Changing out brake fluid

Cigroller—I have driven and owned my own cars since 1950 and have done my own mechanic work and have never changed the brake fluid and have never had a problem with them, as far as I know. Same thing for power steering. I have never replaced a master cylinder or wheel cylinder either!! I guess God has been with me!!

My vechicle is a 2002 Chrysler Minivan. The manuals caution that if you replace a brake hose or caliper to tow tke van to a Chrysler dealer to have the brakes bled. About 5 years ago I took it to two local shops to see if they could replace the fluid.
Both said they could not because Daimler- Benz wouldn’t release the computer codes necessary to hold the valves in the ABS open so it could be bled.
I understand that the codes have since been released but I have no way of inputting the codes.

My owners manual says nothing about changing the brake fluid, and BTW, it reccomends changing the transmission fluid and filter at 60k IF you use it for a Police car, taxi or towing a trailer. Otherwise, it reccomends changing it at 120K miles. However, one can change it whenever one wants to.

With your Caravan or B-van there is a diaphragm on the reservoir cap that drops down as the fluid level drops (in theory) that isolates the fluid from the atmosphere. Japanese vehicles (and others) have vented caps and require brake fluid replacement every 3 years. On a Dodge you will get new brake fluid when you replace the master cylinder.

Nevada gives a great clue why some cars require frequent brake fluid replacement while other can live out their normal lifespans – factory to crusher – on their original brake fluid.

If your owner’s manual totally ignores brake fluid, so should you.


Can’t you bypass that problem by having an assistant in the vehicle with the car on and press the brakes. this would transfer the pressure through all brake lines (because it would apply the brakes) and you can intermittently bleed from the bleeder valves.

I changed out the brake fluid on my 02 outback recently and did it with this method.

Do you guys change the air in the tires regularily too?

A well respected local shops told me that without the computer codes to hold the valves in the abs open they had found out that they couldn’t bleed these brakes. One told me they had replaced a caliper and wound up having the van (a2001 Chrysler) towed to the dealer to bleed. I was told they released the codes a year or two later, but that doesn’t help the do-it -yourselfer.

My issue was that I was having a right front and left rear brake drag very intermittently, weeks apart. My brake fluid was very dark and full of black pieces of something that I figured were clogging one of the return ports in the master cylinder. I parked the van downhill and used a turkey baster to remove and replace all the fluid in the master cylinder with fresh and repeater the next 2 Saturdays. No more dragging brakes and it has been about 4 years.

I change the air in my tires pretty regularly, whenever I buy new tires.

I think it’s a good idea to start with fresh new air whenever I buy a new set of tires.

I never change the air in my tires even when I get new tires - its just a waste of money and pollutes the world unnecessarily with old, dirty air. Whenever I get new tires, my shop is under strict instructions to transfer the air from my old tires to the new ones.

It must really cheese you when you get a flat tire, and inadvertently waste all that air.

I put radon in my tires. The blue glow looks cool at night.

Do you guys change the air in the tires regularily too?

No…but I do change my oil regularly. Based on that question I assume you DON’T.

I think Elly was riffing on brake fluid, not oil.

I think Elly was riffing on brake fluid, not oil.

I know…I was trying to show his analogy was kinda stupid. Air in a tire is NOT the same as brake fluid in brake lines. A closer analogy would be oil in the engine since NOT changing either can result in damage.

I will begin to change air in my tires as soon as someone convinces me that it contributes to the vehicles reliability and/or longevity. I’ve yet to see such evidence.

Meanwhile, I rotate the air in my tires. Once for every turn of the wheel.

oldtimer11… just doesn’t make sense. If you turn the car on, take the parking brake off, hold the brake pedal down and it holds the car from moving, then there is pressure in the brake line and it you should be able to relieve it by opening the bleeder valve. The only way you would not be able to bleed them based on what you’re saying is if somehow the ABS system was connected to the actual bleeder valve itself, which I can’t think of a reason for.

I suggest you put the car on a jack, take a wheel off, have someone apply the brakes with the vehicle on and then you open the bleeder and see what happens. I bet fluid would come out. If it doesn’t work, then you’ve wasted only 10 minutes of jacking the car and taking the wheel off.

Nebin, you are on the right track. On Chrysler minivans calipers and wheel cylinders can be bled with the conventional method. If the master cylinder is allowed to run dry or the hydraulic control unit is replaced/takes in air the ABS system must be bled with the DBRIII scan tool. I have done alot of brake work on Chrysler products and rarely needed to bleed the ABS unit.

From the 2002 RS (Caravan) service manual;

The base brake’s hydraulic system must be bled anytime air enters the hydraulic system. The ABS though, particularly the ICU (HCU), should only be bled when the HCU is replaced or removed from the vehicle. The ABS must always be bled anytime it is suspected that the HCU has ingested air. Under most circumstances that require the bleeding of the brakes hydraulic system, only the base brake hydraulic system needs to be bled.

The van is now 12 years old and I live in a suburb of Buffalo NY. I am not going to try opening a bleeder that has been bathed in road salt for 12 years. You can try but the usual result is a bleeder that is broken off and the parts stores won’t accept then as a core. Then when you replace the caliper you try to separate the rubber line from the hard line the usual result is a broken hard line. You can’t flare a rust-pitted hard line so it has to be replaced back to the ABS controller. Try doing that without getting air in the ABS.
I am not new at this, between our cars, my kid’s cars and my grandkid’s cars I have done more than 50 brake jobs in the last 50 years with many of them being in rust buckets that usually had to be replumbed all the way back to the master cylinder. Still may be able to use my wheel cylinder hone on my 2004 PT with rear drums.

For the DIY person replacing the fluid in the reservoir every year or two may be good enough.

When removing a caliper or brake hose apply the brake pedal an inch or two with a prop rod (broom stick) while performing the work. This will block the master cylinder inlet ports and prevent the master cylinder/resevoir from draining.