Using saved Brake Fluid

Status
Not open for further replies.
Joined
Sep 24, 2005
Messages
1,008
Location
Indiana
I know that brake fluid absorbs moisture and we always want to use fresh fluid, but I have a situation that I'm curious about and would be interested in others' opinion.

A couple of years ago I flushed the brakes in one of my cars using ATE 200 fluid. I used one can and only about 15% of a second one. I screwed the cap on the second can tightly as soon as I poured out what I needed. I then put that can in a ziplock bag and then that into a second ziplock bag and have kept it in my basement for a couple of years (pretty constant temperature of 65 F and 50% humidity).

How much do you think the fluid has been "compromised". I know that PE ziplock bags are far from being totally impervious, but would two be effective in preventing any further moisture absorption in the closed can? Also, I now have some mylar ziplock bags at my disposal and wonder if using one of those would be more effective for future storage.

I don't have a huge problem with throwing out the saved brake fluid, but if it can be saved effectively I'd prefer to avoid waste.
 
I simply screw the cap back on and use it until it's gone. I never gave a second thought to whether or not it has absorbed moisture. Oh, the humanity! YMMV
 
Originally Posted By: DBMaster
I simply screw the cap back on and use it until it's gone. I never gave a second thought to whether or not it has absorbed moisture. Oh, the humanity! YMMV


+1. Use it up.
 
I think I'll do just that. I'll put the 'open' fluid in my secondary car and use new for my main vehicle (they're still old by most standards, LOL).
 
I do the same, put it in a freezer zip bag after sealing. I use it up like that for many decades now and never had an issue.
 
ATE comes in a metal can, so it is fine
smile.gif


The issue is with plastic bottles
crazy2.gif
 
On the same note, if you run the car at the track and do some heavy braking then that fluid is going to heat up. Will that cleanse the brake fluid of moisture?
 
Have never found a place that will take brake fluid. Mention brake fluid at a hazardous material collection event and eyeballs roll around like you have the plague.
sick.gif
 
Originally Posted By: Reddy45
On the same note, if you run the car at the track and do some heavy braking then that fluid is going to heat up. Will that cleanse the brake fluid of moisture?
No.
http://tiltonracing.com/brake-fluid-stay-safe-and-go-fast/
Quote:
When the brake fluid becomes saturated with water (3.7 percent by volume), that water can boil in the lines and produce steam (the gaseous form of water). Unlike a liquid, a gas is highly compressible. To some [sic] this up, when a compressible substance (steam) is introduced into a hydraulic system (the brakes), that system can no longer function and the pedal will likely go to the floor –not good! Replacing the fluid before it becomes saturated with water (which we will touch on later) is the key to maintaining the dry boiling point. . . .
 
I guess I should have framed my question as : If your brake fluid has picked up moisture, could you heat it up (like in a clean pot) and cook off the moisture and then use it again in the car?
 
We are all happy to use fluid in a vented master cylinder reservoir for 2 years and in many cases much longer yet the fluid in a sealed can somehow deteriorates immediately on opening. That's a ridiculous notion, in a sealed can it has to last a lot longer than in does in the cars brake system.

The OP took good precautions and I think the fluid will be just fine. It could always be tested for moisture content if there was any concern.
 
Originally Posted By: Yah-Tah-Hey
Have never found a place that will take brake fluid. Mention brake fluid at a hazardous material collection event and eyeballs roll around like you have the plague.
sick.gif



You can mix it in with your used oil,trans fluid, ps fluid and gear oil.
 
Originally Posted By: Yah-Tah-Hey
Have never found a place that will take brake fluid. Mention brake fluid at a hazardous material collection event and eyeballs roll around like you have the plague.
sick.gif



That's goofy. They take it at our monthly collection events with no questions. I label my containers with a Sharpie to make it easy for them to fill out their sheets.
 
Last edited:
Originally Posted By: DBMaster
Originally Posted By: Yah-Tah-Hey
Have never found a place that will take brake fluid. Mention brake fluid at a hazardous material collection event and eyeballs roll around like you have the plague.
sick.gif



That's goofy. They take it at our monthly collection events with no questions. I label my containers with a Sharpie to make it easy for them to fill out their sheets.


Yeah, I think that's just him or his area. They took it fine on hazardous waste collection days around here. It's even listed as a substance that they take.
 
Originally Posted By: Hootbro
Bought one of these years ago and has paid for itself in testing both the fluid in the vehicle and any stored previously opened bottles I have had to reuse.


What has been your experience of testing stored fluid. Does it stay good for several years
 
Originally Posted By: barryh
Originally Posted By: Hootbro
Bought one of these years ago and has paid for itself in testing both the fluid in the vehicle and any stored previously opened bottles I have had to reuse.


What has been your experience of testing stored fluid. Does it stay good for several years


Longest I have tested a previously open bottle was two years on some store branded SuperTech (Wal-Mart) that initially tested at 0% water content new and was up to 1% water when rechecked. I still used it.

FWIW, I have also checked some new sealed Prestone branded DOT 3 that was 2% when first opened.
 
Status
Not open for further replies.
Back
Top