bottles in multiple plastic bags which I fondly imagine will slow its water absorption.. If I have a dessicant sachet left over from anything I chuck that in as well.

I use DOT3 in preference to DOT4, less hygroscopic and cheaper, though getting hard to find.

Used (and coffee filtered)it makes a good carb cleaner.

Incidentally ALL brake fluid is synthetic, (there are no crude brake fluid wells in Pensylvania) so the use of that term to imply superior quality is marketing BS, carried over from motor oil marketing BS

Edited by edlithgow on 04/11/2023 at 00:16

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Sat 4 Nov 2023 09:54

Honda CR-V - Bake Fluid Shelf Life - Andrew-T

Incidentally ALL brake fluid is synthetic, (there are no crude brake fluid wells in Pennsylvania) ...

The oddball is silicone brake fluid, very different from the regular stuff, and used where the fluid has to be non-hygroscopic.

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Sun 5 Nov 2023 00:55

Honda CR-V - Bake Fluid Shelf Life - edlithgow

Incidentally ALL brake fluid is synthetic, (there are no crude brake fluid wells in Pennsylvania) ...

The oddball is silicone brake fluid, very different from the regular stuff, and used where the fluid has to be non-hygroscopic.

Well, thats "synthetic" too. The lack of water absorption might seem to be an advantage, and probably is in most circumstances (I believe its standard in US Army vehicles, for example) but it means that any water that does enter the system forms discrete droplets rather than dissolving. This could promote pitting corrosion, and it could also freeze, causing mechanical interference.

Possible exception to my "ALL brake fluid is synthetic" blanket statement might be the hydraulic oil used in some Citroens. I'd suspect this might be a mineral oil base rather than synthetic, though I dont know this for a fact.

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Sat 4 Nov 2023 11:00

Honda CR-V - Bake Fluid Shelf Life - madf

I used a 4 year old unopened bottle of brake fluid last time I changed the front pads and changed all brake fluid in 2021.. (I change fluid every 4 years)

No problems at all and passed three MOTs since..

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Sun 5 Nov 2023 01:01

Honda CR-V - Bake Fluid Shelf Life - edlithgow

I used a 4 year old unopened bottle of brake fluid last time I changed the front pads and changed all brake fluid in 2021.. (I change fluid every 4 years)

No problems at all and passed three MOTs since..

While I'd be pretty sure it was all right, at the risk of stating the obvious I'd just point out that "No problems at all and passed three MOTs since." is much less than a guarantee.

You could probably use tap water and get the same result.

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Sun 5 Nov 2023 09:07

Honda CR-V - Bake Fluid Shelf Life - bathtub tom

You could probably use tap water and get the same result.

I recall a rally car using orange juice (presumably not fizzy) from a spectator as a stop-gap measure.

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Sun 5 Nov 2023 16:38

Honda CR-V - Bake Fluid Shelf Life - John F

You could probably use tap water and get the same result.

I recall a rally car using orange juice (presumably not fizzy) from a spectator as a stop-gap measure.

Too acidic.... and wasteful. Why not wee?

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Mon 6 Nov 2023 03:48

Honda CR-V - Bake Fluid Shelf Life - edlithgow

You could probably use tap water and get the same result.

I recall a rally car using orange juice (presumably not fizzy) from a spectator as a stop-gap measure.

Too acidic.... and wasteful. Why not wee?

Probably used it all for Adblue substiture:Urea base, y'know?

Low salt high protein diet indicated. Like Atkins?

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