# 4 Wheel Disc Brake Conversion???



## obermd (Mar 3, 2012)

I know we've had several people look into it but no one has followed through due to cost and difficulty. As long as your rear drums are adjusted properly (pull the hand brake up - it should reach top about 2 inches in front of the center console) the drums on this car are more than sufficient to stop the car quickly. Remember, you do have disc brakes in the front.


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## pandrad61 (Jul 8, 2015)

In theory you can swap the whole rear axle assembly from a crashed front cruze. Should have everything you need


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## goochman (Mar 20, 2015)

Before buying the Cruze I did a bit of research on Drum vs Disc. Bottom line is for normal driving Drum brakes are as good as disc brakes. Disc brakes are better at heat dispersion when you are using your brakes *alot*, otherwise you wont see much difference between the 2 with a properly adjusted drum brake.

I also believe that the braking is like 90% front, 10% rear or such?


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## pandrad61 (Jul 8, 2015)

more 70-30 but yah for street driving dont bother, now if you track or drive very aggressively could be good. again try to by a rear whole assembly so you have everything and you have an extra axle assembly just in case


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## Eddy Cruze (Jan 10, 2014)

pandrad61 said:


> In theory you can swap the whole rear axle assembly from a crashed front cruze. Should have everything you need


How would that work again, I'm not familiar with your theory?


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## _MerF_ (Mar 24, 2015)

Yeah the biggest question I would have here is "why"? Can't imagine a scenario where this would be needed from a performance standpoint.


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## pandrad61 (Jul 8, 2015)

if you take the whole rear axle assembly off a cruze with disk brakes rear everything is already done. the mounting points are all lined up and you dont need to cut, weld, measure,modify but simply swap. it saves time and head aches but cost more money. at most maybe you need to adjust some brake lines


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## CDNCRUZIN (Nov 24, 2015)

Thanks everyone.. the main reason is that I find when I apply the brakes, I feel like Fred Flintstone lol... foot through the floor style.. they just seem so soft compared to all disc brakes. I don't intend on taking this to the track but where I drive, you need to stop on a dime thanks to the ppl around you that got their license from a crackerjack box! LOL


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## CDNCRUZIN (Nov 24, 2015)

it does seem like far too much work for me tho so i'll just have to get used to them I guess!


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## spacedout (Dec 7, 2010)

CDNCRUZIN said:


> The main reason is that I find when I apply the brakes, I feel like Fred Flintstone lol... foot through the floor style.. they just seem so soft compared to all disc brakes.


Your exactly right, if you drive a cruze with 4 wheel disc brakes its a night an day difference on the pedal feel. Unfortunately for me I have a 1LT with drums and HATE the pedal feel, makes the car feel like every GM car from the 1980's I drove. 

At least the 2016+ cruze GM has put 4 wheel disc brakes as standard.


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## pandrad61 (Jul 8, 2015)

to try to help run racing brake fluid like ate racing blue or motul dot4. this helps firm up the feel a bit. use semi metalic sport front brake pads to help with initial bite, the biggest factor to your brake distance is the tires. if you put some more sticky sport tires vs economy the abs can apply more pressure without lock u


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## CDNCRUZIN (Nov 24, 2015)

exactly spacedout... and thanks pandrad61.. i'll try that! I've got some nice rubber going on in the summer and winters are going on tomorrow so we'll see how that helps!


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## Eddy Cruze (Jan 10, 2014)

CDNCRUZIN said:


> it does seem like far too much work for me tho so i'll just have to get used to them I guess!


In the models that have the Disc/Drum combo think of it as GM cutting corners and being cheap. While other makers do the same thing it is right up there with roll up manual windows as far as I'm concerned. However from a safety point of view there is little if no compromise when it comes to stopping power. It is though more expensive doing routine maintenance on drum brakes. This was one of the first things that bothered me about the 1LT.


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## pandrad61 (Jul 8, 2015)

i refuse to buy any vehicle with drum brakes besides vintage cars and motorcycles. i hate working no drums and the pedal does feel like mush


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## Terryk2003 (Sep 22, 2014)

If your pedal feels soft you may wanna make sure the rear drums are adjusted properly. I have rear drums and have a solid pedal.


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## chevrolet1616 (Nov 1, 2013)

Took my Cruze on VIR for Holiday laps, the drums have an issue with warping under high heat loads. Smooth on the first stop but as they heat up, it gets worse. I have a video of the drive in case anyone is interested.

I do notice the vibration gets worse if I'm coming down off a highway, from 70 to stop in about 1/4th to 1/2 mile of braking. Anyone notice a similar issue?


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## _MerF_ (Mar 24, 2015)

It's an economy car, folks. Not a street machine.


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## pandrad61 (Jul 8, 2015)

and your point is? many "economy" cars can be fun too. ford fiesta,Mazda 3, mini cooper are economy cars but are still fun. for daily driving drums are just fine but for track time they suck. just because a car is economy does not mean it cant be made better or more fun. the old dart was a economy car that was made into so much more


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## obermd (Mar 3, 2012)

CDNCRUZIN said:


> Thanks everyone.. the main reason is that I find when I apply the brakes, I feel like Fred Flintstone lol... foot through the floor style.. they just seem so soft compared to all disc brakes. I don't intend on taking this to the track but where I drive, you need to stop on a dime thanks to the ppl around you that got their license from a crackerjack box! LOL


Get the rear brakes adjusted. We know the drums on the 2011 and 2012s weren't adjusted properly. There shouldn't be that much play in the brake pedal, even with rear drums.


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## _MerF_ (Mar 24, 2015)

pandrad61 said:


> ... just because a car is economy does not mean it cant be made better or more fun. the old dart was a economy car that was made into so much more


No, I totally agree! I'm just saying there seems to be some lofty expectations about what the stock design of the rear brakes...complaining about the rear drums not holding up at VIR (fun track, btw!) or the brake pedal being soft are kinda silly, considering the point of the car off the lot.


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## pandrad61 (Jul 8, 2015)

i do agree that you cant expect much from OEM since it is a economy based car not a performance platform. but he is on the right path to making the car more fun, efficient on the road and track with better and easier to work on brakes. i think most everyone here knows they drums are only absolute stock driving and not performance, now a few things can be done to improve them yes but they are just inferior this OP wants to swap them from drums to rotors


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## jblackburn (Apr 14, 2012)

chevrolet1616 said:


> I do notice the vibration gets worse if I'm coming down off a highway, from 70 to stop in about 1/4th to 1/2 mile of braking. Anyone notice a similar issue?


If your car is like mine, that's your front brakes doing the shaking. The stock rotors/pads are EXTREMELY bad at bleeding off heat and start to overheat easily. A decent set of pads and rotors later, I'm very happy with braking performance from highway speeds - not a hint of that shaking crap since, even after hard 70-20 mph stops that traffic seems to do for no reason at all.


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## _MerF_ (Mar 24, 2015)

jblackburn said:


> ...even after hard 70-20 mph stops that traffic seems to do for no reason at all.


Man I don't miss I-95..lol


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## CDNCRUZIN (Nov 24, 2015)

obermd said:


> Get the rear brakes adjusted. We know the drums on the 2011 and 2012s weren't adjusted properly. There shouldn't be that much play in the brake pedal, even with rear drums.


Thanks! Will definitely get them adjusted.. and on another note, I just ordered my Trifecta tune!!!!!!


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## 170-3tree (Nov 4, 2014)

I've been doing autocross with my Cruze and the brakes (drum) are fine. I flushed with new fluid the day I bought it and that firmed it up some and made a minor adjustment to the rear, which helped a bit too. I plan on doing front brakes soon (probably hps5.0 pads and ebc ultimax rotors) and am trying to talk to carbotech about relining my shoes with some better finish, but so far, they haven't been bad at all. 

This is my first car with drums out back and it hasn't bothered me except for the look through my wheels.


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## Merc6 (Jun 8, 2013)

Add 13 to the list. I got rotor shakes 9000 miles into ownership and couldn't even e brake hold on a hill out of gear.


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## pandrad61 (Jul 8, 2015)

*Merc6* i think i may on that list sooner rather then later. monthly auto crosses and teaching the ball and chain how to properly drive so there is a lot of brake action.

*170-3tree* drums aint all that bad i just hate doing maint on them. hate all the wires and adjustments. rotors are easy and i like easy


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## CDNCRUZIN (Nov 24, 2015)

well guys the tune was installed last night so now I REALLY need to get my drums adjusted! LOL! This kid is super happy with his tune! What a friggin difference! 

Car goes in today for a rear brake inspection..


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## obermd (Mar 3, 2012)

Merc6 said:


> Add 13 to the list. ... couldn't even e brake hold on a hill out of gear.


Not able to hold the car on a hill is the symptom you need to report to your service department to get them to adjust your rear drums under warranty. Another symptom of this is excessive nose dive during hard braking. The Cruze's nose doesn't dive that much once the rear drums are set properly.


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## Robby (Mar 1, 2013)

obermd said:


> Not able to hold the car on a hill is the symptom you need to report to your service department to get them to adjust your rear drums under warranty. Another symptom of this is excessive nose dive during hard braking. The Cruze's nose doesn't dive that much once the rear drums are set properly.


I rarely get involved with the 'Rear disc vs Drum' discussion because it can incite a riot of sorts, but as a reminder:

In general, since we know that the rear brakes only are asked to provide around 20 to 30 percent of total braking power, a properly sized and designed drum design is quite capable of providing all the stopping power the vehicle needs.
Rear disc setups on general purpose cars exist for just a few reasons.

Primarily, since most operators have little idea what really is going on back there, it is more of a 'I need to have it because I heard it is good' type thing.
So, for the most part, it is actually a advertising ploy.
To those sensative to pick up on the 'feel' what you actually are noticing is the immediate 'take up' that comes with a all disc system.
This is a result of the disc pad clearance always being at optimum...there is no mechanical adjustment (beyond hand brake adjustment that occurs with each hand brake application) required.
The same feel is attained once the rear shoes have fully bedded to the drum diameter and have been correctly adjusted for the bed in.
Although it won't change the brake application during normal driving, the hand brake cables also have to be adjusted for the initial bed in and cable stretch.

The proof of how limited the rear brakes workload is shown in their lifespan which is generally three times that of the same car with a rear disc system.
The rear pads of a disc system are generally a third smaller as well as a smaller disc diameter and, the pad material is much softer so it can generate heat. Remember that heat and pad destruction is required for braking......it takes heat to get it rolling, it must make heat to get it to stop.

That less than stellar heat production really shows itself here in the midwest as rust. The rotors rust so badly they generally require replacement with each rear pad replacement and the caliper slide pins never dry and begin to bind the caliper.

The somewhat better protected hardware under the top hat of a drum generally live a rather calm life in comparison.
It was mentioned that shoe replacement (when finally needed) is a pain.........And it sure is if you do the job without specific brake spring tools and spring pliers.
I've seen guys do it with pliers and screwdrivers......springs flying around, bleeding hands, cursing.

Gotta tell ya, with the right tools I can hang shoes faster than most can do pads what with the caliper service that should be done during the process.

GEEZE!
Did I get sidetracked!

I was going to (and still am) respond to Obermd's comment about nosedive.

The beauty of a trailing axle rear suspension on a front drive car is how it responds to hard braking.
When the rear brakes are correctly adjusted, the lever action of the brakes on the axle cause it to rise.....in so doing, the rear of the car lowers.
As a result, adjusted correctly, the entire car lowers on hard braking.

You can observe this by fully applying the hand brake and brake torqueing the car in a forward gear......stick shift guys can do it by putting it in first and loading the clutch.

Going back to adjustment of drum systems, if you want to keep that solid feel that a well adjusted disc/drum system can provide get into the habit of removing the drum(s), cleanout the accumulated dust, sand off the rust ridge at the outer bell area of the drum, and touch up the adjustment to a light drag.

Although drum systems are self adjusting they do not 'add a click' on the adjuster wheel until they are waaaaay out of adjustment and shoe to drum clearance is in 15 to 20 thousanths range.

That is all,

Rob


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## CDNCRUZIN (Nov 24, 2015)

Well it's official.. my drums were adjusted by a poorly trained monkey at GM.. they're now properly adjusted and feel just fine! Thanks again everyone!


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## 170-3tree (Nov 4, 2014)

they ALL were from the factory. Lol. But fixing it makes world's of difference doesn't it??


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## Merc6 (Jun 8, 2013)

obermd said:


> Not able to hold the car on a hill is the symptom you need to report to your service department to get them to adjust your rear drums under warranty. Another symptom of this is excessive nose dive during hard braking. The Cruze's nose doesn't dive that much once the rear drums are set properly.


I got it fixed finally at 20K miles.


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## obermd (Mar 3, 2012)

CDNCRUZIN said:


> Well it's official.. my drums were adjusted by a poorly trained monkey at GM.. they're now properly adjusted and feel just fine! Thanks again everyone!


This issue has been so consistent I wonder if the machine that does the rear brake assembly at Lordstown doesn't have the right adjustment set for the car. Maybe there's a communication failure between the factory and dealerships with the dealerships not having been told the Cruze requires rear brake adjustment prior to customer delivery.


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## Robby (Mar 1, 2013)

obermd said:


> This issue has been so consistent I wonder if the machine that does the rear brake assembly at Lordstown doesn't have the right adjustment set for the car. Maybe there's a communication failure between the factory and dealerships with the dealerships not having been told the Cruze requires rear brake adjustment prior to customer delivery.


No......it has nothing to do with the initial adjustment.
The shoes must wear to the point the entire shoe conforms to the drum.

If we were to remove the drum and inspect the shoes at about the five hundred mile point we would find that only about 60 to 70 percent of the shoe is making contact with the drum.
The tops of the shoe, that are acted upon by the wheel cylinder, will show full contact and as you follow the shoe downwards towards the anchors (the fixed pivot point at the bottom of the backing plate) will show progressively less contact trailing off to no contact.
This is why the first adjustment takes quite a few 'clicks' of the adjuster to restore pedal travel.

At the 3000 mile point, another adjustment can take place but may only require five or six 'clicks' to reestablish pedal travel and it will be noted that around 90% of the shoe will show contact.
A final adjustment at the first tire rotation (7500 miles) will only require a click or two and from that point forward, a clean and possible adjustment touch up should occur with each following rotation since it can be assumed the shoes are now fully 'bedded' to the drums.

The only way this could be avoided is if a process called arcing was added to the assembly process.
The shoes are put in a fixture that is adjusted the ID of the drum it will be used with. The process involves grinding a bit of material off the shoes so they end up perfectly 'arced' to the drum.
Drums measured 'as new' will vary a few thousanths and this is the only process that could be added to eliminate the need for a few adjustments during the break (bed) in period.

Since the vast majority of drivers don't pick up on a low (but still very effective) brake pedal, this process is rarely used anymore. And, of course, the added assembly process and associated costs.
It was a fairly common practice in the days of four wheel drum systems as a step taken after a drum was resurfaced.
The ID was now larger but the shoes were sized for the original ID......not arcing the shoes to the new dimension would result in a brake job needing readjustment several times during the bed in process.

But as I said before.....once you have gone through the break in process and subsequent adjustments of a rear drum system as found on the Cruze, you likely will not need rear brake replacement for over 150,000 miles or more.

Rob

Forgot to add: keeping the rear shoes adjusted lengthens the service life of the front pads since it reduces their workload.


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## Jaz (Jan 7, 2016)

I know you guys didn't get the Cruze until 2011. But even the crappy Korean made series1's we have over here have disc corners. I have the Australian made S2, which is just better built


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## 203-CRUZER (Dec 27, 2015)

Mine does the same thing, as you're describing! I am one to drive my Cruze hard. Didn't know, there was others, who's Cruze, did the same thing. I'm waiting for my brakes from R1 - drilled n slotted rotors and hawk pads......and I will be keeping the rear drum brakes. Can't wait to see/feel if there's a difference in stopping power from factory equipment!




jblackburn said:


> If your car is like mine, that's your front brakes doing the shaking. The stock rotors/pads are EXTREMELY bad at bleeding off heat and start to overheat easily. A decent set of pads and rotors later, I'm very happy with braking performance from highway speeds - not a hint of that shaking crap since, even after hard 70-20 mph stops that traffic seems to do for no reason at all.


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