After its first ever brake job, at about 130,000 miles, “Carmelita” developed this incredibly loud grinding noise on engaging the mechanical brakes when coming to a full stop.The brakes also feel grabby. My mechanic did not believe me, so I recorded it one day and they were totally shocked. They looked at it again and they could not find anything wrong with the brakes. But the dinosaur screech continues. It is loud enough that people on the sidewalk will turn their heads and stare. It is worse after it has been wet. And it seems to get better after a few uses of the brakes on a trip. But then it will crop up on every use of the car. Admittedly the car only gets about 4000 miles a year and only gets used every few days to a week. Any ideas on how to exercise this demon would be gratefully appreciated.
Did the shop do a visual check of the rear-brakes on both sides of the car? It’s possible something on one side has frozen or rusted, but the other side remains good. It may be necessary for the shop to completely disassemble the brakes on both sides (rear brakes) down to the basic components for a bench inspection to finally figure out what’s causing it.
I’m a little confused by the reference to “mechanical” brakes because that vehicle has conventional hydraulic brakes, plus regenerative braking. If the mechanic has verified that there is nothing wrong with the brake components that he installed, then it is very possible that you are merely hearing the effect of rust build-up on the rotors. The clue to this potentially being merely a rotor rust issue is…
Unlikely, but it is possible on some cars for the pads to inadvertently get installed backwards; i.e. rather than the pad friction surface, the the pad’s backing-plate is facing the rotor. That configuration will make a good deal of noise.
I’m presuming OP is referring to normally-configured hydraulic brakes to differentiate from the electric motor’s regenerative braking function.
On the other hand, it does have a mechanically-activated emergency brake, but I’m assuming–and hoping–that the OP isn’t attempting to stop the car with the e-brake.
The brake pads themselves may be part of the issue depending on the brand. You might have your mechanic change just the pads to a different brand… or use Toyota branded pads from the dealer.
I’m not sure but I brought it to them twice to check and they said everything checked out. It’s now 6 months, about to bring in for regular service, can ask again.
This is what my mechanic thinks. Makes sense… Do I have to live with this forever after because there was rust from early on after the brake job, when the car first sat for a few days to a week? The sound scares pedestrians and dogs will startle.
this generation of Prius uses drum brakes in the rear
from my experience with 2005 year model, by 120k miles it had tons and tons of friction material dust mixed with rust accumulated when I opened it up for inspection (immediately transitioned into “cleanup and lubricate”), I also had some screeching sound from the rear after rain and letting car sit for loo long. no parts were required as it was healthy thickness left on the pads and drum was in good shape
This makes sense to me. Yes, drums in rear. I can ask my mechanic to clean them but I would have thought with them knowing the noise coming from rear they would have looked at this already? I will ask them again.
