Rear Disc brake swap questions.

jmr · Post by **jmr** » Tue Feb 13, 2007 12:24 pm

I'm interested in doing a rear disc brake swap on my 2005 SXT.

How do they feel compared to the drums?

Compared to your drums are there any problems with the rear brakes locking up in low traction conditions?

Did you swap the backing plates only or the whole assembly?

bad04srt · Post by **bad04srt** » Tue Feb 13, 2007 12:26 pm

you swap everything except the hubs and spindles i think....the rotors, calipers, all the lines

snkmug · Post by **snkmug** » Tue Feb 13, 2007 1:10 pm

e-brake cables are different

jmr · Post by **jmr** » Tue Feb 13, 2007 2:35 pm

I've got all the parts from a SRT-4 rear disc setup.

I was wondering how they felt when finished with the swap compared to the drums?

Do they lock quicker in the snow/rain than the drums?

Although without ABS anything locks up in low traction condition.

heyitsstock · Post by **heyitsstock** » Wed Feb 14, 2007 12:28 pm

as far as i can remember reading when i wanted to do the swap

most people didnt truely notice a difference...

its like a placebo(sp) you feel the difference because you think your supposed to feel the difference

lambostealth · Post by **lambostealth** » Wed Feb 14, 2007 3:40 pm

You actually lose braking force, the rears should never lock up again, unless you are on ice, which means you are probably going to lock all four anyways.

The reason you lose braking force is because the rear drum shoes are larger than the disc brake pads, so the factory proportionaing valve doesn't let as much fluid to the rears, so if you lose pad area with the same amount of force being applied, you lose braking force.

It's VERY minimal though, I haven't noticed a bit of difference.

blue demon02 · Post by **blue demon02** » Thu Feb 15, 2007 1:15 am

lambostealth wrote:You actually lose braking force, the rears should never lock up again, unless you are on ice, which means you are probably going to lock all four anyways.

The reason you lose braking force is because the rear drum shoes are larger than the disc brake pads, so the factory proportionaing valve doesn't let as much fluid to the rears, so if you lose pad area with the same amount of force being applied, you lose braking force.

It's VERY minimal though, I haven't noticed a bit of difference.

I disagree. With stock pads yes you will lose braking force. But throw on some slotted rotters and some Hawk hp pads and it will stop a lot better. And tires plays a huge part in how well you can stop.

lambostealth · Post by **lambostealth** » Thu Feb 15, 2007 1:49 am

blue demon02 wrote:I disagree. With stock pads yes you will lose braking force. But throw on some slotted rotters and some Hawk hp pads and it will stop a lot better. And tires plays a huge part in how well you can stop.

Well, we weren't discussing Hawk pads and slotted rotors, were we?

He asked if his car would have a greater tendancy to lock up the rear brakes with the swap.

Now if he had asked if he would stop better with the swap and Hawk pads and slotted rotors, I would have answered a LITTLE differently.

I personally have Hawk HPS pads, and drilled/slotted rotors, as well as the swap, and I can say from experience, that it only MINIMALLY is better versus the all stock equipment (meaning drums out back). However, going from the swap on stock rotors and pads, to the Hawk pads and drilled/slotted rotors, did make a decent difference, but I think it only brought it back up to just over stock braking performance.

Also, he didn't ask about tires, so how could you disagree that the car would stop worse based on a question that was answered correctly.

Your words are true, but he didn't ask about changing anything but the rear drums for the discs.

Sorry, but you could have done without quoting me, and saying you disagreed.

hansken_yo · Post by **hansken_yo** » Thu Feb 15, 2007 2:01 am

bad01neon wrote:you swap everything except the hubs and spindles i think....the rotors, calipers, all the lines

I thought you needed the rear hubs? (sorry for the hijack)

lambostealth · Post by **lambostealth** » Thu Feb 15, 2007 5:33 am

hansken_yo wrote:I thought you needed the rear hubs? (sorry for the hijack)

Rear hubs (spindle) from 1995-2005 are identical including SRT-4's.

hansken_yo · Post by **hansken_yo** » Thu Feb 15, 2007 10:20 am

thanks yo... I apparently missed that in the other topic

Post by **Diablo0** » Thu Feb 15, 2007 1:26 pm

lambostealth wrote:Rear hubs (spindle) from 1995-2005 are identical including SRT-4's.

Not completely, the lower attachment for the tension strut is slightly different where on the SRT it's moved inward towards the inside of the car to allow for more clearance of the tension strut. It's not a whole lot but when you sit both next to each and look them over it's noticeable.

blue demon02 · Post by **blue demon02** » Thu Feb 15, 2007 2:50 pm

lambostealth wrote:Well, we weren't discussing Hawk pads and slotted rotors, were we?

He asked if his car would have a greater tendancy to lock up the rear brakes with the swap.

Now if he had asked if he would stop better with the swap and Hawk pads and slotted rotors, I would have answered a LITTLE differently.

I personally have Hawk HPS pads, and drilled/slotted rotors, as well as the swap, and I can say from experience, that it only MINIMALLY is better versus the all stock equipment (meaning drums out back). However, going from the swap on stock rotors and pads, to the Hawk pads and drilled/slotted rotors, did make a decent difference, but I think it only brought it back up to just over stock braking performance.

Also, he didn't ask about tires, so how could you disagree that the car would stop worse based on a question that was answered correctly.

Your words are true, but he didn't ask about changing anything but the rear drums for the discs.

Sorry, but you could have done without quoting me, and saying you disagreed.

And again you are not compleatly correct. If you have crappy tires then the rear brakes will lock up very quick (regardless of what kind of brakes you have) but if you have good tires then they will grip the road better and not lock up as quick.

I first had stock pads when I did the disc swap and I didn't notice any differance. But when I swaped on the hawks I noticed one very huge differance. Under hard braking the back didn't pop as quick this resulted in more weight beeing kept in the rear thus transfering the braking force more evenly throughout the fronts and rears. And this then resulted in much better stoping power in the front as well as the rear.

And you answered a question based on an question that he wasn't asking right to get the info he wanted. Just simply telling someone that there rear brakes will lock up quicker if they have bigger pads is only partly correct. How quick your brakes lock up is compleatly controlled by the tires and or driving conditions you are driving in it is also effected by the driver. you can take a car with two differant drivers and stop complealty differant. If you lock up the tires right away and learn to manaualy pump the brakes and stop that way you will stop quicker and faster then if you just stomped on the brakes and waited for them to grab. Thus why ABS is standered on almost all vehicles now. More and more vehicles are being sold with 4-wheel disc brakes standerd. If Drums stoped better then why don't they use them more? Its simple the way Drums work are by far not as strong as the design for Disc's. Yes the pad is bigger doesn't do any good if you can't make it clamp worth a crap.

jmr · Post by **jmr** » Thu Feb 15, 2007 4:37 pm

Thanks for the info guys.

I'm using stock replacement pads so nothing spectacular there. My concern was that the rear disc would lock up quicker than the stock drum brakes it came with. It sounds like that's not a issue though.

I wanted to swap to disc because they are easier to service, self adjust better, more swept braking area, better design and they look better.

lambostealth · Post by **lambostealth** » Thu Feb 15, 2007 7:16 pm

blue demon02 wrote:And again you are not compleatly correct. If you have crappy tires then the rear brakes will lock up very quick (regardless of what kind of brakes you have) but if you have good tires then they will grip the road better and not lock up as quick.

I first had stock pads when I did the disc swap and I didn't notice any differance. But when I swaped on the hawks I noticed one very huge differance. Under hard braking the back didn't pop as quick this resulted in more weight beeing kept in the rear thus transfering the braking force more evenly throughout the fronts and rears. And this then resulted in much better stoping power in the front as well as the rear.

And you answered a question based on an question that he wasn't asking right to get the info he wanted. Just simply telling someone that there rear brakes will lock up quicker if they have bigger pads is only partly correct. How quick your brakes lock up is compleatly controlled by the tires and or driving conditions you are driving in it is also effected by the driver. you can take a car with two differant drivers and stop complealty differant. If you lock up the tires right away and learn to manaualy pump the brakes and stop that way you will stop quicker and faster then if you just stomped on the brakes and waited for them to grab. Thus why ABS is standered on almost all vehicles now. More and more vehicles are being sold with 4-wheel disc brakes standerd. If Drums stoped better then why don't they use them more? Its simple the way Drums work are by far not as strong as the design for Disc's. Yes the pad is bigger doesn't do any good if you can't make it clamp worth a crap.

You're still not seeing the point, he asked if he would lock up more with a swap.

So, you have to assume that he is not changing any other aspect of the car (including the tires), and obviously it would be the same driver.

The answer is a simple NO. The rear brakes that he asked about, would have less of a tendacy to lock up with simply swapping the drums for discs.