TBH I didn't know a caliper could warp.

50,000+ miles since my caliper grind and all is well. I've looked at them oodles of times during ire rotations, seasonal swaps and most recently when changing the rear pads at 58,000 miles.

The only slight negative impact is the tight clearance and the inevitable scratching /grooving of the rims internally from off-road debris. Also a small scratch on the unadulterated front calipers.

No downside to this mod in my limited experience.


Caliper in situ 48,000 miles post shave

 

I’ve yet to hear of a failure also. That does not rule it out, but I feel like I’d have heard yipping given the circles I keep tabs with (other idiots as obsessed with Defenders as I am).

BTW - regarding failure mode of a cast component like this. I bet what would happen is the caliper would seize from improper heat sink/heat cycling/cooling and the pistons would seize in their barrels, and the caliper would thus have failed. Or if someone simply ground off way too much, the metal would fatigue/crack from heat cycles. Obvious failure at that point.

The only P400 rear brake failure I’m aware of firsthand (and Gavin knows what I’m talking about) -- someone we know had a rear brake caliper fail causing a very difficult to diagnose brake fault. Eventually a tech figured out that one of the rear brake calipers was leaking fluid internally into the parking brake actuator that attaches to the caliper- it was maddening to diagnose apparently, as no fluid leak was visible externally. But the car detected the lack of braking pressure, the fluid loss and threw all sorts of fits. This caused a braking issue (obviously) and brake faults all over the dash (from fluid loss/displacement). Fix was to swap out the caliper. Simple.

Notably, this was not on a caliper that had been trimmed. It was on one of the Lucky 8 Caliper swap kits for a P400 rear brake setup -- I believe it’s just a Discovery 5 stock component -- and really -- a bit of bad luck. A faulty component since those Lucky 8 kits are Genuine LR and brand new.

 

Good to know, thanks!

 

Two years ago, 30k miles later and no problems on my grind. If you want to read the details of my effort here's the Link (P400 to 18" Wheel Project - Land Rover Forums - Land Rover Enthusiast Forum). As always, ymmv and I give NO recommendations, warranties, yada yada yada. Do this you are on your own. Me: no probs since I did it.

 

You're going to like the way your calipers and 18" rims look

 

Just wanted to chime in on my DIY:

Have a 2020 P400, chose the caliper swap option.

While there were off, rebuilt the “new calipers” and powder coated them.
FYI, if you swap the caliper ann caliper carrier, it will change the caliper offset and might not clamp the rotor where it should. Ask me how I know…

Anyway, I installed the new calipers and redbourne 18’s.

There is the slightest rubbing on the leading edge of the caliper “knuckles”.
Looks like I’ll still need to grind a bit to get more clearance… pics below.

FYI looks like even after extensive research, Powerful UK also had a 18 rim touch the caliper after a swap of the caliper...

 

Very neat looking work

Yeah PUK were trying to fit the steel rims on their P400. Wont work without spacers due to the +41.5mm offset.

I'm surprised your rims rubbed. I thought the Alstons were one of the ones that works well with the swap. That's a bummer having to shave the calipers after a swap. Hopefully it was before all the pretty red powder coat went on.

 

Sadly no. The powder will need to be done, but at this point at a future point. Need the P400 on the road, so I will just take a file to get a bit of a gap at the leading edge and put some clear coat on it for now. I put 30mm spacers to see about pushing the rim out, thinking it would give more clearance but sadly it just shifted the rubbing to a different location on the inside of the rim.

I too was surprised that it didnt clear, and by at least 1/4"+. In hind sight I wish I had done a dry fit first, pre-powder.

Fortunately since its toward the back of the caliper, it should not be visible, but as you know, that once you know it's there, it's hard to forget.