Explanation of Brake System

[Optimus]

I've driven my new used 2002 Prius just long enough to know it doesn't have standard vacuum assisted power brakes like "normal" cars do. The brake system is VERY sensative (in a good way for the most part) and is taking a little bit to get used to. But there seems to be 2 components to it, based on pedal feel. The first wee bit of pedal travel has barely any resistance and seems to be an electronic braking, and harder braking seems to be standard hydraulic? I've read discussions of the brake system on the G2's, but it doesn't necessarily apply to the G1's.

I wouldn't say there's a problem with the brakes. They are just, well, different.

[Patrick Wong]

See attached three files.

May I suggest that you subscribe to techinfo.toyota.com and download the 2001 New Car Features Manual. This will provide substantial "theory of operations" content not found in the Toyota repair manual.

[Bobwho]

I wish that I had the time to read this thread before my dealer told me that I had manual adjust drum brakes. I told him that I did not believe him and almost had to fight my way out of the shop. I have not been back to that dealer since then and have used the auto adjusters to remedy the "trouble" myself without having to pay for service to adjust my brakes. The nut even sent me a letter claiming that the auto adjusters would not hold!

[hobbit]

I offered proof on how the auto-adjusters work. Keeping the
parts clean will probably help over the long term; if the
threaded parts rusted they could conceivably stop turning any
more and thus be unable to adapt to shoe wear, but if that was
a really common occurrence we probably wouldn't have this sort
of design in so many cars now.
.
_H*

[DickInBerkeley]

Originally Posted by Patrick Wong

See attached three files.

May I suggest that you subscribe to techinfo.toyota.com and download the 2001 New Car Features Manual. This will provide substantial "theory of operations" content not found in the Toyota repair manual.

Hola Patrick, can you direct me to a site (Chiltons like) where I can find the wear limits for 2001 Prius rotors?

[bwilson4web]

Originally Posted by Optimus

. . .
I wouldn't say there's a problem with the brakes. They are just, well, different.

My wife and I rented a 2001 Prius for three days in 2001 and I noticed the brakes:

• normal operation above 5 mph - we could not detect a change
• just before stop, a quick increase in drag - just before coming to a complete stop, the brakes seemed to 'grab' but not in an abrupt way ... just a way we could notice

After 70,000 miles, I can't even detect it. But even after buying the 2003, NHW11, I couldn't really feel it in the 49,000 mile, used Prius. Otherwise, everything is normal.

Bob Wilson

[Patrick Wong]

Originally Posted by DickInBerkeley

Hola Patrick, can you direct me to a site (Chiltons like) where I can find the wear limits for 2001 Prius rotors?

Hi Dick,

techinfo.toyota.com is Toyota's subscription website to obtain repair manual info.

When I sold my 2001 I also sold my repair manuals for that car. However, the North America 2G front disc rotor when new should be 22 mm thick. Minimum thickness is 20 mm. Classic is probably the same but I don't know for sure.

[Shubin Andrey]

FRONT BRAKE
Front brake pad thickness STD 11.0 mm (0.433 in.)
Front brake pad thickness Minimum 1.0 mm (0.039 in.)
Front brake disc thickness STD 22.0 mm (0.984 in.)
Front brake disc thickness Minimum 20.0 mm (0.906 in.)
Front brake disc runout Maximum 0.05 mm (0.0020 in.)

[z02prius]

Say I have a leak near the Brake Booster when my Gen I is parked over night or at work during the day. Car stop fine no leaks during driving. Any idea I can not see were the fluid is coming from. I use a bottle a week.

[bwilson4web]

Originally Posted by z02prius

Say I have a leak near the Brake Booster when my Gen I is parked over night or at work during the day. Car stop fine no leaks during driving. Any idea I can not see were the fluid is coming from. I use a bottle a week.

If you are lucky, there is a loose connector. If not, one of the brake lines is failing. Regardless, it is probably time to have a brake shop take a look at it unless you're willing to 'dig in' to the area and find the fault.

Bob Wilson