DIY big brake kit? Learn me

I just posted in another thread a pic, but I went to the junk yard today and stumbled across a 2001 Mercedes ML55 AMG. The calipers caught my eye beneath the 7 spoke wheels. Bright red Brembos.

So, after borrowing a couple of sockets from some very nice folks (and one letting me use his impact), I scored all four brembo calipers for under a hundred dollars.

The wheels that were on the SUV were 17", which, looking it up, they appear to have come off a 430 model.

Ok, so I have the calipers, great, what now? Is it possible to adapt to use on my SW20?  I know I know, the stock set up is good for what Im doing now, and I know someone makes a kit, but that's almost 2k, which I dont have for brakes (about to get paint). So I thought maybe there was a way to do a bbk using these. I dont know, Im looking for some advice, please.

Thanks yall, have a great afternoon and weekend

You'll have to find rotors that are vaguely the same size as the AMG.  They don't have to be exact, but the closer you get to the radius the better.  If the rotor moment of rotation doesn't closely match the radius of the pads, the arc of motion will effect torque on the pads which isn't good.  Shouldn't be hard if you dig through the Toyota parts bin.

Then you'll need to find a master cylinder that has a volume/stroke/bore that matches the calipers.

If you have a band saw or plasma torch you can fab up some brackets to mount the calipers.

There are two key things that would need to be sorted.

First is the caliper carrier bracket and an adapter.

Second is a rotor that fits into the hub diameter, bolt pattern and is the width to play nicely with the calipers. 

Neither is all that easy. 

I like using Centric's online catalog to look up disk and master cylinder sizes of other makes: https://centricparts.com/online-catalog

Coleman Racing makes custom rotor hats.  Just saying 

j_tso said:

I like using Centric's online catalog to look up disk and master cylinder sizes of other makes: https://centricparts.com/online-catalog

Forgive me, I went to the site and plugged in the car they came off of and it pulled up a list of their products for said vehicle.

So, what now? I do appreciate you telling me about the site, it'll give diameter of the rotor, for example, but Im curious how I then look up other makes with that knowledge via that site

You'll also have to figure out how to do a parking brake. 

If it's not too late, go back and grab the rotors, too. They can usually be re-drilled to a different bolt pattern. 

And is selling them on eBay to triple your money, then putting that towards a Toyota-based upgrade an option?

I have no idea what Curtis just said regarding rotor moment of rotation. I've never heard that term.

you need rotors that are the correct diameter and thickness, for sure. You could start with the JY rotors from that car, just be sure you can make the rotor pilot match the hub pilot or vice versa.

Two piece rotors from Wilwood can match an aluminum hat to a rotor that fits your needs.   It may cost about twice or more of a quality rotor but lighter better quality and really cool.

Having gone through this myself, what captdownshift said about adapting the caliper to the spindle is the larger issue.  Since those calipers are not radial mounts, getting the caliper mounting ears to match up to what is on the spindle, and still align properly gripping a rotor, is probably an exercise in futility.  Maybe there's something I'm missing, but when I was working on this, I initially overlooked this as soon as I had a caliper (like the ones you've got) in my hand in front of the spindle, it was painfully obvious that it was never going to fit if I wanted to mount a rotor as well.  

On the other hand, a radial-mount caliper - where the mounting bolts are parallel to the rotor face - means you (or someone) can usually make a fairly basic adapter that will let you mount said caliper to the spindle and have it work with whatever rotor you're using.  

Unfortunately, cars with factory radial-mount calipers are pretty scarce, and the ones that do have them are, well, pretty scarce (and pricey).  Think Porsches, Ferraris, Vipers, etc.  On the ... other other hand, brand new last-gen Viper calipers are surprisingly cheap.  I picked up a pair brand new for I think $500. 

AngryCorvair (Forum Supporter) said:

I have no idea what Curtis just said regarding rotor moment of rotation. I've never heard that term.

you need rotors that are the correct diameter and thickness, for sure. You could start with the JY rotors from that car, just be sure you can make the rotor pilot match the hub pilot or vice versa.

I've never heard the term myself, but from the rest of the term he's talking about the pad trying to twist itself out of its confines, which could lead to damaging the pad material and excessive wear on the calipers.

Good pattern, pad swept area is very close to the rotor's swept area:

Bad pattern, rotor's swept area does not match the pad's swept area, pad is torqued about the center of the pad and creates wear:

NorseDave said:

getting the caliper mounting ears to match up to what is on the spindle, and still align properly gripping a rotor, is probably an exercise in futility. 

That's not that hard.  On the market right now there are dozens of adapters for dozens of different vehicles that didn't come with discs, or people wanted to upgrade the discs or calipers.  Majority of them are simply a chunk of laser-cut steel.  

Mr_Asa said:

AngryCorvair (Forum Supporter) said:

I have no idea what Curtis just said regarding rotor moment of rotation. I've never heard that term.

you need rotors that are the correct diameter and thickness, for sure. You could start with the JY rotors from that car, just be sure you can make the rotor pilot match the hub pilot or vice versa.

I've never heard the term myself, but from the rest of the term he's talking about the pad trying to twist itself out of its confines, which could lead to damaging the pad material and excessive wear on the calipers.

Good pattern, pad swept area is very close to the rotor's swept area:

 

Bad pattern, rotor's swept area does not match the pad's swept area, pad is torqued about the center of the pad and creates wear:

Thank you for that.  It's exactly what I was talking about and I tried to make a graphic representation in (don't laugh) MS Paint... because that is the level of my digital awesomeness.

If you have a pad/caliper that doesn't match the radius of the rotor, the approaching and departing edges of the pad have pretty intense torque exerted on them.  Not happy brakes.

AngryCorvair (Forum Supporter) said:

I have no idea what Curtis just said regarding rotor moment of rotation. I've never heard that term.

 

Moment, as in rotational mass measured at radius.  Technically not a moment since we're talking about brake torque, but in my defense I was at work and distracted.

Curtis73 (Forum Supporter) said:

AngryCorvair (Forum Supporter) said:

I have no idea what Curtis just said regarding rotor moment of rotation. I've never heard that term.

 

Moment, as in rotational mass measured at radius.  Technically not a moment since we're talking about brake torque, but in my defense I was at work and distracted.

 

Quick clarification cause I'm pedantic cause that's what engineers do.  So a moment is the turning effect you get from a force at a distance from a point, torque basically.  Rotational inertia is probably closest to rotational mass at a set distance.  

Mr_Asa said:

Curtis73 (Forum Supporter) said:

AngryCorvair (Forum Supporter) said:

I have no idea what Curtis just said regarding rotor moment of rotation. I've never heard that term.

 

Moment, as in rotational mass measured at radius.  Technically not a moment since we're talking about brake torque, but in my defense I was at work and distracted.

 

Quick clarification cause I'm pedantic cause that's what engineers do.  So a moment is the turning effect you get from a force at a distance from a point, torque basically.  Rotational inertia is probably closest to rotational mass at a set distance.  

Yup... everything that he said ^^^^

I've has success in adapting larger calipers and rotors to improve braking on some  Lemons race cars.  The first one I did was a Festiva, the owner had me install a set of rotors from a Mini and calipers from a Mazda onto knuckles from a Kia.  The calipers were dual piston. I just cut off the mounting ears  from the knuckles and then TIG welded on ears I fabricated out of 3/8" steel where I needed them to be to make everything fit.  As far as I know the car is still being raced in Lemons on the east coast.  I did this mod about 7 years ago.

I did a similar mod to a Ford Escort  and just last year I adapted a 12.9" X 1.1"  Wilwood caliper kit that had been removed from another car to fit on a Nissan 240Z. 

The last were radial mount calipers, this style of caliper mounting is much easier to fit to another car. You just make up new radial mounts to connect the calipers to the stock mounting lugs. A piece of 3/8 steel and two threaded lugs welded in the correct position to make everything fit together.  

I fabricated brackets to mount Brembo calipers (radial mount, 4 piston, forged monoblock) from a Boxster S to my '66 Porsche 912, and upgraded to larger, vented rotors (from a 911 Carrera) at the same time. Cut and drilled thick steel plates to mount to the front spindle where the original caliper mount bolted to, then used 6061T6 aluminum block bolted to that and drilled to bolt the calipers to. Took some time, effort, and VERY careful measurements and drilling/tapping, but it all went together beautifully - and it all fit within 15" dia Fuchs wheels.

Sad thing is, I never got to try them out, I sold the Porsche to a guy who is going to put a Tesla drivetrain in it, he wanted the orignal brakes, so I kept the Boxster calipers and brackets I fabricated, but now have no use for them.

Anybody interested?

In reply to earlybroncoguy1 :

Hrm.  Would they fit on a 914? 

Tom Suddard said:

If it's not too late, go back and grab the rotors, too. They can usually be re-drilled to a different bolt pattern. 

Im guessing a machine shop could/would do that?

In reply to hybridmomentspass :

they could/will.  If you're wondering about redrilling rotors, you'll probably need said machine shop to make your adapters as well.  Even before designing the adapters, it'll be a lot of measuring on your part to get this to work.  Figure out id the spacing of the caliper plays nicely with your current knuckles.  Then find a rotor that will work with everything.  Then figure out how to make it fit under your desired wheel diameter.  Its a good amount of work, and sometimes you might be better off taking your cool find and making money reselling them. 

In reply to Mr_Asa :

What year? If the bolt pattern on the spindles is the same as the 912, they should. The '66 912 originally had thin, solid front rotors and tiny, cast iron calipers. I made the adapters to position the Boxster calipers to be centered on a wider, vented rotor. The hubs on early 911's and 912's had a slightly different offset (because of the thin rotors) than the later models, not much but enough to make a difference.

There are aftermarket suppliers that make calipers adapters for later 911/912's, but they all use the later A-arm/spindle design. I couldn't find any that would work with my orginal A arms and spindle (bolt-on ball joint), so I had to make my own. I think all the 914's used the same front suspension as the later 911's.   

I can't believe no one has mentioned front/rear bias of the calipers based on the piston bore (or if someone did I missed it). Especially when considering the dramatically different vehicles and weight distribution.