How To: Convert your N body's rear brakes from drum to disc!

Nas Escobar · 04-30-2013, 03:31 AM

It is a well known fact that Alero's and Grand Am's had rear drum brakes as stock equipment but had disc brakes as an option. Even worse, the Chevy Malibu did not have the option at all, despite using the same Chassis.

After this how to, hopefully that will change.

I will be guiding you step by step on how to convert your car from old fashioned drums to new era discs. I will take 2 posts. This post will introduce you to this mod and hopefully give you an idea of what will happen, the next will be the actual how to.

The real benefit of this (besides look) is that you no longer have to worry about adjusting or changing your rear brake shoes. You would now have brake pads, just how your front has pads. This also sets you on the path to do the "big brake" modification, where you can get F Body (Camaro/Firebird) or Y Body (Corvette) front brakes and Grand Prix GXP rear brakes.

The difficulty of this job is moderate! If you are not comfortable changing your front brake pads, then you should not attempt to perform this modification. Also, if you are on a tight schedule, set a side a weekend (or a full week) to do this. REMEMBER: You do have to bleed your brakes whenever you touch a brake line/hose.

Frequently Asked Questions:
-What do I need to get in order to do the conversion?
-You need to find a donor car that already has disc brakes. It can be at a junkyard, a car that's going to the junkyard, or you can ask for the parts when you see a "part out" thread on the forum.
From the donor car, you will get the full rear spindle (also known as a "steering knuckle") from each side. It is held on by 4 bolts.

-I drive an Alero! Will the parts from a Grand Am fit?
-The Alero and the Grand Am are the same car. Yes they are different, but the overall design is the same. When it comes down to mechanical parts, the Alero and Grand Am are twins, thus the Alero knuckle is the same as the Grand Am knuckle. You can even go to the parts store and ask for Grand Am brake parts, they will have the same part number as the Alero counterpart.

-My Alero is a 2000. Can the parts from a 2004 fit? (or other similar years)
-Yes, they will interchange. The design was the same throughout the years the Alero and Grand Am were built

-Do I have to change the brake hoses?
-No. It is not necessary, but it is RECOMMENDED that you do. These brake hoses are 10 or so years old. You're already bleeding the brakes, you might as well do the whole job while you have it apart.

-Are the brake hoses different between the drum and disc brake setup?
-Yes. The drum brake hose is LONGER than the disc brake hose. The difference is not much, about 1 or 2 inches bigger, but they are different in length. You can re-use the stock hose or purchase the drum hoses if you wish, but the banjo bolt are different in size. At least, mine were, so proceed with caution re-using the banjo bolt.

-I drive a 97-05 Malibu/Classic, but post at Aleromod! Does this apply to me?
-ALWAYS check part numbers. If the drum, hub, brake hose, master cylinder, and spindle are the same part numbers from GM (Yes, I recommend you check GM parts directly,) then you can do this to your Malibu.

A SIDE NOTE: I've been told it can be done, but I'm not sure. Please do your research. If your research lands you here, then proceed with caution. If you found this and just so happen to own a Malibu, do more research. I AM NOT LIABLE FOR ANY DAMAGE THAT YOU DO TO YOUR CAR. YOU ARE RESPONSIBLE FOR CARRYING OUT THE MOD, I HOLD NO RESPONSIBILITY FOR ANY DAMAGES. THIS IS A SIMPLE INFORMATIONAL POST.

-I can't get the bolts off the donor car! What am I doing wrong?
-The bolts are torqued to a certain weight. The top part of the spindle where the struts are attached to are torqued to 133lbnm. Everything else is torqued to 88lbnm. You will need a breaker bar or a torque ratchet to take them off. You will definitely need a torque ratchet to put them back on.

-Can I use the same bolts from my car?
-I personally would take the bolts with me from the donor car, if in case the previous owner had work done around the rear area and you end up with strange sized bolts on your car.

SIDE NOTE: This was the case with my car, I assume someone did a strut job and subsequently lost a bolt. I ended up with a different sized bolt on my struts. I have now fixed that.

-Can I use my old hubs?
-I personally don't recommend it because it's extremely hard to get the hub off. You can't just take off the 4 bolts that hold it in, it requires use of a chisel and hammer to dislodge it from the knuckle. They're on there, and it will be stubborn to get it off. The drums will prove to be harder to dislodge the hubs simply because of all the stuff that's around it. Take the easy way out and buy the hubs with the spindle. You'll thank me later.

-Do the parking brake cables interchange?
No. The cables are attached differently on to the rear brakes, but are attached the same to the cables already in the center of the car.

To better clarify, the drum brake cables are spring loaded, the disc brake cables are clipped on. Also, you will need to tug on the cables where they are attached to the cable that goes to the interior to move them out of their holding place.

I think I'm ready to do the conversion!

Good! A fair warning... This is not an easy task as say, changing a tire or changing your oil. You will get dirty, you will spend a lot of time, but it will all be worth it. Plan accordingly!

You will need the following tools!

Gloves
Hydraulic jack
2 Jackstands
Drip pan (or something where the brake fluid can drip on to)
11mm Wrench
15mm Deep Socket
18mm Deep Socket
3/8 ratchet
Breaker Bar
Torque Ratchet
Vice grips
Flathead screwdriver
Cold beverages
Shade

Parts you will need: (Keep in mind you need these for both sides)

Full Spindle (with hub and parking brake shoe IN GOOD CONDITION)
Rotor
Caliper Brackets
Caliper
Pads
Parking Brake cables
Brake hoses

You can get them all used, or all new. I personally would not get the pads and rotors used. Truthfully I couldn't recommend that the calipers be used too, but try your luck. You may come out lucky.

Now proceed to the next post. You're welcome to print it out, BUT YOU ARE NOT WELCOME TO CLAIM THIS AS YOUR OWN HOW TO: ASK BEFORE REPOSTING AT ANOTHER FORUM.

WARNING: [b][color="Red"]It has been said that the "DORMAN" parking cables are 2" short. Proceed with caution on using "DORMAN" branded parking brake cables. PROCEED WITH CAUTION when purchasing the brake cables.

Nas Escobar · 04-30-2013, 03:32 AM

Because not all of us drive an Alero or a Grand Am, the car will be referred to as "The N Body". It is the name of the Chassis, similar to how the Intrigue's Chassis is called the "W Body".

Step 1:
Remove the hubcap (if any) and loosen the lugnuts on both sides.

Step 2:
Look for a raising/jacking point on the N body. Make sure it can handle the weight of the car. DO NOT jack your car up on the floorpan. It will push the metal upward and you will have a lump on your floor. You should be able to jack the car up on its suspension (IE: The knuckle) without causing damage.

Step 3:
Use the hydraulic jack to raise your N Body up. Depending on the jacking point, you may end up raising the whole rear end of the car. BE CAREFUL IF THIS HAPPENS, AND PROCEED WITH CAUTION.

Step 4:
Place a jackstand where you would normally raise your car up using the normal (GM supplied) jack when changing a flat tire. If you have never done this (and I really hope this isn't the case), it will be the visible piece of metal that isn't flush with the body.

Step 5:
Repeat if necessary. (If the whole rear end didn't go up when jacking the car up). The goal is to have the car resting on both jackstands at the same height.

Step 6:
Remove the lugnuts on both rear tires, and remove the tire. You can put the tires underneath each side of the car, for extra security should some freak accident happen and the car falls off the jackstands.

Your car should now look similar to this on both sides.

Step 7:
Remove the nuts that hold the strut bolts to the steering knuckle. Do not remove the bolts from the knuckle.

Do not worry about the bolts falling out... they need to be hammered out (more on this later)

Step 8:
Remove the bottom knuckle bolt. It is the one with the bushing and the plate that says "this side out"

Step 9:
Remove the sway bar link bolt.

Step 10:
Place the drip pan under the general work area and remove the brake hose.

Step 11
Remove the wiring harness to the hub. That is the wiring for the ABS system.

Step 12:
Remove the nut to the long bolt that holds the steering knuckle to the independent suspension.

At this point, you should see that the knuckle is loose and ready to come out...

Step 13:
With a ballpeen hammer, hit the strut bolts until they pop out.

You should now be able to remove the bolts, and remove the steering knuckle. Your end result should be similar to this...

You will notice I have not said anything about parking brake cable. You can take off the knuckle with the parking brake cable still attached to the drum and set it aside. Notice in the picture, that is exactly what I did. The reason for this is that it will be easier to take off the cables last instead of taking them off the drum first, only to do the job again at the center where both cables are attached.

It is here where you decide which one you do next... removal of the parking brake cables, or install the new steering knuckle. You have to take off the cables eventually.

Step 14:
To remove the parking brake cables, you will ideally want to remove the driver side's parking brake cable first. Pull on it with the vice grips until it gets close to the exit hole. You can use pliers alternatively, and use the vice grips to hold the cable in place. A flathead screwdriver will be ideal to hold the clip in place as you wiggle the cable out.

Step 15:
Repeat the same for the passenger's side. With the driver's side out already, you will see it will be very easy to pull the cable that leads to the actual hand brake towards the passenger's side drum cable, pushing the clip towards the exit hole, freeing the passenger's side cable. You will now have a cable dangling from the center of the car (Sorry for lack of pictures will get some soon).

INSTALLATION OF NEW KNUCKLE

Installation is the exact reverse of what you did to get the knuckle off.
To make it easier, you will want to do Step 8 first, so the bottom of the knuckle is already attached to the suspension. Then push the steering knuckle up, insert the 2 bolts to the struts, install the camber bolt again (step 9), and finally put the long bolt back onto the suspension and knuckle and redo the nut back on it.

Everything but the camber and strut bolts are torqued to 88lb

The strut nuts are torqued to 133lb.

Putting the knuckle back on should be easier than taking it off.

Once the knuckle is on the car, you will now proceed with a normal brake job.

Step 1:
Place the rotor on the hub

Step 2:
Bolt on the caliper brackets to the knuckle

Step 3:
Bolt on the banjo bolt to the back of the caliper. MAKE SURE THE BRAKE HOSE IS NOT TWISTED OR COMPROMISED IN ANY WAY!

Step 4:
Place the pads inside the caliper

Bolt on the caliper to the caliper bracket

Step 5:
Repeat the same process on the other side.

Step 6:
Bleed your car's brakes. For this you will also need some DOT 3 brake fluid.

Step 7:
Install new parking brake. The parking brake is intended to do just that, but it is also an emergency brake, should the normal braking system fail.

You first want to run the driver's side cable to the center, then place it on the back of the knuckle, on a small rectangular clip. You do the same with the passenger's side.

If you did this right, and the parking brake shoes don't need adjustment, then you should have a functional parking brake again.

TIPS

AT this point, you may also want to consider changing your struts. You can purchase quick struts.

There's also a high chance you may have to align your car after this is done. I personally would recommend changing struts and aligning the car once this is done.

Once you do the stuff to remove the knuckle, everything is practically reverse.

Questions, concerns, etc.... feel free to post, and I will edit to clarify anything as needed.

Math-u · 05-01-2013, 01:29 AM

you are the best!!

RalphP · 05-01-2013, 10:20 AM

Correction: Step 9 is not "Remove the camber bolt", but "Remove the bolt holding the sway bar end link". The camber bolt is at the other end of the plates removed in step 12. The unit removed in step 8 is the trailing arm.

Minor nit: It's not a steering knuckle, or at least, it should never be. It's a knuckle. If it's steering your car, you've got massively mundo problems with the suspension.

RwP

Nas Escobar · 05-02-2013, 03:35 AM

Quote:

Originally Posted by RalphP

Correction: Step 9 is not "Remove the camber bolt", but "Remove the bolt holding the sway bar end link". The camber bolt is at the other end of the plates removed in step 12. The unit removed in step 8 is the trailing arm.

Minor nit: It's not a steering knuckle, or at least, it should never be. It's a knuckle. If it's steering your car, you've got massively mundo problems with the suspension.

RwP

Some dumbo honda "tuner" told me it was the camber. I knew it had to do with alignment but I didn't know what that was.

Thanks a ton, I'll edit the how to so it reflects the actual name.

I know it's not a steering knuckle, but some people are slow enough to call it that. I've also heard the term "Spindle" used. Notice I only called it that once. My goal was to make it easy enough that a "novice" could do it.

RalphP · 05-02-2013, 09:18 AM

Quote:

Originally Posted by Nas Escobar

Some dumbo honda "tuner" told me it was the camber. I knew it had to do with alignment but I didn't know what that was.

Thanks a ton, I'll edit the how to so it reflects the actual name.

I know it's not a steering knuckle, but some people are slow enough to call it that. I've also heard the term "Spindle" used. Notice I only called it that once. My goal was to make it easy enough that a "novice" could do it.

If it's desired to adjust camber for the Just Right Driving Experience, then it'd be better to use a proper camber bolt between the strut and the knuckle. One such is this one.

And a correction to my correction - the adjustment off that plate is for toe, not camber.

One thing to add - early Malibus and possibly other cars on this chassis (1997 and maybe some 1998) will need the strut changed, or it redrilled, or the knuckle redrilled, because GM used a different spacing at first. I'd opt for picking a nice neutral year (2000 works for me) and replacing the struts as a quick strut all the time. But that was me *grins*

Speaking of - the wrecking yard has had my Malibu for about three days as I type this, and the rear disc brakes are ... already missing. Thought THAT was interesting.

RwP

Papa Rad17 · 05-02-2013, 11:57 PM

I've done this once. Was a pain in the butt and never got one of the ebrake cables back on. Good write up, will be very useful for doing it on the next one!

Nas Escobar · 05-03-2013, 03:48 AM

I'm not going to lie, I didn't even purchase the ebrake cable. I'm considering getting them later on, when I don't have anything to do.

As far as it being a pain, it's really depending on your mechanical level. I personally find putting them on harder than taking them off, but it's not something that you're iffy about as say... changing a LIM gasket. That, I'd walk away from.

RalphP · 05-04-2013, 12:48 AM

Just as a note - the Dorman cables? Are 2" too short.

I had some used ones out of the boneyard. Never failed me.

(Guy who picked it up for the boneyard after the motor blew? Didn't release the parking brake, and was a bit perturbed about having to drag it up on the flatbed ... )

RwP

Papa Rad17 · 05-05-2013, 01:30 AM

Quote:

Originally Posted by Nas Escobar

I'm not going to lie, I didn't even purchase the ebrake cable. I'm considering getting them later on, when I don't have anything to do.

As far as it being a pain, it's really depending on your mechanical level. I personally find putting them on harder than taking them off, but it's not something that you're iffy about as say... changing a LIM gasket. That, I'd walk away from.

I would just let um hang to but the new one will be stick so I'll have to get figured out one way or another.

Difflay · 05-06-2013, 12:22 PM

you should post up pictures of you putting the disk brakes on it and each step and this write up would be the best one ive seen so far! i think it would help some people

Nas Escobar · 05-07-2013, 02:12 PM

You mean putting the rotor and caliper on? Or the actual spindle?

Difflay · 05-07-2013, 10:43 PM

Everything I'm still a little confused on how exactly it all works

Papa Rad17 · 05-08-2013, 02:28 AM

Quote:

Originally Posted by Difflay

Everything I'm still a little confused on how exactly it all works

Its not bad once you get into it really. Gotta be able to pop bolts free and everything goes together pretty much how looks like its supposed to.

Nas Escobar · 05-08-2013, 02:18 PM

Quote:

Originally Posted by Difflay

Everything I'm still a little confused on how exactly it all works

I was on your position before. It's a lot less daunting than what it seems when you first hear about it.

Look, there's only a handful of bolts. You take them off from the donor car, then take it to your car, take your drums off and bolt the new spindle on. Both spindles are the same, it's just that one has drum brakes and the other has a backing plate with the ebrake. Once the new spindle is on, all you do is a normal brake job. Calipers, rotors, pads, and a brake bleed.

What exactly are you confused about. Installation of the spindle or installation of your actual rear brakes?

ItsMeScottG · 06-04-2013, 10:23 PM

Quote:

Originally Posted by RalphP

Just as a note - the Dorman cables? Are 2" too short.

I had some used ones out of the boneyard. Never failed me.

(Guy who picked it up for the boneyard after the motor blew? Didn't release the parking brake, and was a bit perturbed about having to drag it up on the flatbed ... )

RwP

Damn I wish I would have seen this info before. I started my rear disc brake conversion today and the dorman cables that I bought were about 2 inches too short. I ended up going to NAPA and the parking brake cables that I bought from them worked perfect.

I should have everything I need in order to finish the job now.

Nas Escobar · 06-05-2013, 03:36 PM

I'm surprised you didn't see this on GAOC... I have it there too lol.

Starglow · 06-05-2013, 11:04 PM

I have all the parts for the rear....just need to find the time to do the work. I'm half way through with doing the front upgrade but hit a few snags. Rockauto sent the wrong brake pads, the caliper pin boots are shot, and I have a bad tie rod end.

Should finish up the front this weekend when the parts arrive on Friday and then start work on the rear. Any tips on how to set the rear end alignment? I bought adjustable camber strut bolts to help with the alignment issues I have had since replacing the struts and lateral links.

Also, pay close attention to the rubber boots on the backing plate for the parking brake lever. Mine were torn and I had to buy the complete parking brake shoe replacement kit to get new ones.

The only way I found that worked to remove the parking brake shoes is to first remove the parking brake actuator assembly which then allows more clearance to maneuver the parking brake shoe around and off the wheel hub. Otherwise it won't come off without removing the hub from the backing plate.

Nas Escobar · 06-05-2013, 11:27 PM

I personally don't know how to do that... I just counted how many times I turned the ratchet on each bolt and went from there.

I personally just recommend doing all suspension work and then have the car aligned.

ItsMeScottG · 06-05-2013, 11:33 PM

Quote:

Originally Posted by Nas Escobar

I'm surprised you didn't see this on GAOC... I have it there too lol.

I saw your tutorial a while ago, it's just I didn't see the comment that the dorman brake cables don't work until the other day.

I'm on here, however I'm much more active on GAOC and GAGT.