What did the Dealership do to My Car?

they would have felt a bad cv joint during the test. if it is, you will soon be hearing a sound.

 

It's always preferable to have corroboration: maybe check the rear brakes for yourself.

The supplied scissor jack will get one corner at a time up. You can pick up a pair of cheap but effective tire chocks for under $10 (keep them in the car, for use changing a flat): chock the front tire diagonally across from the rear wheel you're going to raise.

8-1/4 x 4 in. Wheel Chock Set | Princess Auto

 

Hey Tony,
I know they say that the wheels are spinning freely (and they probably are) but, that doesn't mean there's not more drag from the new brakes. The only real way to confirm this is you would have to have known the drag on the old brakes (measured) and compare it to the drag on the new brakes (measured). The only measurement we have is fuel economy and that clearly indicates more drag. It is very common that new brakes will temporarily apply increased drag on the rotors and shoes/hub. This is just a fact of life. How much it will induce will vary but you seem to have a lot. If it were me, I would run the car as is for about 2 weeks and see if the fuel economy improves. If it doesn't, I would suspect a wheel bearing and then go from there (wheel bearings will typically make noise (humm) when they are getting ready to go). I'm betting time and driving will fix this problem (it will wear down the pads, rotors, shoes and hubs and slowly decrease drag).

 

Yeah, if it hasn't improved by now, it may never. I would begin to suspect wheel bearings (especially since its an '04) but, only 100,000, its hard to say. I know my '01 rear wheel bearing did begin to hum at 96,000.

 

Another slight possibility - given that there was noise which went away when the wheels were changed back round - might be to check the balance on the wheels and the tracking. if the tow in has increased it might make things feel strange and reduce economy, also look for uneven tire wear

 

tony, looking at your mileage chart, i see that your last tank started to come back up. and looking at last summer (2011) you also had some lower tanks. i wonder how much of an anomoly this really is?

 

B-mode engaged somehow?

 

No, if it was B mode, he wouldn't even come close to 60 mpg's.

 

You haven't mentioned any change in the steering, but I would suspect wheel alignment (and wheel balance while you're down there). Not as the only cause, but as a contributing factor.
Rotating tyres on a FWD must be done regularly (every 10000km/6000miles) or never. Once the wear patterns start to differ front to rear too greatly, rotating the tyres will sound like the wheel bearings have been replaced by pop-rocks. As you've found.
When you get a wheel alignment and wheel balance, ask them to check how far off optimum the numbers were. Neither should have been affected by the service, even though there was a lot of service action down there, so there's no suggestion that the dealer did anything wrong.

 

New brake pads will cause more drag when they are new. It takes a while for them to wear a bit, especially on a Prius, for this to go away.

Also, it is possible that the rear shoes were adjusted a bit too tight. How many clicks does it take for you to fully engage the E-brake? If it is 5-7 clicks, then that is about right.


iPhone ?

 

No! Don't rotate them back! If it has been more than 10000km/6000 miles, the difference in wear may be too great. You'll notice the noise immediately, as you did. In fact, that's probably the best test to determine if you can rotate. Leave the tyres in their current positions as replace them as a set. 50000 miles (80000km) is a reasonable distance for LRR or similar tyres.
I align and balance my wheels regularly, even if I haven't slammed into a kerb or driven off-road. I'm not suggesting that this explains the fuel consumption (slight thread hijack), but it's a cheap fix and can solve otherwise hidden problems.

The Critic is right about new brake pads. By necessity, they are close to the rotors when new. Unlike drum brake shoes, there's no spring to return disc brake pads to a home position, so the pads may rub a little until the pistons "relax". New pads self-adjust and bed-in, but these processes take much longer in a car when the pads don't touch the rotors until the car is moving slowly.
I suggest you find a quiet straight road and do a few hard stops so that the pads touch the rotors from 80km/h (50mph) or so. That is, brake like you've never ever braked in a Prius. You could discover a few things from this:

• does the car stop straight or did I have to wrestle it?
• does the steering wheel shudder?
• does the car dip alarmingly?
• how does it feel when the car is at maximum braking, so when I have to do this for real I don't freak out and release the brake pedal (thereby nullifying braking that the ABS had under control) because of some distant memory of Driver's Ed?

 

When doing Braddles suggestion Tony, put the car in neutral while applying brakes so you are not using the regeneration braking. Doing this from moderate stops should center and break-in the front pads.

 

In the UK we we get tired, but we buy tyres for our cars.

 

Thanks for the update, Tony. I feel further justified in never rotating my tyres :_>

Why did the brake rotors need turning?