# Polluted brake fluid

**URL:** <https://community.cartalk.com/t/polluted-brake-fluid/9240>\
**Category:** Maintenance/Repairs\
**Tags:** fluids, brakes\
**Created:** [January 10, 2008, 3:43pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240 "2008-01-10T15:43:33Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![go4vactn](https://avatars.discourse-cdn.com/v4/letter/g/51bf81/32.png) [@go4vactn](https://community.cartalk.com/u/go4vactn)\
**Post date:** [January 10, 2008, 3:43pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/1 "2008-01-10T15:43:33Z")

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My father put windshield wiper fluid in my brake fluid resevoir. How bad is this and what do I do to fix it economically?

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**Author:** ![Craig58](https://avatars.discourse-cdn.com/v4/letter/c/3da27b/32.png) [@Craig58](https://community.cartalk.com/u/Craig58)\
**Post date:** [January 10, 2008, 3:55pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/2 "2008-01-10T15:55:59Z")

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You need to flush out the brake system completely and put in fresh brake fluid. Windshield fluid is mostly water, which is very bad for brake systems. The brakes may not work correctly and it will cause corrosion. I would remove as much as possible from the fluid tank them completely bleed the system until the contaminated fluid has been replaced.

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**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [January 10, 2008, 7:06pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/3 "2008-01-10T19:06:42Z")

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I will only add that you should try to suck as much out of the reservoir as possible first.

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**Author:** ![Craig58](https://avatars.discourse-cdn.com/v4/letter/c/3da27b/32.png) [@Craig58](https://community.cartalk.com/u/Craig58)\
**Post date:** [January 10, 2008, 7:08pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/4 "2008-01-10T19:08:17Z")

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Absolutely, the less water that gets into the system, the better.

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**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [January 10, 2008, 7:30pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/5 "2008-01-10T19:30:15Z")

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I wanted to add that failure to follow these guys’ advice could easily lead to total loss of braking. Water can easily freeze and block a line, and if the fluid is “winter mix” it could attack the seals in the system.

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**Author:** ![Opera\_House](https://avatars.discourse-cdn.com/v4/letter/o/9dc877/32.png) [@Opera\_House](https://community.cartalk.com/u/Opera_House)\
**Post date:** [January 10, 2008, 8:09pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/6 "2008-01-10T20:09:14Z")

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Unlike most other fluids of the vehicle, water mixes perfectly with DOT-3 fluid. That water will quickly destroy an expensive ABS system. Effectively cleaning the brake system is likely beyond your ability.

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**Author:** ![JulioC](https://avatars.discourse-cdn.com/v4/letter/j/ea5d25/32.png) [@JulioC](https://community.cartalk.com/u/JulioC)\
**Post date:** [January 10, 2008, 8:23pm UTC](https://community.cartalk.com/t/polluted-brake-fluid/9240/7 "2008-01-10T20:23:29Z")

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No question, drain your break system through then 4 tires, then refill again with the good one.