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Author Topic: Did I Throw Out Perfectly Good Brake Fluid?  (Read 3072 times)


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Did I Throw Out Perfectly Good Brake Fluid?
« on: June 28, 2013, 07:10:17 AM »
After reading one of the posts here about tragedy on the road, I decided to go over my engine checking fluids, belts, batteries, all the boring stuff I should be doing more often, but I don't do a ton of miles, so I get lazy.  I certainly know better, just busy or lazy at times.

My 23 years in the Caribbean taught me to constantly be vigilant about my boat and  jeep engines.  But there was no AAA or Coachnet or anyone to rescue you. If you got into trouble with your boat or car, you best get yourself out of trouble again. Now I am sick, old, tired, lazy and in America. 

On my little old Class C...
My brake fluid reservoir is installed on a slope, so the full line is not at all level. I am not sure what this means or exactly where the fluid should be. It appeared to me that I might need a dab of brake fluid for good luck.

I pulled out a brake fluid bottle that came with the RV. It seemed to slosh around like water. I thought I remembered brake fluid being a bit thicker. Because I've discovered a few goofy antics from the prior owners or their repair person, I thought I should inspect the fluid. I poured some into an empty coffee can and it was clear and liquid like water.

Well in the Caribbean, my brake fluid in one of my jeeps needed about a tablespoon a month. No one ever really found the problem, so it seemed cheaper to just keep it topped up. The brake fluid I bought there was always pinkish red in color.

So when I saw this brake fluid was clear and runny like water, I tossed it all out. I haven't been shopping to buy any more yet. No car, so I save up my errands and drive the wheel estate.

Now I heard a rumor that brake fluid can come in any color including clear.

So, did I just throw out perfectly good brake fluid?

Living, working. playing  in a 1992 Holiday Rambler Imperial 36' 5th Estate, formerly 8 years 24/7 in a Class C, 1994 Tioga Montara, 28'

Pack half the stuff and twice the cash.


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Re: Did I Throw Out Perfectly Good Brake Fluid?
« Reply #1 on: June 28, 2013, 07:52:34 AM »
Heh...you probably did.  But lucky for you, it's not that expensive.  I usually can't find the open bottle I know I have somewhere in my garage, or shed, or trunk, or ... somewhere.  So I go buy another one.  And when I top off my fluid, I set it right beside the other open bottle I couldn't find.
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Gary RV_Wizard

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Re: Did I Throw Out Perfectly Good Brake Fluid?
« Reply #2 on: June 28, 2013, 08:34:47 AM »
Brake fluid is typically rather thin, thinner than ATF or engine oil, and yes it can be most any color but tends towards clear, with an overtone of red or blue-black.

Brake fluid that has been stored awhile can accumulate moisture, so the pros recommend that you always use fresh stuff. Not very practical for us DIY folks, who only need an ounce or two once in awhile, but that's the professional advice. I just keep a can tightly sealed, and if I can't remember when I last used it, I toss it out and buy a new can next time.
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Lou Schneider

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Re: Did I Throw Out Perfectly Good Brake Fluid?
« Reply #3 on: June 28, 2013, 08:37:23 AM »
How old was that bottle, and how humid is your environment?  Brake fluid absorbs water from the atmosphere, which is why your master brake cylinder has those collapsable diaphrams on the lid.  They expand as the fluid level in the reservoir goes down when you press on the brake pedal, to keep moist outside air from being drawn in.

Water in the brake lines isn't good - when the brakes get hot the water in the brake lines near the wheels can boil into steam and make your brake pedal turn to mush.  It's why auto manufacturers recommend flushing the brake system every few years.

Yes, brake fluid can be clear, but if the can has been sitting in muggy air more than a couple of months I'd throw it out.


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Re: Did I Throw Out Perfectly Good Brake Fluid?
« Reply #4 on: June 30, 2013, 04:28:35 PM »
Yep, it's cheap.  If in doubt, throw it away. 

FWIW, I flush mine every two years.  I used a turkey baster to pull the master cylinder dry and refill with fresh. (you won't have to bleed it...just refill after you wipe it out).  Once it's full again, I gravity bleed it starting at the furthest wheel and ending at the nearest.  Just let it run until it's clear.  Ensure the master cylinder doesn't run too low.

Cheap insurance.  I've seen some cars where the brake fluid looked like tar. 
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Re: Did I Throw Out Perfectly Good Brake Fluid?
« Reply #5 on: July 01, 2013, 04:27:39 AM »
No you didn't waste good fluid. Brake fluid is like leftovers in th fridge, when in doubt throw it out. The full line denotes full with new brake pads and shoes. As the new pads wear, the caliper pistons move further out in their bores requiring more fluid to remain in the caliper. That is where your occasional tablespoon of fluid was going. Good idea to check the level now and then, level doesn't need to be full to top line at all times. I'll add when it's down almost half way. If fluid from bleeders is dark, it's time to flush, your steel brake lines are corroding internally when the fluid is dark. Most reservoirs hold enough fluid to make up the difference between shoe/pad replacement. Buy the smallest bottle of fluid available for topping off, buy the quarts when opening up the system for repair or bleeding.

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