We have a Ford Mondeo made end of 1994 and it is due for a service. The person at the Ford dealer (probably a secretay NOT a mechanic) said that over time water would get in to the brake fluid and so it should be changed. It sounds like they are trying to make more money. Is it possible for this to happen?
2006-12-11 19:51:02 · 23 answers · asked by roly 3 in Cars & Transportation ➔ Car Makes ➔ Ford
If that was a secretary that told you that, she's one smart cookie!
Yes, water can get into brake systems. Brake fluid is hygroscopic, meaning that it has an affinity for water. Simply opening the brake reservoir will cause a bit of moisture from the air to be absorbed into the system. Mind you, opening it once won't be a matter of concern, but if you're the type who opens the reservoir weekly to check the level you WILL pick up quite a bit of moisture over time.
Most brake reservoirs are translucent so that you can see the level without opening it. Never open the reservoir unless you are adding fluid -- but you shoud never need to add fluid. If the level is low, your brakes need immediate professional attention. As long as the level is above the MIN mark, you're OK. Do NOT top off the level! If you do, when the brakes are serviced it will overflow and can damage your car's finish.
One problem with getting moisture in the brake fluid is that it lowers the boiling point of the brake fluid. If brake fluid boils, it will lose its effectiveness and you'll have pretty much NO brakes.
Another problem with getting moisture in the brake system is that it accelerates the corrosion of the brake lines from the inside out. External corrosion is pretty easy to spot, but internal corrosion won't rear its head until the line ruptures. Of course, brake lines only rupture when you need them the most -- when you need to stop your car.
Some high-end manufacturers -- Mercedes for example -- require the brake fluid to be changed every 2 years or so. That's wise practice even if the manufacturer doesn't recommend it.
One last comment. If you ever need to add brake fluid, you must only add it from a freshly opened container. Immediately discard any unused fluid. A good shop will discard opened containers of brake fluid after 48 hours at most. The best ones open a new container for each job and discard the unused fluid straight away.
2006-12-11 23:34:58 · answer #1 · answered by Bostonian In MO 7 · 0⤊ 0⤋
Whoever told you that was entirely correct. The crux of the matter is the brake fluid is hygroscopic, which means that it attracts water like a magnet attracts iron filings. It only attracts it in minute amounts through condensation, but over the course of several years, it builds up to a point at which it becomes dangerous.
It will affect braking performance eventually. because water boils at 100° C and brake fluid doesn't boil until about 400°C you get seperation (brakes can easily get to 300° C) and this gives you a spongy pedal feel and loss of performance.
It also won't do your hoses any good at all, it'll corrode them. If you look at most cars service requirements, they normally recomend you change it after something like 5 years ro 60,000 miles. And as car manufacturers, they tend to know about these things.
It's not expensive, fluid is only about £10 and it'll only take a garage half an hour to change it. If you're planning on keeping the car for a hwile definitely get it done. Skimping on maintanence is the reason cars breakdown more than anything.
We have a 1995 2 litre Mondeo here where I work that the company keep as a spare for emergencies for the staff. It's been serviced correctly it's entire life and it's now knocking on 180,000 miles and still runs a treat. If looked after, mondeos will go to intergalatic mileages.
2006-12-11 21:22:43 · answer #2 · answered by Steven N 4 · 0⤊ 0⤋
Brakes are a closed system, so unless you left the top off the filler during a rain storm, I don't see how.
But brake fluid does break down, and should be changed occasionally. Best test is to look. You know what brake fluid should look like, what does yours look like?
If you have ever had a wheel cylinder or master cylinder fail, you probably got new fluid then with the repair. Most manufacturers don't give a recommended interval to change brake fluid, just to check and top off if needed.
That being said, I suppose condensation could introduce some water in the system, which would lower the boiling point of the brake fluid and lead to some problems on heavy stopping.
One of the racing forums has this to say...
Brakes
About every other year, but certainly more often if you road race, you'll want to completely flush and replace your brake fluid. To do this, you bleed as normal, but rather than simply bleeding out the air, you bleed each caliper until new fluid comes through. This is easy to see, as the old fluid will be dark colored, whereas the new fluid is clear. Make sure to regularly check and re-fill the reservoir, so you don't suck air into the lines. Do them in the same order as you bleed.
2006-12-11 20:05:49 · answer #3 · answered by oklatom 7 · 0⤊ 0⤋
Water In Brake Fluid Reservoir
2016-11-01 08:54:18 · answer #4 · answered by kincade 4 · 0⤊ 0⤋
Yes with heat and condensation, water can develop on inside of brake fluid reservoir. It does no harm to change brake fluid regularly (every 10-12000 miles). If your brake fluid also supplies the power steering, which it does on some models, maybe do it even more often. However, driving a 1994 Mondeo? I would consider a new car. The brake fluids probably worth more than what you're driving.
2006-12-11 19:55:34 · answer #5 · answered by Anonymous · 2⤊ 0⤋
Water can get into the brake fluid.
The problem is not so much that is can dilute it, but that it boils at 100°C - much lower than brake fluid boils.
If there is water in the fluid, when it boils it forms bubbles in the fluid. These bubbles are compressible, absorbing the movement you make at the pedal without applying the brakes further.
Brake fluid should usually be changed every 3 years to keep the water content low.
2006-12-11 20:53:30 · answer #6 · answered by Neil 7 · 0⤊ 0⤋
I give the answer from drawings, above, top marks since he is absolutely correct. However, he omitted to point out that it depends on the brake fluid being used. DOT 4 fluid is hygroscopic and absorbs moisture from condensation leading to corrosion and impaired braking. DOT 5 fluid is non hygroscopic. However, if the car has been using DOT 4 do NOT change to DOT 5 since it will cause the rubbers in the brake system to swell with potential catastrophic consequences. Get the fluid changed as recommended in the service manual.
2006-12-11 22:46:54 · answer #7 · answered by lynxd67 2 · 0⤊ 0⤋
Have it done. It's usually on the service schedule for a reason. The reason is, over time hydraulic fluid can pick up water from condensation. That water can seriously damage the system through corrosion. Also, if the water gets too much, when braking hard it can turn to steam - result, no brakes!
Better safe than sorry!
2006-12-11 20:44:23 · answer #8 · answered by champer 7 · 0⤊ 0⤋
The answer is yes brake fluid is hygroscopic in other words it can and will absorb moisture from the atmosphere.The person you spoke to was correct if you did not change it the water in the fluid would lower the temperature at which the fluid boiled.Result could be an accident . Regards Mick UK.
2006-12-12 03:46:28 · answer #9 · answered by mick 6 · 0⤊ 0⤋
I doubt if your brake fluid has enough moisture in it to cause any loss of performance (compressibility) but if you are not hurting for money having your fluid replaced is a good idea. I change mine out on my pickup about every 50K miles and on my motorcycle about every 25K miles. It is much cheaper that replacing your components if corrosion does occur. You can do it yourself if you have any mechanical ability at all and a buddy to help. It only takes a quart of Dot 3 fluid and about 20 minutes. Your local Checker dealer can tell you how.
2006-12-11 20:06:00 · answer #10 · answered by Anonymous · 0⤊ 0⤋