Brake Fluid Contamination

A few weeks ago, by mistake, I added a few ounces of power steering fluid to my brake fluid reservoir. I have a 10 year old (year 2000) Plymouth Grand Voyager minivan. My owner’s manual states “Caution!. Do not allow petroleum base fluid to contaminate the brake fluid- all brake seal and components could be damaged causing partial or complete brake failure.” What should I do and what is an estimate price to fix my mistake?

I would use the old turkey boaster to suck everything you can out of the reservoir and then do a serious flush. If you have not flushed the brakes, you are past due anyway.

A recent caller had a similar situation but a shop put in more than a few ounces. Tom & Ray recommended replacing all the brake components, over $1,000. If you’re lucky, you can get those few ounces out of the reservoir.

Yes, it’s true, I have seen it before. A few weeks is a long time for this to be going on. Get that fluid out immediately and perform, or have performed, a brake fluid flush. If you go to a shop, tell them what happened and have them use twice the fluid they normally flush through the system. They will probably ask you to waive liability for any damages incurred as a result of the contamination, and understandably so. After flushing the brake system, drive very carefully and pay lots of attention to the feel of the brakes for the next few weeks. If you are extremely lucky, the flush will work and you won’t have any problems, but the odds are not in your favor. If components are damaged, expect to pay several hundred dollars to replace everything that contains rubber, and about a grand more on top of that if your van has ABS.

I would be surprised if a few ounces for only a few weeks would have the time and concentration to cause swelling and softening of the rubber components at the wheel cylinders. The master cylinder might be more likely to see any effects first.

You can periodically check the wheel cylinders for leakage by observing the backing plates in the rear for wetness and the calipers in front unless you have rear calipers too. Also, watch for a master cylinder fluid level drop. Master cylinder problem will most likely result in weakened but not totally failed brakes as you have a dual master cylinder.

You might be able to live with this but you then must inspect for a while; can’t skip that.

Don’t mess with this…Replace the master cylinder and then have the system flushed.