# Poured some brake fluid in power steering reservoir - need a flush? **URL:** \ **Category:** Factual Questions\ **Created:** [December 3, 2012, 6:38am UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829 "2012-12-03T06:38:34Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [December 3, 2012, 6:38am UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/1 "2012-12-03T06:38:34Z")
Friend poured about 3-4 ounces of brake fluid in his power steering fluid reservoir before he caught the mistake. Is that going to ruin the power steering? Does it need to be completely flushed and refilled, or is it no big deal? ---
**Author:** ![Seanette](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/seanette/32/9139_2.png) [@Seanette](https://boards.straightdope.com/u/Seanette)\ **Post date:** [December 3, 2012, 7:42am UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/2 "2012-12-03T07:42:52Z")
My DH (amateur DIY car guy) suggests consulting a mechanic. He thinks flushing and refilling very soon would be a good idea to avoid possible damage. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [December 3, 2012, 8:16am UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/3 "2012-12-03T08:16:31Z")
[Googling suggest all kinds of bad shit](http://answers.yahoo.com/question/index?qid=20070612194431AAESXnc)will happen if he does not get it out quickly, and with NO operation of the car at all. Oddly a turkey baster is suggested as the main removal tool. A hand cranked jackrabbit or hand drill drill pump might also work. ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [December 3, 2012, 12:12pm UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/4 "2012-12-03T12:12:45Z")
What kind of car is it? With most cars, simply siphoning or turkey basting most of the fluid out of the reservoir should _probably_ be okay. Some cars are really picky about their power steering fluid (notably Honda products) and so if he’s got one of those he might need to actually do a full flush to get as much of the contaminated fluid out as possible. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [December 3, 2012, 1:08pm UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/5 "2012-12-03T13:08:16Z")
Here’s Martha Stewart’s recipe for basting: > [@](#): > > Ingredients > > 1 turkey gizzard, chopped > 1 turkey neck, chopped > 1 turkey heart, chopped > 1 bay leaf > 1 teaspoon paprika > 1/2 teaspoon coriander > 1 clove garlic > Coarse salt and freshly ground pepper > 1 cup apple cider > **[Recipes by Ingredient](https://www.marthastewart.com/1520452/recipes-ingredient)** > > Looking for something to make with a bag of peaches? Maybe you have some pork in the freezer? What else can you do with white rice? Learn what to prepare and how to do it with these recipes by ingredient. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [December 3, 2012, 3:13pm UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/6 "2012-12-03T15:13:22Z")
> [@astro](#): > > [Googling suggest all kinds of bad shit](http://answers.yahoo.com/question/index?qid=20070612194431AAESXnc)will happen if he does not get it out quickly, and with NO operation of the car at all. That’s talking about power steering fluid in the brake system, not brake fluid in the power steering system. **HUGE** difference. Power steering fluid in most cars is typically interchangeable with common automatic transmission fluid (e.g. Dexron II or III) – some manufacturers even specify tranny fluid for the power steering. Hondas use their own special fluid, and regular PS fluid will damage the Honda PS seals. Many European cars use yet a different PS fluid, which as I understand is based on mineral oil. Brake fluid is a glycol. The seals used in brake systems will be damaged by petroleum oils such as motor oil, transmission fluid, and PS fluid. Brake fluid will dissolve paint – if it gets spilled on a painted surface of the car, get it off immediately, using aerosol brake cleaner or copious amounts of water (don’t use aerosol carb cleaner, which also dissolves paint). I’m in my 40th year of fixing cars professionally, but this is the first time I’ve run into this question, so I have to say I don’t have a definitive answer. I’m inclined to think that brake fluid is not likely to cause a problem in the PS system as I’ve never heard of brake fluid damaging any kind of seal, but I just don’t know if could harm some other components. If the engine hasn’t been run, it couldn’t hurt to empty the PS reservoir and put the right stuff in, and chances are that’s sufficient to avoid any problem. If the engine has been run, it’s probably pretty well mixed to where replacing the fluid in the reservoir won’t accomplish anything. To err on the side of caution, flushing the system may be the wise course. ---
**Author:** ![stanger](https://avatars.discourse-cdn.com/v4/letter/s/7ba0ec/32.png) [@stanger](https://boards.straightdope.com/u/stanger)\ **Post date:** [December 3, 2012, 3:16pm UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/7 "2012-12-03T15:16:15Z")
You need to get the system as flushed out as you can quickly. Remove as much fluid as you can from the reservoir with the turkey baster and add the correct fluid to it, at the very least. Better would be to remove the return line on the pump from the steering assembly, stick it in a bucket, and crank the engine on the starter for about 30 seconds to let as much fluid go into the system and push the old stuff out. Even if the pump emptys out during this time, such a short cranking won’t hurt it. Connect the system back up, fill the reservoir, crank some more and check the fluid level and add until nearly full. Run the car, steering the wheels back and forth a couple dozen times to help bleed air out of the system, and top off the fluid if needed. Had he only added a small amount, it would not have been a problem. Brake fluid is not much different from so-called Power Steering Stop Leak Fluid in that it causes the rubber seals in the system to swell up and get soft, which can temporarily help an old system. A lot of brake fluid will amplify this. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [December 3, 2012, 3:16pm UTC](https://boards.straightdope.com/t/poured-some-brake-fluid-in-power-steering-reservoir-need-a-flush/642829/8 "2012-12-03T15:16:42Z")
> [@Gary\_T](#): > > To err on the side of caution, flushing the system may be the wise course. For this reason I would just do it anyway.