FWD to larger AWD rotors

[dabangsta]

At around 87,000 miles on my 2019 FWD SEL, and the rear pads are getting pretty thin. I have not had a car in recent memory that I didn't do some sort of big brake upgrade to (10.8 inch to 13 inch Cobra on my Mark VIII, 14 inch GT500 on my Grand Marquis, etc).

 

Mine is FWD and has the smaller front rotors (316mm), and I want to go with the 345mm AWD ones (not looking to go with the ST Base or PP). I will leave the rears the standard 316mm solid.

 

It seems like the caliper is the same for either rotor (and pads), just the bracket/support/mount is different. Can I just go with new caliper mounts, rotors, and pads from the AWD? Or do I need the bracket and caliper? If I put in the VIN for my FWD and for an AWD vehicle, I get same PN for calipers, different for rotors and brackets(supports), so not sure. Also they are referenced as "front vented 17" and 18 front vented. I assume that is for older years that still had 17 inch wheels standard (but all 2015+ have 18+ wheels).

 

If I can get away with not unhooking the calipers so I need to bleed them, all the better. I am going to guess that it won't affect anything like ABS, stop and go cruise, collision avoidance, etc. I have a 17 inch spare, I think I have seen recent posts about 17 inch spare fitting over front and rear ST brakes, which have same rotor size but caliper is different.

[dabangsta]

I haven't checked the thickness of the rotors, but I haven't had rotors turned in a long time, and I don't plan on pad slapping this one either, so $100 for the caliper brackets, and slightly higher for the bigger rotors but not major.

[dabangsta]

So this will finally happen! I am still waiting for the front caliper brackets to match the larger rotors, but Saturday is the day I hope! These front rotors are beefy. It is a daily driver for my wife, and it also gets about 20,000 miles a year, so I didn't go with drilled and slotted, or aggressive pads. I do drive it from time to time so I will appreciate the larger front brakes I hope. I don't really need the coated rotors either, I live in the desert and rust is not really an issue, but for the cost difference, I went with them. I do have pretty good luck with Power Stop brake parts, so I hope that continues.

 

$453 after shipping, $388 after $65 rebate. It is actually cheaper than the above screen shot since they have the same components in a kit, and I added slide pins and boots, and still cheaper. Shipping was $53 because it came from 2 different places, that 5% off discount of $20 didn't cover the shipping like it usually does. Still $100 cheaper than I can get it locally, with the $35 in shipping for the rotors (the shipping for the brackets is $15).

The 2 sizes of Hex key/sockets that no set ever has? 7mm and 11mm, so got those:

The FedEx guy hates me, 160 pounds of boxes!

Why 160 pounds? Well, doing the brakes on my daughters 2015 Fusion as well, at 105,000 miles the rear pads are at 2mm, fronts have enough, but she does a lot of mountain pass driving and cooks them. A little meat on the pads will help with that a bit. I also had to do the normal RockAuto shuffle of adding and removing stuff to get the shipping costs down. It was actually cheaper to order the transmission fluid and air and cabin filters, it knocked $45 off the cost of shipping (adding $38 in parts that will be used, not just tossed in randomly). So her brakes all around will be $200 after rebate. She got quoted $550 for the rear only.

[dabangsta]

I forgot to wait for the 18 inch spare to arrive, but if I have a flat on the front the next 2 days, I will put the spare on the back (which I would likely do with a FWD vehicle anyways). Work is done, 5 hours, because I have no power tools, no lift, and ADHD so I scrubbed and details the back of the rims, the suspension, the brakes, the chassis, etc. It was the little things that kicked my butt. Replacing the rear caliper boots and slides, with the lower having the hard plastic, was a PITA.

 

I didn't pay enough attention to the FWD being rear vented, and AWD being front vented. I didn't change the brake backing pad.

 

The magic that makes it happen, left is the FWD caliper bracket, right is the AWD bracket:

The different rotors:

 

There was way more rust than I am used to, with a CA and AZ car. but still pretty easy to work on.

The money shot:

 

No chance the 17 inch spare will fit

 

The real reason I dug into the brakes. Rear had 2-3mm left. It was starting to shake on normal braking, not just emergency or heavy braking coming down a mountain pass.

 

Fronts has a ton of life left, but I couldn't see just doing the rear, and I wanted the larger brakes

 

So far just drove it enough to sorta bed in the brakes. These are already burnt in (they smelled like I rode them down a mountain pass, still in the box), I didn't do any emergency braking, I did test out adaptive cruise but not the stop part of it.

 

Just staring to wear through the coating

 

A tool I used on a 2000 Ford Expedition, where the rotor hat is the same exact size as the hub, and the rust weld themselves together. Why beat the crap out of something when you can use leverage. This temporary tool had been used on quite a few rusted on rotors and works like a champ. As a temporary one use tool I didn't do enough to it, I need to get rid of the first 3 or 4 rows of threads because the end gets boogered up, but easy enough to clean up.

[johnmarkp]

Great write up.  Thanks for sharing.  I look forward to hearing how you like the setup after they are completely broken in.  I need to do the brakes on my ST soon.

[dolsen]

Im glad to see all this worked out for you. I used to be big on making my cars go faster, now I am at least as committed to making them stop faster too.

 

I also like that you used that bolt to get the rotors off. It gets tiring hitting them with a sledge

[PrinzII]

You just answered a prayer of mine for bigger brakes.  I may be rebudgeting according to what's here (including the 7mm and 11 mm sockets).

But before I plunk down the coin, can you let me know if the braking performance has improved over the stock FWD rotors? With me considering an upgrade to 20s and the bad drivers around here, bigger brakes might be a very good investment.  

BTW, I am looking at the PowerStop pads as well.

Edited Tuesday at 06:02 PM by PrinzII

[dabangsta]

They are much better than the partially worn 96,000 miles ones that they replaced. The little shimmy I was getting before is gone. The slight noise is gone.

 

I haven't really had a chance to emergency type stop test them. I did some moderate braking and sitting in park to not leave hot spots on the rotors, and I tested adaptive cruise but not stop and go cruise. I feel that they are better than the smaller ones. I don't like in a mountainous region but that is where the original ones were taxed. 1 fairly heavy braking session caused them to violently shake next time they got used. I learned from my mistake and use Sport mode and more gap, and stopped using adaptive cruise, as it really does heavy braking when needed.

 

If I was really going for improved brakes for heavier use situations, and not for daily driving with occasional heavy braking, if it wasn't my wife's daily driver, but my daily or weekend driver, I would have done ST calipers and slotted and drilled rotors and pads that need warmed up to work. But I get about 40,000 miles out of pads on those, and after 60k the rotors need replaced. Averaging 25,000 miles a year on the daily driver I don't want to do brakes every 1.5 years.

 

Well worth the update with a normal brake change. Could the fronts have gone another 60k miles? Yes! They were starting to fade as mentioned, and not doing well with excessive braking (which my other vehicle with more aggressive setup handles just fine). I don't think it was the rears only causing the issues. I wouldn't take 20k brakes off and do this.

[PrinzII]

17 hours ago, dabangsta said:

They are much better than the partially worn 96,000 miles ones that they replaced. The little shimmy I was getting before is gone. The slight noise is gone.

 

I haven't really had a chance to emergency type stop test them. I did some moderate braking and sitting in park to not leave hot spots on the rotors, and I tested adaptive cruise but not stop and go cruise. I feel that they are better than the smaller ones. I don't like in a mountainous region but that is where the original ones were taxed. 1 fairly heavy braking session caused them to violently shake next time they got used. I learned from my mistake and use Sport mode and more gap, and stopped using adaptive cruise, as it really does heavy braking when needed.

 

If I was really going for improved brakes for heavier use situations, and not for daily driving with occasional heavy braking, if it wasn't my wife's daily driver, but my daily or weekend driver, I would have done ST calipers and slotted and drilled rotors and pads that need warmed up to work. But I get about 40,000 miles out of pads on those, and after 60k the rotors need replaced. Averaging 25,000 miles a year on the daily driver I don't want to do brakes every 1.5 years.

 

Well worth the update with a normal brake change. Could the fronts have gone another 60k miles? Yes! They were starting to fade as mentioned, and not doing well with excessive braking (which my other vehicle with more aggressive setup handles just fine). I don't think it was the rears only causing the issues. I wouldn't take 20k brakes off and do this.

I have some areas that could really work that combo out.  I am in a fairly mountainous state and that would be a good investment for going downhill on some roads.

Since yours is a 2019, you could do the ST calipers easily.  Mine is a 2018.  Will those calipers even fit?