If the container is well sealed then it shouldn't make any difference. If its stored in a dry place i wouldn't give it a second thought if its a year or less.
Brake fluid after bottle is opened
- Thread starter paulri
- Start date
- Status
Originally Posted By: Vikas
Would you "intentionally" add few drops of water to the master cylinder? Adding brake fluid from opened bottle is essentially doing that and BITOGers cringe at that idea. I can't blame them.
How would that much water ever get into a bottle? It would have to be a big bottle left open for some time to accumulate that amount. 1 drop is ~1 ml.
Would you "intentionally" add few drops of water to the master cylinder? Adding brake fluid from opened bottle is essentially doing that and BITOGers cringe at that idea. I can't blame them.
How would that much water ever get into a bottle? It would have to be a big bottle left open for some time to accumulate that amount. 1 drop is ~1 ml.
Originally Posted By: SHOZ
1 drop is ~1 ml.
1 drop is about 1/20 ml. (Roughly 20 drops to the ml)
1 drop is ~1 ml.
1 drop is about 1/20 ml. (Roughly 20 drops to the ml)
Depends on the drop size! I have used 10gtts/ml, 15gtts/ml and 60gtts/ml drip tubing in my profession. :-D
Let's see, if a 500 ml bottle was half empty and opened in 15 deg C, 50% humidity air, according to a psychrometric chart you would have .005 grams H2O per gram air. Air weights .001225 g/cc and water 1 g/ml.
1 ml = 1 cc volume.
250 cc x .001225 g/cc x .005 g/g = .0015 g water added to bottle.
Let's say there's 20 drops/ml:
.0015 g water x 20 drops/ml / (1 g/ml) = .03 drops
or 1/33 of one drop, just to put it into perspective. Now, of course if it were left open for a significant time that would be different.
1 ml = 1 cc volume.
250 cc x .001225 g/cc x .005 g/g = .0015 g water added to bottle.
Let's say there's 20 drops/ml:
.0015 g water x 20 drops/ml / (1 g/ml) = .03 drops
or 1/33 of one drop, just to put it into perspective. Now, of course if it were left open for a significant time that would be different.
As noted most reservoirs are vented and be aware that the level cycles very slightly on every brake application due to the action of disk flexing pushing back on the pads slightly a few turns after pedal release. That breathing is going to equalize the humidity of the small volume of air in the reservoir to that of the surrounding air. So, in effect the fluid surface is continually exposed to humidity just like if the container cap was left off.
Originally Posted By: Kiwi_ME
So, in effect the fluid surface is continually exposed to humidity just like if the container cap was left off.
In that case, the location in which one's car is parked may be significant (i.e. a garage vs. outdoors, or Corpus Christi vs. DFW).
So, in effect the fluid surface is continually exposed to humidity just like if the container cap was left off.
In that case, the location in which one's car is parked may be significant (i.e. a garage vs. outdoors, or Corpus Christi vs. DFW).
Originally Posted By: Kiwi_ME
Let's see, if a 500 ml bottle was half empty and opened in 15 deg C, 50% humidity air, according to a psychrometric chart you would have .005 grams H2O per gram air. Air weights .001225 g/cc and water 1 g/ml.
1 ml = 1 cc volume.
250 cc x .001225 g/cc x .005 g/g = .0015 g water added to bottle.
Let's say there's 20 drops/ml:
.0015 g water x 20 drops/ml / (1 g/ml) = .03 drops
or 1/33 of one drop, just to put it into perspective. Now, of course if it were left open for a significant time that would be different.
I knew it could'nt be much...haha
Let's see, if a 500 ml bottle was half empty and opened in 15 deg C, 50% humidity air, according to a psychrometric chart you would have .005 grams H2O per gram air. Air weights .001225 g/cc and water 1 g/ml.
1 ml = 1 cc volume.
250 cc x .001225 g/cc x .005 g/g = .0015 g water added to bottle.
Let's say there's 20 drops/ml:
.0015 g water x 20 drops/ml / (1 g/ml) = .03 drops
or 1/33 of one drop, just to put it into perspective. Now, of course if it were left open for a significant time that would be different.
I knew it could'nt be much...haha
Are brake reservoirs vented only to let air out under pressure, or do they let air in? Most of the ones i've had, have a rubber extension that extends down as the fluid level drops. So do they really let air in?
Originally Posted By: Trav
Get a tester, if the humidity is low and the container is tight there is no reason to get rid of it but the only sure way of knowing is to test it.
This is also good for testing the fluid in the car to get a better idea of its condition.
There is one for DOT 3 and another for DOT 4.
http://www.amazon.com/gp/product/B00VX0L...rd_i=B005R3SSCM
Just how different can the condition of the fluid be between the samples tested at the master cylinder reservoir (where most/all check it), and the caliper pistons?
Get a tester, if the humidity is low and the container is tight there is no reason to get rid of it but the only sure way of knowing is to test it.
This is also good for testing the fluid in the car to get a better idea of its condition.
There is one for DOT 3 and another for DOT 4.
http://www.amazon.com/gp/product/B00VX0L...rd_i=B005R3SSCM
Just how different can the condition of the fluid be between the samples tested at the master cylinder reservoir (where most/all check it), and the caliper pistons?
Originally Posted By: spasm3
Are brake reservoirs vented only to let air out under pressure, or do they let air in? Most of the ones i've had, have a rubber extension that extends down as the fluid level drops. So do they really let air in?
Good point. That rubber insert certainly greatly reduces the amount of surface area exposed to the air. Essentially it's minimal if the level is at spec.
Are brake reservoirs vented only to let air out under pressure, or do they let air in? Most of the ones i've had, have a rubber extension that extends down as the fluid level drops. So do they really let air in?
Good point. That rubber insert certainly greatly reduces the amount of surface area exposed to the air. Essentially it's minimal if the level is at spec.
Well, that type you describe would be of the fully sealed variety and is the best situation. But I haven't seen one of those on a car in many years.
All German and Asian cars I've owned have vented reservoirs. The vent is often a nearly-invisible tiny cut in the center of the cap's rubber seal. In either case the fluid volume in the reservoir must be allowed to change with minimal pressure differential to the atmosphere.
I suspect it's a matter of cost, but with flushes specified every 2 or 3 years these days, perhaps it's hardly necessary to isolate the fluid from ambient humidity.
All German and Asian cars I've owned have vented reservoirs. The vent is often a nearly-invisible tiny cut in the center of the cap's rubber seal. In either case the fluid volume in the reservoir must be allowed to change with minimal pressure differential to the atmosphere.
I suspect it's a matter of cost, but with flushes specified every 2 or 3 years these days, perhaps it's hardly necessary to isolate the fluid from ambient humidity.
Originally Posted By: SHOZ
1 drop is ~1 ml.
It's not. It depends on the size of the drop, of course, but in the medical field one drop is standardized to be .05 ml. Therefore 20 drops = 1 ml.
1 drop is ~1 ml.
It's not. It depends on the size of the drop, of course, but in the medical field one drop is standardized to be .05 ml. Therefore 20 drops = 1 ml.
Originally Posted By: Vikas
Would you "intentionally" add few drops of water to the master cylinder? Adding brake fluid from opened bottle is essentially doing that and BITOGers cringe at that idea. I can't blame them.
I had been using opened 5-6 years brake fluid bottle many times without problem.
No, I don't intentionally add any drop of water to the master cylinder.
I tightly cap opened brake fluid container is as good or better than brake fluid in the system.
Would you "intentionally" add few drops of water to the master cylinder? Adding brake fluid from opened bottle is essentially doing that and BITOGers cringe at that idea. I can't blame them.
I had been using opened 5-6 years brake fluid bottle many times without problem.
No, I don't intentionally add any drop of water to the master cylinder.
I tightly cap opened brake fluid container is as good or better than brake fluid in the system.
- Status