Brake fluid tester / testing ?

[TJ Hopland]

I have just become aware that there are fairly inexpensive brake fluid testers available.  Most of them appear to be called 'pens' and are about the size of a whiteboard marker (likely because they contain some sort of battery).  They appear to have a pair of probes on the end you stick in the fluid and I would guess are reading the moisture content. 

Since its the moisture that causes the corrosion and performance degradation that can be a good gauge of when it needs to be change and when its likely OK.   Most of the tools appear to have some sort of selector for the common types dot 3, 4, 5.  Many of the options seem to be in the $5-$25 price range including a few names that sound familiar.  I'm not saying Snap On or Craftsman but at least names I have seen or heard of in the automotive tool field over the last several years.  There also appears to be test strips that do the same thing?  I assume you dip those in the fluid and they then turn a color and you refer to some sort of chart to estimate the condition?

Anyone use or even heard of such tools being used?  Seems like they could be useful since conditions and usage vary quite a bit.  Changing brake fluid can be quite a project so you hate to do it if you don't need to but if things corrode that can really be a project not to mention the safety aspects so if there is reasonable way to test it seems like maybe a good thing?   

[Lexi]

Eagerly awaiting any replies as I would like to know myself. Clay/Lexi

[J. Gomez]

I have just become aware that there are fairly inexpensive brake fluid testers available.  Most of them appear to be called 'pens' and are about the size of a whiteboard marker (likely because they contain some sort of battery).  They appear to have a pair of probes on the end you stick in the fluid and I would guess are reading the moisture content. 

Since its the moisture that causes the corrosion and performance degradation that can be a good gauge of when it needs to be change and when its likely OK.   Most of the tools appear to have some sort of selector for the common types dot 3, 4, 5.  Many of the options seem to be in the $5-$25 price range including a few names that sound familiar.  I'm not saying Snap On or Craftsman but at least names I have seen or heard of in the automotive tool field over the last several years.  There also appears to be test strips that do the same thing?  I assume you dip those in the fluid and they then turn a color and you refer to some sort of chart to estimate the condition?

Anyone use or even heard of such tools being used?  Seems like they could be useful since conditions and usage vary quite a bit.  Changing brake fluid can be quite a project so you hate to do it if you don't need to but if things corrode that can really be a project not to mention the safety aspects so if there is reasonable way to test it seems like maybe a good thing?   

TJ,

I got one of the cheap tester just to check them up, the product claims to be compatible with all DOT 3, 4 and 5. I use it on all my vehicles our daily drivers (mine and my wife) as well as my 1956. Both my daily drivers (DOT 4 and 5) tested fine but my 1956 (DOT 3) was marginal so I flush the system.

The tester reminds me of those plant soil humidity testers so if there is water in the brake fluid reservoir it will register the % level. Now would I trust it to test the water content on the brake fluid "maybe" but not up to 100% since it still a water content tester not a fluid condition type tester.   

Since I just pay around $3 it goes with the say "you get what you pay for".      

[Lexi]

Jose thank you! Clay/Lexi

[39LaSalleDriver]

I've got one I bought off Amazon a few years back and check my fluid about twice a year. I've got no way to verify it's accuracy one way or another, but I've been pretty happy with it. I would certainly buy another if anything happened to mine.