Seized rear calipers - Rivian stuck me with the bill

[Killer95Stang]

Interesting thread!!
I agree (for the most part) that wear items are an expense with any vehicle you own. I am more curious though as to what the costs of "maintenance" would be for some of these vehicles after 4, 5 or more years or once the factory warranty has expired. As an owner of several German vehicles, I know the "pain" that this carries ($$$).
Another question is: Will the service centers be prepared to deal with the increased "demand" when this happens??? Just one of many reasons why I chose to lease, rather than "buy".
Oh yeah....and NO, no news on my car yet........waiting to hear from the Portland SC......

I always said that about a BMW. Either lease or never own one out of warranty!!. Then I went and bought a Rivian...

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[Wing]

My rear rotors are somewhat corroded. Brought this up to the tech, said it's because they don't get used much.

As someone who does all work on my vehicles myself, I know this to be mostly true.

My wife's brand new CRV needed to rear pads/rotors at 38k (JUST out of warranty) due to stuck calipers. That's what living in New England gets you. Plus the brake proportioning valve doesn't give as much pressure to the rears (by design) under heavy braking, so they just don't get used much.

When it's time, I'll just replace the pads/rotors myself. It's a 15 minute job per side. Just hope there is a way to release the parking brake in the software so I can manually retract the piston.

You can use neutral but that is a 15 min timer. But honestly should be enough time...

 

[IGR]

My rear rotors are somewhat corroded. Brought this up to the tech, said it's because they don't get used much.

As someone who does all work on my vehicles myself, I know this to be mostly true.

My wife's brand new CRV needed to rear pads/rotors at 38k (JUST out of warranty) due to stuck calipers. That's what living in New England gets you. Plus the brake proportioning valve doesn't give as much pressure to the rears (by design) under heavy braking, so they just don't get used much.

When it's time, I'll just replace the pads/rotors myself. It's a 15 minute job per side. Just hope there is a way to release the parking brake in the software so I can manually retract the piston.

You can use neutral but that is a 15 min timer. But honestly should be enough time...

Well look at that, its a 15 min job, and Rivian's parking release will time out in 15 minutes, queue the Mission Impossible theme music...

 

[Killer95Stang]

Well look at that, its a 15 min job, and Rivian's parking release will time out in 15 minutes, queue the Mission Impossible theme music...

Instead of the bomb going off, a caliper piston shoots across the room...

 

[Wing]

Yeah you can just jam the pads back in I would think worse case.

It somewhat annoys me they don't provide a way to disable it in software.

But really you can be prepared and read before hitting the button. Not sure if you can hit it again before the timer runs out.

 

[Riviot]

I always said that about a BMW. Either lease or never own one out of warranty!!. Then I went and bought a Rivian...

I went BMW-BMW-Land Rover-Rivian ??

You can use neutral but that is a 15 min timer. But honestly should be enough time...

Stupid question: if you don't have it up on a lift, how do you prevent it from rolling away?

 

[Wing]

Wheel chock? A brick, anything really.

 

[Riviaenz]

Thanks for sharing.

It’s going to be an interesting transition as Rivian stops replacing some of this stuff under warranty. Mine is in the shop today to replace the rear dampers, and they haven’t yet been able to tell me why they need to be replaced, but they’re covering it. Concerned it would be pretty expensive if it wasn’t, and it’s similar to yours, early 22 with 35k miles. Manufacturing issue? Normal wear and tear? Hoping I get to an answer…. But bummer you’re on the hook for the brake pads, which most EVs don’t need to replace for a while.

Only this isn’t a warranty issue. Not only are brakes wear items, the rear pads wearing more are typical of adaptive cruise control, auto brake, and brake hold (rear pads are used more for smoother application and ride quality but will cause faster than normal wear given they’re smaller than fronts and are applied more regularly). I’d noticed the same issue on our Volvo XC90 T8 and on Volvo forums it was a common complaint for the first couple of years of them introducing the redesigned XC90 with ADAS features. At 53k I replaced the rear pads. At 64k I replaced the fronts. On that car the front and rear had floating calipers and inside pads were more worn than the outside. The guide pins being lubed is helpful in allowing the caliper to distribute piston force to the outside pads as the inner pads are pushed against the rotor by the pistons.

With regard to the inner pads wearing on the rear, the guide pins need to remain lubed/greased to more evenly distribute the brake force between the inner and outer pads. The pistons are on the inside of those calipers. The front calipers don’t have that issue, they’re not floating, and instead have pistons on both the inside and outside of the calipers. Related, it sounds like the e-brake/brake hold function is has an electronic actuator/motor on the rears. Seems like that’s been the trend with electric e-brakes (no longer cable actuated hand e-brake) and it does lead to faster rear brake wear.

It would be cool if Rivian allowed for deactivating brake hold. On other cars brake hold can be de-activated to prolong rear pad life.

Something else that could help prolong rear brake life is disabling regen brake assist (new feature they added with the October 2023 update) that provides for consistent braking simulating regen if thermals are not able to sustain the same level of regen - like on long downhills. That would definitely add excessive wear and my other concern is how they’d manage brake fade on long downhills. Two reasons I keep that feature off. I want to know how/when my brakes are being applied and I want to have a good feel for potential brake fade should it become an issue (mountain driving).

 

[Mike Hunt]

I remember the last update or two that they switched their regen/braking strategy to applying breaks to slow down on hills and such when regen failed due to whatever reason.

I have encountered this switch when trying to apply breaks when the truck is applying breaks in place of regen.

I found the break pedal already pressed itself to the max and I had to press even harder to stop the truck.

I wonder if the side effect of this new regen strategy is now premature break wear.

 

[Riviot]

Wheel chock? A brick, anything really.

My last chock didn't stand a chance...

 

[CrazyOne]

Even on ICE cars rear break pads see very little wear.
OP, have you done any off-roading?

There is rear bias to prevent brake dive on a lot of vehicles. I know that some Mazda and Honda vehicles eat rear brakes before the front ones, if you drive conservatively. I have heard that ACC causes some of this.

 

[Nix]

I give kudo's to the mechanic. The reality is that nobody can tell you exactly why your specific brake pads wore out. Brakes aren't just used for braking anymore, and he could have listed off a dozen reasons why yours wore out in this number of miles, but he can't tell you which one. It is impossible to tell.

Some of those reasons can be due to driver's habits, or environmental reasons that have nothing to do with a "Manufacturer's Defect". But as a mechanic, never ever give customers a long list of possible causes where some may involve driver's habits.

The only thing customers will remember is the one item on the list that offends them the most, and become irate that the mechanic dare accuse them of something like leaving the vehicle parked for abnormally long times in salty sea air without driving it, or lots of traction events triggering traction control brake application. The customer won't care that you are only giving them a laundry list of possibilities, they just jump in with "I NEVER's" and nothing good can come from it.


The decision to replace rotors is half art, half science. Replacing an already out-of spec rotor is obvious. But what you really want to do is make sure the rotors will last through the entire lifetime of the new pads. Otherwise you are doing rotors half way through the life of the pads. And doing pads again. Now the customer is mad they just did pads 20K miles ago, and why do they have to pay for the same work twice?

But who can predict exactly how long a rotor will last before it is out of spec? If there has been a known premature wear issue on one side a the rotor of unknown cause, the conservative answer is to replace the rotors.


The reality is that there is only one part of the caliper that is physically powered by the brakes being applied. That's the piston. It applies force directly to the inside brake pad only. The outside pad only reacts indirectly to the piston applying the inside brake pad pressure. That is through the slider. If the lube is gone, the sliders may not do their job sliding. Also if the lube is gone from the edges of the inside pads, they may not retract when the piston retracts and rub even after the brakes are no longer applied.

How long it takes for the lube to go away depends on each owner's environment. Normal conditions the lube may last until the pads wear out. Or in odd conditions like exposure to corrrosives the lube may all be gone after a single event with corrosion starting overnight.

The brake pads actually DID wear evenly, just not in the way you think. 8mm on both outside pads, 2mm on both inside pads. If there was a "Manufacturer's Defect" in one of the calipers, the pads would have had different wear rates on the left side vs. the right side. The chances of both individual calipers having the same "Manufacturer's Defect" on both sides, and the defect causing the same problem on both sides is very low. When there is actually a manufacturer's defect in a brake caliper, it is one wheel at a time (aside from freak chaos theory events).

This wear came from the application of the brakes evenly on both sides of the truck, which points to brake "Wear and Tear" due to the application of the brakes. I can already hear the objection, "If you can't tell me exactly the ONE reason why this happened from the list of a dozen possible reasons why environment and driving habits could affect wear, then it must be because of a manufacture's defect."

Which puts us right back at at the top of my post where I gave the mechanic kudo's for leaving it with just the explanation he gave....

 

[stumptown85]

Yes, I'm paying for labor and pads on a vehicle that mostly stops without the aid of brakes after 35k miles.

So, that is not entirely true anymore. I noticed squeaking on my R1S when on a long gradual downhill stretch. I called to ask why since so far as I knew it was exclusively using regen. Not so much. Apparently when you regen for long enough or hard enough, the breaks engage in their own. I suspect this was a change made to reduce how often regen gets dialed back which used to happen all the time for me and basically never happens anymore. I confirmed with service that brakes are engaging on regen without the brake pedal being used and even if gradual speed reduction situations. This was never disclosed to my knowledge, regen just got better after an update and no one questioned it. This might be why emergency braking is seeing excessive wear.

 

[Hopper]

They fixed it, just refused to pay for a regular maintenance item. Granted, it occurred earlier than many EV drivers estimate.

This may just be an early production issue, we won't know till some newer builds get up in miles with us. I'm a March 2022 delivery with 48k, noticed inners wearing unevenly about 2k ago at seasonal switch, but there's enough to keep it going passed 50k, which is when I budgeted replacement.

March ‘22 with 47k. My truck is at the Trenton SC now for the tonneau update and a comprehensive inspection. We’ll see what they say in 3-5 days when they get around to looking at it.

 

[Trandall]

@JoulesVerne, my rear pads were down to the indicator bar as well at ~50K miles so I had them replace them when it was in for powered tonneau replacement. They did the front pads too just for good measure. They wanted to do the rotors but I declined. I don't think this is going to be an atypical occurrence with the R1's. I had originally thought brake pads would last >100K on any EV with good regen but now I understand it's just not the case. So I'm planning on replacing all pads and rotors, greasing the slider pins and pistons again by 100K miles. Hopefully by that time Rivian will have brake service mode in the software to release the calipers.

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