New tools!

[someotherguy]

Neat tool and you just reminded me to check my trucks - thanks. I believe the water absorption is something like 1.5%/year leading to vapor lock with increasing water Unfortunately, the digital probes available are usually not very accurate. The good news is if you are lucky enough to get one that at least provides somewhat repeatable values you can use a correction factor to get a more accurate number. Just prepare a 1, 2, and 3 % standard solution of water and brake fluid (New container of brake fluid) and take triplicate readings and use the average to correct the values. Take a reading from the vehicle in question and correct up or down depending on the range of the value. Why go through all this trouble? 3% appears to be the wet limit and the range of the digital probes is narrow (1-3??) .
Detecting water in any type of matrix is difficult. With brake fluid, a KF procedure is used which basically purges the the water from the fluid and measures the amount directly. There’s always the colorimetric option - strips made by Phoenix Systems that test brake fluid and coolant. What do they recommend for cleaning in between readings?

Good info and I believe some of it went a little over my head - wasn't sure what a KF procedure is, so I had to go look it up. Hadn't heard of Herr Fischer before. I'm not sure the good folks over in China that made my tester had heard of him, either. They certainly didn't provide much documentation with my tester, not even what type of batteries it needed. For cleaning the probe, I just wiped it off with a paper towel. At this price point, I figure it's much less of a serious professional tool (despite the word "Profession" being used in the description), more of a simple general info device. Kind of like comparing a test light to a digital multimeter.

Excellent point about comparing to a new container. I should give that a shot when I get ready for next round of flushing so I've got a test container that is freshly un-sealed. What would you recommend for cleaning the probe, as the contacts are mounted in a piece of unknown plastic, with an LED between them. I'd hate to use something like brake parts cleaner and damage anything. Tempted to try isopropyl alcohol. Something that you would expect it to clean, then evaporate..

Richard

 

[Supercharged111]

I love my stihl products. A lot of people don’t know but if you buy stihl fuel at time of purchase you get an extended warranty.

Which supposedly matched Husqvarna's regular warranty. Whatever came in the saw sure smelled good, but it's a damn site more expensive than mixing your own. I end up mixing it a smidge thicker than 50:1 just to be sure. I ended up clearing something like 1/4 acre of trees, dealing with all the brush, and some of the stumps. This thing is an asskicker to run all day for 2 weeks straight so the saw that got a lot of time was the mighty Poulan Wild Thing. There were a lot of small trees that simply didn't need the bigger saw. The half dozen or so 70 footers though were much easier to limb and buck with the Stihl, I just had to suck it up and embrace the extra sweat.

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I started with a complete canopy of trees, and this doesn't quite show the extent of what was cleared. Not to mention the driveway we opened up mostly by mowing down a bunch of ferns and saplings. The truck has been pulled through a clearing in the trees behind it, we'll widen that out a bit next year. I can't wait. Probably gonna grab an MS261 before we go back, I used the 362 less than I thought I would due to its weight.

 

[JDGMC]

Good info and I believe some of it went a little over my head - wasn't sure what a KF procedure is, so I had to go look it up. Hadn't heard of Herr Fischer before. I'm not sure the good folks over in China that made my tester had heard of him, either. They certainly didn't provide much documentation with my tester, not even what type of batteries it needed. For cleaning the probe, I just wiped it off with a paper towel. At this price point, I figure it's much less of a serious professional tool (despite the word "Profession" being used in the description), more of a simple general info device. Kind of like comparing a test light to a digital multimeter.

Excellent point about comparing to a new container. I should give that a shot when I get ready for next round of flushing so I've got a test container that is freshly un-sealed. What would you recommend for cleaning the probe, as the contacts are mounted in a piece of unknown plastic, with an LED between them. I'd hate to use something like brake parts cleaner and damage anything. Tempted to try isopropyl alcohol. Something that you would expect it to clean, then evaporate..

Richard

Not over your head at all - you got it! IPA is a good choice based on solubility with brake fluid and evaporative properties. The two are key for repeatable measurements. The drying technique of your probe is probably the most critical step. Dry it a couple of different ways and use a magnifier to look at the end of the probe over time and you will know the best technique and how long to wait before taking your next measurement. Jot down your DOE (Design of Experiments) and fill in the data. Keep in mind these type of devices are conductivity meters. Temperature, brake fluid additives, and metals will certainly affect the readings. Report back on what you find with that particular model.

Good info and I believe some of it went a little over my head - wasn't sure what a KF procedure is, so I had to go look it up. Hadn't heard of Herr Fischer before. I'm not sure the good folks over in China that made my tester had heard of him, either. They certainly didn't provide much documentation with my tester, not even what type of batteries it needed. For cleaning the probe, I just wiped it off with a paper towel. At this price point, I figure it's much less of a serious professional tool (despite the word "Profession" being used in the description), more of a simple general info device. Kind of like comparing a test light to a digital multimeter.

Excellent point about comparing to a new container. I should give that a shot when I get ready for next round of flushing so I've got a test container that is freshly un-sealed. What would you recommend for cleaning the probe, as the contacts are mounted in a piece of unknown plastic, with an LED between them. I'd hate to use something like brake parts cleaner and damage anything. Tempted to try isopropyl alcohol. Something that you would expect it to clean, then evaporate..

Richard

Not over your head at all - you got it! IPA is a good choice based on solubility with brake fluid and evaporative properties. The two are key for repeatable measurements. The drying technique of your probe is probably the most critical step. Dry it a couple of different ways and use a magnifier to look at the end of the probe over time and you will know the best technique and how long to wait before taking your next measurement. Jot down your DOE (Design of Experiments) and fill in the data. Keep in mind these type of devices are conductivity meters. Temperature, brake fluid additives, and metals will certainly affect the readings. Report back on what you find with that particular model.

 

[95burban]

Which supposedly matched Husqvarna's regular warranty. Whatever came in the saw sure smelled good, but it's a damn site more expensive than mixing your own. I end up mixing it a smidge thicker than 50:1 just to be sure. I ended up clearing something like 1/4 acre of trees, dealing with all the brush, and some of the stumps. This thing is an asskicker to run all day for 2 weeks straight so the saw that got a lot of time was the mighty Poulan Wild Thing. There were a lot of small trees that simply didn't need the bigger saw. The half dozen or so 70 footers though were much easier to limb and buck with the Stihl, I just had to suck it up and embrace the extra sweat.

You must be registered for see images attach

You must be registered for see images attach

I started with a complete canopy of trees, and this doesn't quite show the extent of what was cleared. Not to mention the driveway we opened up mostly by mowing down a bunch of ferns and saplings. The truck has been pulled through a clearing in the trees behind it, we'll widen that out a bit next year. I can't wait. Probably gonna grab an MS261 before we go back, I used the 362 less than I thought I would due to its weight.

Beautiful. That’s a lot of hard ass work.

 

[someotherguy]

Not over your head at all - you got it! IPA is a good choice based on solubility with brake fluid and evaporative properties. The two are key for repeatable measurements. The drying technique of your probe is probably the most critical step. Dry it a couple of different ways and use a magnifier to look at the end of the probe over time and you will know the best technique and how long to wait before taking your next measurement. Jot down your DOE (Design of Experiments) and fill in the data. Keep in mind these type of devices are conductivity meters. Temperature, brake fluid additives, and metals will certainly affect the readings. Report back on what you find with that particular model.

OK, so I didn't go nuts with the experiment (so far) as I was busy trying to get my wife's brakes fixed and truck back on the road.. and her out of MY truck!

Original checking of old, gross-looking fluid showed a roughly 2.5% water content, or, "6 bars" on the graph, just below the "warning" indicator.

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After replacing the master cylinder and booster (both absolutely bad) and filling reservoir of new m/c with fresh brake fluid, then 15-20 minutes of test driving with lots of hard braking, you'd think there *might* be some mixing of new/old fluid, maybe, maybe not. Reservoir fluid still looks very, very clean. Tester probe has been cleaned with IPA and dried off. Tried the tester in the reservoir anddddd... same reading.

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Cleaned and dried the probe again and tried it in a brand new, freshly un-sealed bottle of brake fluid. I mean I just peeled the seal off minutes before testing. Same result.

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Starting to get the idea this tool has limited use, LOL.. what's funny is I have seen people using the simpler version that just has basic go/no-go LED indicators and they've supposedly detected bad fluid that needed replacing. Either those testers are more sensitive (or read incorrectly), or those vehicles had severely contaminated fluid.

Not pictured, I did try leaving the tester on while cleaning the probe with a paper towel wet with IPA just to see if I'd get a different reading. Yep, it went off the chart nuts and was beeping the alert at me. So at least it is capable of different readings.

Richard

 

[Schurkey]

After replacing the master cylinder and booster (both absolutely bad) and filling reservoir of new m/c with fresh brake fluid, then 15-20 minutes of test driving with lots of hard braking, you'd think there *might* be some mixing of new/old fluid, maybe, maybe not. Reservoir fluid still looks very, very clean.

Why not flush the entire system?

The worst, most-contaminated fluid is usually found at the lowest point in the system--the wheel cylinders.

 

[someotherguy]

Why not flush the entire system?

The worst, most-contaminated fluid is usually found at the lowest point in the system--the wheel cylinders.

Separate subject from discussing the tool, but yes. The whole system does need flushing. I also need to obtain a scan tool capable of bleeding the ABS unit, as my cheapo apparently does not do trucks this "old" (2006).

To elaborate, the whole idea behind testing the fluid was an attempt to measure just how bad it might be, as an insight into the cause of the brake problems. Instead of just tossing the old fluid out on a guess - albeit a calculated one - since we do know the fluid goes bad and needs replacing. Not a point of contention at all.

Richard

 

[Supercharged111]

Separate subject from discussing the tool, but yes. The whole system does need flushing. I also need to obtain a scan tool capable of bleeding the ABS unit, as my cheapo apparently does not do trucks this "old" (2006).

Richard

Could always delete the ABS like a real man.

 

[someotherguy]

Could always delete the ABS like a real man.

I mean, I could do it the "easy" way but it would still need to be bled. Unless I wanna get messy and get in there re-plumbing the thing out. Many gmt800's need all new brake lines by now anyway due to poor materials rusting out, but since we're not in a rust area, the lines are still tip-top. Hmm, maybe bend up some little "jumper" couplings.. lol. Nah. It's staying, until it's no longer serviceable.

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Richard

 

[JDGMC]

OK, so I didn't go nuts with the experiment (so far) as I was busy trying to get my wife's brakes fixed and truck back on the road.. and her out of MY truck!

Original checking of old, gross-looking fluid showed a roughly 2.5% water content, or, "6 bars" on the graph, just below the "warning" indicator.

You must be registered for see images attach

After replacing the master cylinder and booster (both absolutely bad) and filling reservoir of new m/c with fresh brake fluid, then 15-20 minutes of test driving with lots of hard braking, you'd think there *might* be some mixing of new/old fluid, maybe, maybe not. Reservoir fluid still looks very, very clean. Tester probe has been cleaned with IPA and dried off. Tried the tester in the reservoir anddddd... same reading.

You must be registered for see images attach

Cleaned and dried the probe again and tried it in a brand new, freshly un-sealed bottle of brake fluid. I mean I just peeled the seal off minutes before testing. Same result.

You must be registered for see images attach

Starting to get the idea this tool has limited use, LOL.. what's funny is I have seen people using the simpler version that just has basic go/no-go LED indicators and they've supposedly detected bad fluid that needed replacing. Either those testers are more sensitive (or read incorrectly), or those vehicles had severely contaminated fluid.

Not pictured, I did try leaving the tester on while cleaning the probe with a paper towel wet with IPA just to see if I'd get a different reading. Yep, it went off the chart nuts and was beeping the alert at me. So at least it is capable of different readings.

Richard

Good data and thanks for sharing. Helps people make an informed decision on what they are buying and the value of having this type of detector. Unless the fluid is completely saturated the sensitivity is very poor. The better choice is a boiling point tester, but more expensive. In the end, you change the fluid and you know it’s better than before just by simple observation, and that costs nothing. Changing the brake fluid periodically is what we do. How often is the real question? DOT3 more often than DO4. Even more often when located in a humid part of the country.