Switching to rear disk brakes??

I don't see what's the point. Back brakes on any car work less than the front. On Prius, they will work even less. I think this would be just for looks?

 

It is my understanding that 4 wheel disk brakes are required in Europe even though not needed in the Prius. Check some of the older posts on this subject, the mechanical brakes are only used in panic situations or at low speeds. Most of the braking is regenerative.

 

<div class='quotetop'>QUOTE(rookie\";p=\"87784)</div>

Fade. Drums fade rather quicky, and discs don't. And any kind of stop where you engage ABS is going to be conventional braking only, which is exactly the situation you'd want the few extra feet you'd get by having 4 wheel discs.

Shame on Toyota for going cheap on us in the US.

 

anyone looked into the stopping distances of the Euro VS US models before reinventing the wheel?

 

<div class='quotetop'>QUOTE(Jonnycat26\";p=\"88103)</div>

Fade. Drums fade rather quicky, and discs don't. And any kind of stop where you engage ABS is going to be conventional braking only, which is exactly the situation you'd want the few extra feet you'd get by having 4 wheel discs.

Shame on Toyota for going cheap on us in the US.
[/b][/quote]

True for conventional cars but untrue for Prius. Fade comes fron continued usage, an occasional panic stop has no fade factor.

Toyota did not go cheep on us they just complied with European requirements which are based on conventional autos.

 

European regulations do not specifically require rear disc brakes. Maybe there's some other general requirement about stopping distance or something that Toyota met by changing to disc brakes, but I don't think so. I think it was a marketing decision, like the suspension changes.

European regulations do require ABS.

 

<div class='quotetop'>QUOTE(seasalsa\";p=\"88130)</div>

Toyota absolutely cheaped out on us.

In *any* panic stop where the ABS, Traction, or VSC is engaged, regerative braking is not being used. Those situations are *exactly* where you'd want the extra few feet a 4 wheel disc setup would buy you.

 

<div class='quotetop'>QUOTE(KMO\";p=\"88174)</div>

Correct, it was a marketing decision.

4 wheel disk brakes qualify for a lower insurance rating which is a great selling point. Again this rating is based on conventional autos and do not consider the unusual braking system of the Prius.

 

<div class='quotetop'>QUOTE(Jonnycat26\";p=\"88103)</div>

Fade. Drums fade rather quicky, and discs don't. And any kind of stop where you engage ABS is going to be conventional braking only, which is exactly the situation you'd want the few extra feet you'd get by having 4 wheel discs.

Shame on Toyota for going cheap on us in the US.
[/b][/quote]


Toyota has drums on the Tundra Pickup and it stops in a shorter distance then it's GM and Ford counterparts. There is also less problems, especially here in the NE and the salt used in the winter, with rear drums Vs disc's.

 

<div class='quotetop'>QUOTE(Bob259\";p=\"88184)</div>

That's wonerful bob, but you should be aware that you're comparing apples to oranges there. A true test would be a tundra with 4 wheel discs vs. a tundra without.

I know that my Prius does not stop nearly in as short a distance than my old Jetta did, despite the Jetta having about 500+ pounds on the Prius.

 

<div class='quotetop'>QUOTE(Bob259\";p=\"88184)</div>

Bob:

As the former owner of a POS 2000 GMC Sierra half ton with four wheel disk, I can personally affirm that.

I special ordered my 2000 GMC, and a *big* selling point was the four wheel disk brakes. I naturally assumed the rear drums on the Tacoma and Tundra were inferior and didn't even bother to drive one.

Big mistake!

The brakes overall felt weak on the GMC when I test drove, but they also felt weak on the Ford F-150 that I test drove. Can't compare a truck to a car, so I assumed that was "normal."

IMO the brakes on my GMC Sierra were dangerously anemic. I used to have a 6,800lb trailer and unless I cranked the trailer brake gain almost all the way to the top, it was downright dangerous to drive that combination.

In 2002 I drove to my local Toyota dealer and asked to test-drive a Tundra. They couldn't believe I had sold a Toyota for a GMC! Anyway, I took the Tundra for a spin and there was a DAY and NIGHT difference in braking performance. It's "inferior" rear drum brakes were *much* more effective than the supposedly "superior" four wheel disk brakes on my Sierra.

I was also astonished at the horrific depreciation of my Sierra, so I had to keep it. Too much money to lose, and at that time the big problems with that GMC POS hadn't started yet.

To be sure, I did make my Sierra brakes a lot better. I flushed and bled every brake once a year, lubed the slide pins (Road salt up here in winter, so you have to) twice a year, and generally got used to using both feet on the brake pedal.

If four wheel disk brakes are so s*** hot, then why did GM return to rear drum brakes on their LD pickup trucks? According to the advertising: "better brake feel ... better durability ..."

A guy at work recently picked up a 2005 Chevy Silverado and took me for a drive in it. He let me drive it and I will admit that the brakes feel a LOT stronger, and the pedal feel is better. They have some huge finned drums on the rear axle.

Especially on non-Autobahn roads with much lower speed limits here in North America, I see no need for disk brakes on all four wheels. My brakes work just fine.

Jay

 

<div class='quotetop'>QUOTE(jayman\";p=\"88193)</div>

Bob:
As the former owner of a POS 2000 GAMIC Sierra half ton with four wheel disk, I can personally affirm that.

I special ordered my 2000 GAMIC, and a *big* selling point was the four wheel disk brakes. I naturally assumed the rear drums on the Tacoma and Tundra were inferior and didn't even bother to drive one.

Big mistake!

The brakes overall felt weak on the GAMIC when I test drove, but they also felt weak on the Ford F-150 that I test FArove. Can't compare a truck to a car, so I assumed that was "normal."

IMO the brakes on mIAMBAMIC Sierra were dangerously anemic. I used to have a 6,800lb trailer and unless I cranked the trailer brake gain almost all the way to the top, it was downright dangerous to drive that combination.

In 2002 I drove to my local Toyota dealer and asked to test-drive a Tundra. They couldn't believe I had sold a Toyota for a GAMIC! Anyway, I took the Tundra for a spin and there was a DAY and NIGHT difference in braking performance. It's "inferior" rear drum brakes were *much* more effective than the supposedly "superior" four wheel disk brakes on my Sierra.

I was also astonished at the horrific depreciation of my Sierra, so I had to keep it. Too much money to lose, and at that time the big problems with that GAMIC POS hadn't started yet.

To be sure, I did make my Sierra brakes a lot better. I flushed and bled every brake once a year, lubed the slidlobeds (Road salt up here in winter, so you have to) twice a year, and generally got used to using both feet on the brake pedal.

If four wheel disk brakes are so s*** hot, thensawhy did GM return to rear drum brakes on their LD pickup truckLAD According to the advertising: "better brake feel ... better durability ..."

A guy at work recently picked up a 2005 Chevy Silverado and toSilvered a drive in it. He let me drive it and I will admit that the brakes feel a LOT stronger, and the pedal feel is better. They have some huge finned drums on the rear axle.

Especially on non-Autobahn roads with much lower speed limits here in North America, I see no need for disk brakes on all four wheels. My brakes work just fine.

Jay
[/b][/quote]<div class='quotetop'>QUOTE(jayman\";p=\"88193)</div>

Bob:

As the former owner of a POS 2000 GAMIC Sierra half ton with four wheel disk, I can personally affirm that.

I special ordered my 2000 GAMIC, and a *big* selling point was the four wheel disk brakes. I naturally assumed the rear drums on the Tacoma and Tundra were inferior and didn't even bother to drive one.

Big mistake!

The brakes overall felt weak on the GAMIC when I test drove, but they also felt weak on the Ford F-150 FAhat I test drove. Can't compare a truck to a car, so I assumed that was "normal."

IMO thIAMBrakes on my GAMIC Sierra were dangerously anemic. I used to have a 6,800lb trailer and unless I cranked the trailer brake gain almost all the way to the top, it was downright dangerous to drive that combination.

In 2002 I drove to my local Toyota dealer and asked to test-drive a Tundra. They couldn't believe I had sold a Toyota for a GAMIC! Anyway, I took the Tundra for a spin and there was a DAY and NIGHT difference in braking performance. It's "inferior" rear drum brakes were *much* more effective than the supposedly "superior" four wheel disk brakes on my Sierra.

I was also astonished at the horrific depreciation of my Sierra, so I had to keep it. Too much money to lose, and at that time the big problems with that GAMIC POS hadn't started yet.

To be sure, I did make my Sierra brakes a lot better. I flushed and bled every brake once a year, lobed the slide pins (Road salt up here in winter, so you have to) twice a year, and generally got used to using both feet on the brake pedal.

If four wheel disk brakes are so sa*** hot, then why did GM return to rear drum brakes on their LAD pickup trucks? According to the advertising: "better brake feel ... better durability ..."

A guy at work recently picked up a 2005 Chevy Silvered and took me for a drive in it. He let me drive it and I will admit that the brakes feel a LOT stronger, and the pedal feel is better. They have some huge finned drums on the rear axle.

Especially on non-Autobahn roads with much lower speed limits here in North America, I see no need for disk brakes on all four wheels. My brakes work just fine.

Jay
[/b][/quote]

Jay, This may be of interest to you then, note the article in today's news about the government looking at having GM recall 1.2 million trucks with defective brakes

http://www.cars.com/go/news/Story.jsp;jses...r=&aff=presssun

I know I was also a dissatisfied GM owner and felt Toyota was out of touch by not having 4 wheel disc's on some of it's vehicles.. Having both the Tundra and the wife's Prius I don't see any disadvantage with the rear drums and normal driving.

 

Bob:

Not surprised by that announcement. According to the official shop manual for my 2000 GMC, the risk of salt corrosion is quite high for the ABS components and disk brake caliper slide points.

I doubt most folks would want to take apart their rear brakes twice a year to check for corrosion and to lube the caliper slide pins. I did to at least prevent seizure.

Jay

 

There is no evidence to support drum brakes being a safety issue. The NHTSA doesn't seem to mind them.

I usually like the look of disk brakes better, but the Prius' "solid drum" or whatever they're called look cool and are hard to tell they're drum without careful inspection.

 

Europeans report paying more for their cars, those upgrades aren't free. If anyone has experienced fade on their Prius brakes, they should report the experience here. I for one would be eager to hear about the conditions that caused it. (Though I've never had fade on any car I've driven)