$140 seems way to expensive to be justified at 32K. I have the fluid flushed when I have a brake job done. It's only a small additional charge since the system needs to be bled anyway. Of course, my driving is such that I only need brake service at 60K to 80k intervals.

 

Brake fluid naturally absorbs moisture from the air. At a 3% contamination the fluid boiling point drops to less than 275*F, this can cause a boiling of the fluid under HEAVY braking. Also and more important acids and other compounds form that can cause aluminum parts to corrode and pit. Small particles will also clog the small passages in the ABS system. that was the why. It takes about 2 years for the brake fluid to get to a 2% contamination. Most American manufacture do not have a fluid flush interval, most European manufactures do and that is every 2 years in the spring. If you flush your brakes every 2 years you will probably never have a hydraulic brake failure. If they are going to flush your brakes make sure they use a power bleeder. Depending on labor rates and area $80 to $140 is in the ball park, with $140 a little high. BTW Ford (factory) uses a high performance brake fluid that is a DOT 3 spec but acts more like a DOT 4 (higher boiling point) It would be nice if they used that fluid, but it is hard to find and more expensive that regular DOT 3 which can be used. HTH

 

I don't think so. Ever drive your car after it has sat for a few days, especially if it has rained and the rotors get that fine coat of rust on them? The first few stops you make will be nice and smooth down to 5 mph or so before the regen stops and you get launched into the windshield. I think regen does more then a lot of people realize, not less. JMO.

 

IMHO, I think alot of people get the idea, from descriptions like yours, that FEH braking is either all friction or all regen.....when in reality it is constantly a combination of the two. They see the dashboard indicators showing regen and they assume that all of the braking is being done in the generator, etc.(again, hypermilers aside)

The "grabby" brake condition that many folks have described is likely caused by the moisture, not rust, on the rotors. In non-hybrid/regen vehicles, this moisture is usually removed during the initial portion of a stop when the driver first begins to push the brake pedal. As the driver smoothly applies more and more pressure, the moisture quickly goes away and the end of the stop is predictable and smooth.

Perhaps, in the FEH, near the end of a normal controlled stop, the friction pads are told to assist the regen braking by gradually grabbing the rotor - but it is still somewhat wet - so the FEH isn't stopping as fast as the computer thinks it should be so it orders quicker engagment of the pads and bang.....you get the jerking right as you come to a stop. The pre-programmed gradual engagment of the pads is not stopping the FEH as fast as the driver and the BSCM have ordered, so the computer adds "too much" engagement too quickly. [sorry off thread topic]

 

It is normally a combination of both, I agree. I drive in "L" a lot and when I do I can definitely tell the difference how much more the regen does then when driving in "D". It may be the moisture, it may be the rust on the rotors that I see after letting the car sit for a week or two or it may be the computer control but in any way, these cars have some pretty sensitive brakes at low speeds sometimes. And I don't think any of these conditions warrant changing the brake fluid after 30k miles.

 

I absolutely agree.

 

IMMHO there is a much GREATER danger involved in having a dealer drain and flush your brake fluid/system. Dealers consider this job to be routine therefore a skilled mechanic or technician is NOT required.

"Routine" jobs/tasks are typically performed by young and inexerienced McD graduates.

Personally I think for most owners being more careful, a LOT more careful, in brake pad frictional material selection would be of much greater importance.

And finally....

Your brake system is extraordinarily well sealed against being contaminated. The only "opening" is via the filler cap and when that is installed the only thing left is a small opening in the cap to allow for equalization of any air pressure differential inside teh reservoir as the brake fluid volume rises and falls due to HEAT.

One of our local Porsche dealers often sponsors "free" track events. Free if you can certify that your brake fluid has been drained and flushed within the past 24 months.

I do not participate.

The brake fluid in my 78 Targa is not "touched" absent brake work being done, conversion to Boxster calipers back a few years ago. I have NO reason to expect to soon address the brake fluid issue at ANY level even for my '01 911/996 C4, therefore NONE of our vehicles are likely to be subject to this type of dealer RIP-OFF

 

Oh,

Hybrid vs "non-hybrid" frictional brake wear...

Just wherefrom do you think that "free" energy comes from that yeilds such "stellar" FE for city stop and go driving for a hybrid vs a vehicle that MUST use the brakes, OFTEN use the brakes, in those very same conditions??

To me it would be foolish (fuelish??) to take the position that the frictional brakes on a hybrid would have the same wear rate/mile as an equivalently driven standard vehicle.

Hybrid braking simultaneously with frictional braking or "transitional"..???

First, wouldn't it be pretty foolish of a hybrid system design engineer to have the frictional brakes always operate in parallel with the regenerative braking system?

And the way I read the information in the shop/repair manuals for our Prius the frictional brakes are NOT used unless the driver depresses the brake pedal far enough that the cognizant level of braking "required" cannot be supplied by the use of regenerative braking alone. Exception being an already FULLY charged hybrid battery.

The information available for some of the the later HSD models indicate that the frictional brake system's brake piston fluid pressure is slightly elevated to bring the pads in (s)light contact with the rotor just as you first, initailly, apply the brakes.

The sudden brake "bump", transition, from regenerative braking to frictional braking might have more to do with road conditions than the management of the two braking methods.

If ABS or VSC were to activate for some reason (pothole, washboard road surface..??) during combined frictional and regenerative braking, or ONLY regenerative braking, it is very likely, HIGHLY likely, that the system would INSTANTLY disable regenerative braking.

And THAT would probably not be a smooth transition.

 

Have you ever read any information on the Escape? The manual clearly states that when you step on the brakes and are decelerating using regen, the rear brakes are applied slightly. This provides four wheel stopping making it feel like a normal car. So, yes, they do in fact operate in parallel (friction and regen).

This is very easily defeated by driving in L in most conditions.

 

And the contribution of the rear brakes to slowing and/or stopping is...

I typically replace my front brake pads 3 to 4 times before I have to replace my rear pads once.

But the real answer, implicitly, only pertains to brake frictional surfaces that can be "saved" from wear via use of regenerative braking. So my responsive post was a bit off point too.

"What" is easily defeated via dring in L...??