Brake clunking when braking

Very Common with Gen2 Prius... Pretty sure you can grease the pins to prevent it... But it's just noise. Never read that it could cause a mechanical failure.

 

Diagnosis cannot be made from here. But at the top of my list of things that I suspect is Chinese brake pads that are glued to the backing plate and became separated from heat

 

Probably the calliper mounting pins, which position the callipers while allowing them to shift laterally. Read up on this stuff, and there’s specific lubrication specs; just using what you have on hand can backfire.

 

FWIW on caliper pins I’ve been using Sil-Glyde Brake Lubricant. And for pad to shim to caliper contact points: Permatex Anti-Seize.

 

The caliper pins? Take a look at first attachment in post #4. Toyota calls them “cylinder slide pin”.

 

Not likely and I would not use spray on grease. You need to remove the slide pins and may need to clean out the old grease. You then need to re-lube the slide pins with the correct lithium soap base glycol grease. Toyota recommends their rubber grease Part# 08887–01206 which is pretty cheap ($8 last time I looked)** for a 100g tube that will last ages.


EDIT ** I just looked it up and it is now $11.35 Still cheap.

 

Have a look at the “rear brake” link in my signature (on a phone turn it landscape to see signature). It’s specific to 3rd gen rear issue, but there’s some general and Prius-specific tips, in particular a 12 volt disconnect strategy. And have a read through the attachments in post 4.

 

That's where you get Chinese junk. The backing plates are glued to the pad. They separate when they get hot. You're risking your life. Avoid that store.

DOT does not investigate cause of crashes from passenger automobiles. They only investigate commercial vehicles. They measure the brake linings. The tread thickness, the suspension, the play in the steering etc. They put the truck on a concrete pad and they walk under the vehicle to get on the stairs and they dismantle the truck after the accident. Imagine if they did that with passenger cars? I suspect there is a plethora of fatalities from Chinese parts that is yet to be discovered by the American public

 

Probably not easy to find the Toyota rubber grease there anyway.