Alan C.

I have had caps on ATE blue crack after opening. I assume I have over tightened the cap. However, I have never had a brake fuid resovoir cap crack.

Professor Helmüt Tester

Then you're drinking the wrong kind of beer. Quality, not quantity.

Der Professor recommends 'cellared ales'. Search 'Allagash', 'Stoudts', 'River Horse' and maybe 'Middle Ages', if you're looking for some east coast craft brewers.

You can quote me: "If you're drinking cheap beer, then you probably deserve cheap beer".

kurt M

As was said I have been looking at this. I have a true boil point tester and have found it to be accurate. I test fluids when new to see that the tester reads in relation to the print on the can and have found them to be within 5 deg or so. This is spot on in relation to the 500 deg range we are working in. My recommendation is get a true boil point tester and stop guessing at all. Is it bad or not? Will a flush take care of the boil over I had? Test it and see. Takes 3 min and there are no consumables other than the sample so test all you like. If the fluid was compromised by moisture infiltration replacement will improve the condition. If it reads at or near the rated dry point you need to look at the system. Do toy have good cooling? You can also look at more boil resistant fluids as well as driving habits.
BTW The paper reactive test strips are useless in real world in proving age or contamination of fluid based the testing I read. There is no baseline to measure against and as all systems are a bit deferent the readings have no measured values to judge against. Most test for copper in the theory that copper is released when steel lines rust. Some lines have more copper alloy than others so a high reading in one car would not mean failed protection and a low reading in another car could be obtained when the line is about to perforate.

Opened 1/2 full metal can of ate blue stored on a cool dry shelf opened once a year to test has shown almost no lowering of boil point in over 3 years. HOW you perform you flushes would likely have a far greater impact of the boil point of the fluid in your cars system than the age of the clean fluid. I see a lot of misinformation on flushing and procedures and how effective they would be. As an example; a partial bleed of calipers is often done. This only moves the most moisture contaminated fluid that is in the reservoir further into the system. It is best to remove all the fluid in the reservoir and replace with fresh before proceeding with any release of fluid down line. Removing burned fluid form a caliper that has overheated is a good thing to do, moving lower boiling point fluid into it is not. A flush does not remove 100% of the fluid in any system. Flush, stir the fluids to blend and flush again for badly contaminated systems.

This looks at boil point only there are additives that protect the system but this is largely moot in our arena as we flush well before the fluids protective additives would be used up. Testing on this found that in most systems the corrosion protection portion of the fluid started to fall off after around 2 years. The moisture infiltration varied widely as outside temperature and humidity as well as other variables like system build and use are important factors.

Short answer. Let me know when you plan to pitch the cans. I'll help you carry them out

kurt M

i have never tested beer and never will as the test involves the distruction of the sample.

Cory M

Try drinking the brake fluid to see if it tastes watered down

Alan C.

If the tube is a carbon steel Bundy brake tube the copper is used to braze the tube in the production process as the tube is spiral wound. It is not an alloy added to the steel in this case. However, most steels will have trace amounts of copper which is considered a tramp element.

If one is searching for copper in the brake fluid I would suspect that the copper would be from the product of general corrosion at the brazed sites.

tkerrmd

Kurt, great post, thanks for taking the time!

tom

JasonAndreas

Factory OE brake lines from Porsche (even the new ones with the black polymer coating) are made from a copper-nickel alloy called Cunifer.

Alan C.

Jason,
Thanks for the information on the 'Cunifer' alloy. It is a far superior choice. With today's Ni curcharge rates it is an expensive alloy. However, considering what it is used for it is well worth it.

kurt M

Forgot that you are a Washington DC local. Feel free to stop by with some of the old cans and we can test it to see if there is any degradation of boil over limit. Another data point for the rest of us too.