HOW TO : Replace Front Brake Pads and Discs (Rotors) Prius Gen 2

Hi George,
This is first time joined in this Prius Owners Club! I have been driving Prius III-2009 and have 100,000 miles on it. Last week I was told from the Dealer while went for an Oil Change to do a front brake pads and resurfacing and would cost me about $300.00.
I have a decent mechanic and he can easily do the job and would cost me so much less.
The question I have: Does he have to unplug the battery from your Steps number 4 & 5. He told me people are faraid of the bolts. Please suggest me, when you get a chance.
I would really appreciated your feedback.
Thanks.

 

Ianini, the thread on the rotor holes (for removal aid), on a third gen at least, is M8x1.25. I'd heard this in a YouTube video, but was sceptical at first: mine were pretty rusty, and the bolts were reluctant to screw in. I just kept running them in as far they'd go easily, then back 'em out and repeat. Eventially went through, all happy, no cross-thread. Then keep screwing them in, a bit on one, then the other, with a ratchet wrench. When the rotor finally popped off, in my case, it was semi-spectacular, kinda noisy.

chaloo, when I did ours, again: 3rd gen, I disconnected negative cable of 12 volt battery, and just for good measure left the driver's door ajar. Then when done, pumped the brake pedal multiple times to build up pressure, then hooked up 12 volt. Had no issues thus.

 

Thanks for the write up, used it today.
I had to remove the lower strut nut to get a good purchase on the upper caliper carrier bolt.
One rotor popped right off but the other needed an extra soaking of PB Blaster and then a propane torch with much rubber mallet persuasion. Did the Neutral barking to bed in the new rotors and pads and all is well.
Thanks again.

 

As others have said, thanks very much for posting this helpful and detailed information!

I was asking a Toyota dealer mechanic about doing the front pads and rotors, and he warned me that the brake system must be "zero-pointed" to relieve all the pressure, otherwise pressing the piston back in could damage the accumulator.

Clearly many of you have done this job, and you are still posting so I'm assuming your brakes haven't failed! Is this just a scare tactic by a dealer mechanic so I'll bring the job to them?

Many thanks!

 

Scar tactic. Many PC members have as I have Techstream the same program the Dealer uses for many service tasks on the Prius "and other Toyota group cars".
Zero point calibration is a power steering calibration required after front wheel alignment.
There is a calibration required on the brakes after a new brake control unit is fitted, but this is a linear solenoid calibration.
Fluid must be able to travel back from the calipers freely after taking your foot off the brakes. If it could not the brakes would remain on.
The important thing to remember when working on Prius brakes is the disconnection of the 12 volt battery even when removing the rear brake drums on the US version of the car, and under no circumstances open a bleed valve unless you have the Techstream system.

John (Britprius)

 

Hi John,

Thanks for the confirmation! One more question, the Toyota tech said that they spray the slide pins with silicone spray, yet I was told by someone else that copper anti-seize compound is better, as it's more heat resistant, and not as thin a lubricant. Which is better to use?

Many thanks!

 

In the Repair Manual Toyota uses a couple of expressions:

1. "Disc brake grease": at points of contact between shims and pad backs (I use anti-seize for this, believe it's what they mean.)

2. "Lithium soap base glycol grease": on caliper pins, and their rubber bushings as well (I used Sil-Glyde for this. It was recommended here, along with a few other similar lubes. It was readily available locally, so I went with it. It has the appearance of Vaseline.)

I would NOT use anti-seize for the pins. Never tried it, by I've heard bad things: it'll dry out, not the stuff to use.

 

These are my front pins when I first took them out, this is the grease that was left on them. This was the grease from the factory. It's very similar in appearance to Sil-Glyde.



Note, they're two different lengths.

 

Okay, so I'm part way through the job, and I'm having a hell of a time getting the new pads into the caliper rails! It's like it's a thousandth of an inch to large!



I can get it in on an angle, but not straight, and certainly not that it would slide!

Is it supposed to like this?

Many thanks!

 

Mendel, thanks for the advice on the Sil-Glyde! It's hard to find in Canada, but I did finally get some.

 

Ah-hah! The rust build-up was the culprit! Wire brushed and filed smooth, and now the pads go in!



It's amazing to me that the rotors just sit on the hub, rather than being bolted on!

 

Brand new rotor?

 

I was going to write up what I had learned about the Toyota greases these refer to, but saw that another member 'agape' already did in this post.



The 08887-01206 so-called "rubber grease" is the lithium soap based grease for metal-to-rubber surfaces: the slide pins, caliper pistons and seals, and boots. It is pinkish and has a sort of musty smell (as others have written, it's not just me). If you buy a Toyota reman caliper and immediately waive your warranty by popping out the piston to see what grease they used, it's pink and smells musty ... it's this stuff.

The other -80409 and -80609 are the metal-to-metal disk brake greases. What I haven't been able to find out yet is whether they are actually different stuff, or just packaged differently ... -80409 in little packets you might use one per brake job, -80609 in a thirty-dollar tube a DIYer probably won't ever use up.

When you buy a shim kit from Toyota, one of those little packets of shim grease comes in it. When you buy the seals-n-boots kit, there's a little packet of the pink rubber grease in it.

-Chap

 

And, as I just learned for myself the other day, everything the manual says about choosing where they sit on the hub is totally serious. A couple years ago I discovered my front rotors had the disease where the inboard side (the one that's hard to see, natch) has wide bands of rust and just a narrow track down the middle where the pads touch. So I got new pads and had the rotors machined, but in reassembly someone was waiting for me so I just stuck the rotors back on any which way and put everything back together.

Since that time, I haven't really noticed brake pulsation, but there has been a woosh-woosh sound and finally this week I thought I'd follow what the manual said, stick a dial indicator out near the rim of the rotor and see what the runout was as I turned the hub. Per spec it's supposed to be no more than .002" but mine were four times that bad, out around .008". Oops!

The magic is what comes next. The manual just says to keep taking the rotor back off and rotating it to the next way the holes line up, and try it again. Considering I started with .008" and there was rust on the hub and rotor and everything was so old, I was skeptical how much improvement it could make, but sure enough, on both sides, I tried all the positions and most were sort of bad, but each side had one position where magically the runout dropped to less than .002". It was so easy I felt kind of sheepish for having skipped that step back when I first had the rotors turned.

-Chap

 

Yes, brand new rotor... not that the rotors needed to be replaced.

Back before the winter, I had the front bearings done, and the Toyota tech told me that my brakes and rotors were at the end of life, and needed to be replaced. He suggested I get the pads and rotors done while he was doing the bearings. I said that I looked at the pads when I put my winter wheels on, and there seemed to be enough pad left for a while.

I planned to do the brakes when I swapped my summer rims back on, so the other day, I went to Toyota and bought the rotors, pads, and shim kit. I find out afterwards that they charge a 20% restocking fee on all items. I just figured 'screw it'... these cars have been good to me, and compared to the Volvo's that we used to drive, the brake parts are cheap.

I didn't use the black lubricant that came with the pads, but instead used the copper anti-seize compound. I applied a thin layer on the back of the pad, in between the shims, and on the back of the outside shim (where it would contact the piston or calliper). I cleaned up the SS clips that the pads slide in, and the rusted calliper body, and then applied some of the Sil-Glyde lubricant to these surfaces.

After everything was reassembled, I replaced the relays, and reconnected the 12v battery. I powered on, and then powered on again, pumped the brakes a few times (although I suspect I didn't have to as the accumulator likely charged the pressure up for me? Does anyone know for sure?), and then drove the car around the neighbourhood testing the brakes. They are wonderfully smooth and quiet. I never took the cap off the brake fluid reservoir, and never had an issue.

It took me over an hour to do the first one, as I couldn't figure out why the new pads wouldn't fit, and about 20 minutes to do the second one. The Toyota tech told me that it takes a couple of hours to replace front rotors and pads. Unless it's his first time too, it seems to me that he should be able to do this job, realistically, in about a half hour, especially considering he has a hoist and isn't bent over the whole time!

Thanks to everyone here and to the OP for the helpful advice! What a great community!

 

I'm a Gen 1 driver and there are a couple notable differences between my car and yours (a main one, my ABS can control the two front wheels independently but the rears only as a pair, yours has all four independent) but one thing I think hasn't changed is that the fronts (and only the fronts) can be operated in two completely independent ways. They do get pressure from the accumulator, if pressure is available, but if it isn't for any reason, they are operated by fluid from a different master cylinder chamber and following a different path through the actuator. If you never opened anything then you didn't have to bleed, but if you happened to look at the bleed instructions in your service manual, if anything like mine there's a puzzling procedure that seems like it might be a mistake because you end up doing the fronts twice, once without accumulator pressure and once with. Then you can stare at the diagrams in the New Car Features Manual for a while until you say "aha! that's not a mistake!"

So maybe you really were meaning to test both circuits even if you didn't realize it.

-Chap

 

Here's an update on my front brake change:

I originally replaced the front pads and rotors on my 2006 Prius on 4/17/14 at 132K miles. Fast forward a year, I now have 176K miles on my Prius and I noticed that periodically when I would brake that my car would slightly pull to one side. Since I didn't use Lithium soap base glycol grease to lube the slide pins, but rather high temp bearing grease, that this could be the cause of the problem. I purchased Qty 4 Bush Dust Boots and a tube of the Toyota brand Lithium soap base glycol grease on eBay.

Today I removed the old Bush Dust Boots, cleaned out the Disk Brake Mounting holes with brake cleaner, and reassembled everything using the correct Lithium soap base glycol grease. Everything seems to be good to go.

Just passing this along, make sure you use the proper Lithium soap base glycol grease on the slide pins, and you won't run into the problem that I did.

Mylar

 

Thanks for the update! I'll be especially curious to know what you think in comparison, after fast-forwarding another year and 44K more miles.

In disassembling today, did you notice one or both calipers not floating freely?

-Chap

 

I didn't pay much attention to the calipers, the slide pins did pull out, but you needed to use some force. When I reassembled everything, I was able to torque the caliper bolts to 25 ft-lbs, something I couldn't do previously because at the time I didn't own a torque wrench.

Braking action appears to have improved. I'll definitely provide an update in another year, assuming I still own this car.

Mylar