BMW Luxury Touring Community banner

1 - 16 of 16 Posts

·
Registered
Joined
·
650 Posts
Discussion Starter #1 (Edited)
I have just done a little experiment inspired by something Drone said in reply to something I said in a discussion about ABS problems.
To set it up I poured some fresh Dot 4 into a small plastic container. The amount was 75 mils of Dot 4.
Into that I dropped water at 2 drops per test. The following photos will show the first photo tests as perfect, no moisture.
The second photo will show the dropper used.
The third photo will show the result after the first two drops of water added and it showed 1% but ok.
I took photos every 2 drops of water but I won't bore you with those. The next photo you see will be after 20 drops of water and it indicates a serious problem.
The last photo shows you the comparison visually of the volumes in question.
The actual amounts were as I said, 75 mils of Dot 4 and the water added which is indicated on the dropper by the two black lines is just a little under 1 mil of water.
This little experiment may help in decisions about how long you should potentially go before changing fluids. As you can imagine, the moisture content will play havoc with the internals of master cylinders and ABS units. The other thing you may notice is that from start to finish of the experiment the color of the Dot 4 did not change, it looked as fresh as fluid without moisture.
172113
172114
172115
172116
172117
 

·
Registered
Joined
·
526 Posts
I was considering one of these testers as well.
Or up my maintenance schedule from bi-yearly to yearly.
It's very humid here all year round (over 80%).
I've been consistent at every two years, but do it now every January for all of them.
It's cheap insurance.
 

·
Registered
Joined
·
289 Posts
Do I understand the numbers right? You started with 75 mils of Dot 4 and the meter went ballistic after adding 20 mils of water? I would've thought it would go nuts after, say, 4 drops of water which would be around 5%.

I wonder if there is a % where experts agree anything over that is unacceptable. Or a % where experts agree anything under that is OK?

Too late to Google that tonite. I'm going to bed.
 

·
Registered
Joined
·
650 Posts
Discussion Starter #4
Do I understand the numbers right? You started with 75 mils of Dot 4 and the meter went ballistic after adding 20 mils of water? I would've thought it would go nuts after, say, 4 drops of water which would be around 5%.

I wonder if there is a % where experts agree anything over that is unacceptable. Or a % where experts agree anything under that is OK?

Too late to Google that tonite. I'm going to bed.
No No. I started with 75mils of Dot4 and added 20 drops of water. Those 20 drops only equated to slightly less than 1 mil of water.
So that was 75 mils of Dot 4 contaminated with 1 mil of water.
I measured it all out carefully.
If you look at the very last photo I marked the start and finish point of the water in the dropper with 2 black marks. That was the visual representation of the 20 drops or 1 mil of water.
The meter first registered a water content after only the first 2 drops of water and that is represented in the third picture where the green light indicates 1%
It then took 20 drops of water to light up all the LED indicators. As predicted at around 10 drops the 2% indicator LED was Illuminated.
 

·
Registered
Joined
·
650 Posts
Discussion Starter #5
Here is the information on the side of the device and it would seem to indicate that up to 3% is tolerable but after 4% it's time to change the fluid.
172121
 

·
Premium Member
2020 R1250RT Alpine White
Joined
·
75 Posts
Wazza,

Sure seems like that device is sensitive enough but I'm not quite understanding the numbers.

By the end of the experiment you had mixed 1 ml of water into 75 ml of DOT4 fluid - it would seem to me that you would have a 1 ml/76 ml volumetric ratio which would be 1.32% concentration by volume wouldn't it? I don't know if not agitating the solution (if you didn't) makes a difference where the water tends (in the short term) to be absorbed into the upper layer of the DOT fluid or not.

It might be interesting if the ratio indicated on the device changes after the solution has been setting for a few days to try and equalize the overall absorption?

Anyhow, I sure appreciate the effort to actually put some bounds on the issue, thanks!

Larry
 

·
Registered
Joined
·
650 Posts
Discussion Starter #7
Wazza,

Sure seems like that device is sensitive enough but I'm not quite understanding the numbers.

By the end of the experiment you had mixed 1 ml of water into 75 ml of DOT4 fluid - it would seem to me that you would have a 1 ml/76 ml volumetric ratio which would be 1.32% concentration by volume wouldn't it? I don't know if not agitating the solution (if you didn't) makes a difference where the water tends (in the short term) to be absorbed into the upper layer of the DOT fluid or not.

It might be interesting if the ratio indicated on the device changes after the solution has been setting for a few days to try and equalize the overall absorption?

Anyhow, I sure appreciate the effort to actually but some bounds on the issue, thanks!

Larry
You make some very good points Larry. It was a hastily conceived and executed experiment. I was reading Drones comments one minute and within ten minutes I was downstairs mixing fluids to see what would happen. What I did was drop 2 drops of water into the Dot 4 and then agitate the container. Then I placed the tester into the fluid and waited. I then proceeded to do the same every two drops of water, each time agitating the fluid. It might be interesting to do another test where I place say, four drops of water in the Dot 4 and let it sit for a few days and then test it. I may find an entirely different response.
 

·
Registered
Joined
·
289 Posts
OK, I found something on the NHTSA website that explains how brake fluids are tested to determine compliance with government standards.


It's kinda long, but I found the section (Section 6.8) where water tolerance is tested by adding 3.5ml of water to 100ml of brake fluid. Then they freeze the sample at -40°F, then they heat the sample to +140°F. Then they test it--

6.8.4 Pass/Fail Criteria.
(a) At low temperature. (1) The fluid shall show no sludging, sedimentation, crystallization, or stratification; (2) Upon inversion of the centrifuge tube, the air bubble shall travel to the top of the fluid in not more than 10 seconds; (3) If cloudiness has developed, the wet fluid shall regain its original clarity and fluidity when warmed to room temperature;
(b) At 60 °C. (140 °F.). At At 60 °C. (140 °F.) (1) The fluid shall show no stratification; and (2) Sedimentation shall not exceed 0.15 percent by volume after centrifuging.


They don't actually say this, but reading between the lines it looks like brake fluid that's in compliance with NHTSA standards will still work OK if it absorbs up to 3.5% water by volume.

My take on all this is if my fluid is water-contaminated then definitely I should change it.

But no need freak out. o_O
 
  • Like
Reactions: nh1200c

·
Premium Member
2020 R1250RT Alpine White
Joined
·
75 Posts
My take on all this is if my fluid is water-contaminated then definitely I should change it.
But no need freak out. o_O
That's the feeling I am left with also, and it's always a banner day when I feel I've actually gained some real knowledge of how bad is bad! 😊 Between you bringing the DOT spec and Wazza bringing his lab notes I have very little concern now due in large part to the nice sensitivity of these inexpensive testing instruments and the specified resilience of the fluid itself to water absorption.

I guess the only thing that would be nice to know from a practical standpoint is how long a DOT4 brake fluid container could remain on a garage shelf after first use, but with cap tightened, before there was any issue (months, years)? And of course it will be easy to dip the tester into the bottle before use anyhow, so that's a good tool to put in the cabinet.

Please, both of you take the rest of the day off with pay! :LOL:

Larry
 

·
Registered
Joined
·
289 Posts
If you search on Amazon, they have a bunch of those testers. There's one for $12 that looks just like the one that Wazza is using. It got a 4.7 rating, adjusted to 4.2 after running it through the "fake review" website--

www.amazon.com/ITEQ-Liquid-Tester-Indicators-Calibrated/dp/B076SC377J/


There's also this one for double the price that got a 4.3 adjusted down to a 4.1--

www.amazon.com/Profession-Automotive-Motorcycle-Intelligent-Diagnostic/dp/B087RN3D6K


And this one for $20 that got a 4.0 adjusted down to 3.5--



Whenever I buy any kind of electronic or solid state device made in China, I figger my chances are 90% I'll get a good one. Which means 10% of the time I'll get a lemon, and the solution is to simply send it back for a different one. On Amazon you can do that for free. A lot of the 1-star reviews are from bozos who go ballistic because they got one of the 10%. That's just life. No need to go ballistic. Just send it back THEN write a review on the good one.
 

·
Registered
Joined
·
289 Posts
. . . I guess the only thing that would be nice to know from a practical standpoint is how long a DOT4 brake fluid container could remain on a garage shelf after first use, but with cap tightened, before there was any issue (months, years)? And of course it will be easy to dip the tester into the bottle before use anyhow, so that's a good tool to put in the cabinet.

Please, both of you take the rest of the day off with pay! :LOL:

Larry
Just last week I went to the local recycling center and dropped off $10 worth of Dot 4 that was in open cans. Checking my Amazon history, I bought that stuff 6 years ago. Probably a good idea to dump it, but I think I'm gonna buy one of Wazza's pens for $12. Yeah, I'm a big spender.

(I've heard that the only thing cheap on a BMW motorcycle can be found between the handlebars and the saddle.)
 

·
Registered
Joined
·
289 Posts
And not that anybody cares, but Prestone Dot 4 costs about $4.50 for 12 oz. at my local Walmart which works out to about $12.50 per liter. I buy this stuff on Amazon for $20/liter so I guess I'm not a true BMW rider. LOL --

www.amazon.com/gp/product/B003VXRPL0

172126
 

·
Wrencher Extraordinaire
2005 K1200LT
Joined
·
14,346 Posts
I only buy it in pints as I usually can flush an LT with just one pint. Quarts would be cheaper but I would end up tossing them in the high humidity of N. Alabama. If I only use part of the pint I also write the date opened on the bottle and pitch after a year, but now I have one of those testers so maybe not.
 

·
Registered
Joined
·
650 Posts
Discussion Starter #14
To answer another question about the little experiment. The Dot 4 I used was out of a half empty bottle that I had on the shelf from around 12 months ago. It tested perfect. I think as long as the cap is on tight you might be ok.
 

·
Registered
2003 BMW K1200 LT (88K on 2020/08/13)
Joined
·
84 Posts
Wazza and all:

Thank you for your testing, time and tutelage. I would assume that a sealed cap on a bottle is the same as a sealed reservoir, were not on taking water/humidity through metal/rubber container's or lines, it must be introduced through cylinder operation whether it be the brake caliper or the slave cylinder. I also bought a tester and after changing my clutch, I flushed all fluids, starting out fresh @ 90K.
 
  • Like
Reactions: nh1200c and DRONE

·
Premium Member
Joined
·
7,646 Posts
To answer another question about the little experiment. The Dot 4 I used was out of a half empty bottle that I had on the shelf from around 12 months ago. It tested perfect. I think as long as the cap is on tight you might be ok.
I have used brake fluid from sealed containers that were at least 8 years old with no issues. I generally don’t leave the container open even when doing flushes. I replace the cap each time I top up the reservoirs. If the container is well sealed, the only moisture in the bottle is what little is in the air above the fluid. Even in a high humidity area, I doubt that is enough moisture to add even 0.1% water to the fluid. Given how short the change intervals are on an LT, I have no problem putting such fluid in.
 
1 - 16 of 16 Posts
Top