Brake Fluid Replacment

<div class='quotetop'>QUOTE(Houston @ Jul 21 2007, 11:04 AM) [snapback]482836[/snapback]</div>

Toyota does not require it as a regular maintenance item. Sme people swear it is needed and others have never done it on previous cars. If you decide it is required Take it to a dealer brake service on a Prius requires the Toyota scanner, even to bleeding the brakes. There have been horror stories on this site of those who tried to do it themselves.

 

<div class='quotetop'>QUOTE(seasalsa @ Jul 21 2007, 12:12 PM) [snapback]482863[/snapback]</div>

Unless the brake fluid is a synthetic one, there will be a requirement to replace the fluid due to water absorption. The general rule of thumb is once every 2 years. Water absorption is not a function of brake system usage.

 

Good brake shops will have 'test strips' or a conductivity measuring device. If the Ffuid has 1% water or less, OK. If 2% water or more, change now. In-between results require a decision to be made.

I imagine that 2 years life applies to very humid environments. My Prius (mostly driven in the arid west) was on original fluid after 6.5 years and still dry enough.

Certainly the new model Prius needs THHT or similar for this brake work, but it may be just like conventional cars in the 2001-2003 model. Anyone know?

 

I don't know about the "classic", but with the current model, it's a bear of a job I hear. Even dealers who have done it have problems. I wouldn't take it to anyone else. Too "special".

BTW, if you use "synthetic" brake fluid (DOT 5 silicone brake fluid) you should change it -more often- than regular fluid. The reason is precisely that it doesn't absorb water. Some water always will eventually get in and it will go to the bottom of the system (calipers). There it will boil under heavy braking, rendering your braking useless. It will also corrode the calipers. Most race cars use this stuff, and they bleed their brakes very often, usually every race. With normal fluid when a little water gets in it is absorbed by the fluid and spread over the whole system, so it has less of an effect.

 

<div class='quotetop'>QUOTE(David Beale @ Jul 22 2007, 08:44 AM) [snapback]483142[/snapback]</div>

Silicone brake fluids were the first generation of synthetic brake fluid. There are other non-silicone synthetic brake fluids. ATE makes a product called Super Blue Racing Brake Fluid that is not silicone based. The requirement for bleeding after each race is more to keep the heat tolerance of the fluid at specification.

Given the unique-ness of the Prius' brake system, I would echo the suggestion to have any brake service done at the dealership. The amount that might be saved over the dealer's fee pales in comparison to the downside if the job gets screwed up and the brakes fail when you can least afford them to.