Rear Disc Brake Conversion Kit

[jkeith.w]

Sorry Tim, just getting caught up here (not much forum time nowadays)

These are the same pros that [MENTION=118207]midcoma[/MENTION] mentions for the argument to do this mod, but like I said in my response above, how often are you really replacing rear shoes or rear pads? Maybe every 75-100k miles? It obviously depends how you drive for sure but rear brakes don't need servicing all that often.

More if you have a leaking rear seal (probably 30-50% of the 4Runners out there, would you say?)

The drum brakes on our rigs are self-adjusting as well if you use your parking brake like you should and not let the weight of the rig rest on the parking pawl of your automatic transmission. Even the guys who have manual transmissions should use their parking brake because it's a safety back-up.

I agree, if the drum brake assembly is in good working condition and has a proper initial adjustment. I doubt that most of them do at this point, though.

It's true with a disk brake set-up in the rear that you wouldn't have to disconnect brake lines at the wheel cylinders to remove the axles for a rear axle seal job or maybe you're pulling the 3rd member, but again, how often are guys pulling axles on their rigs? And, if you cap off your brake lines when you disconnect them to pull the axles, you lose minimal brake fluid and the bleeding process is beyond easy.

Well, as someone who has done axle seals twice, and still has a non-functioning ABS pump that makes the truck damn near impossible to bleed, I'm all about not having to rebleed the system any more than necessary.
(after two decades of pre-track prep, I'm kinda sick of bleeding brakes, anyway.)

As for self cleaning, I guess people who do a lot of wheeling in muddy conditions or do lots of water crossings might benefit from this functionality.

Not just that, but drums lose effectiveness in heavy rain also - this is why manufacturers moved away from 4 wheel drums. I had a '68 Mustang that was treacherous in the rain - literally no brakes after big puddles. You'd have to ride the brakes to get them hot/dissipate the water so they'd work again. This isn't so much an issue on the rear since it does so little of the overall braking; but why not eliminate that factor if it's feasible to do so?

I'm looking forward to seeing some hard data on the braking performance so myself and others can make an informed decision on whether this mod is worth doing. I would also like to see what the total cost will be for this mod. It will obviously depend on what calipers, rotors and pads you choose, but I'd like to see somebody other that the OP do this mod, report what they spent on parts and how much time they invested in doing the work. These are all things I would like to know before diving into a mod like this.

I'll bet there is no difference in stopping distance with stock tire sizes - the tires are what actually stop a vehicle, and make the most difference in braking distance. There's a chance it affects things with taller tires, but I'm skeptical there also.

As for a cost/benefit analysis; probably not something that is needed on a primarily road-going vehicle. (although I'd still do it, since I hate drum brakes.)

 

[jkeith.w]

They way I see it are as follows:
Better pedal feel
Better heat dissipation
Easier service
Better water/snow/mud shedding
Less wear items (springs, pins, levers etc.)
Newer technology
Maybe a little less weight
No need to bust open brake system

And I just don't like drum brakes. Never have and never will. I'm excited for these.

hahaha - YES!

 

[jkeith.w]

Doing some parking brake research and found this interesting thread. Looks like these calipers don't lock up Mustang wheels while moving either.

Parking brake discussion - StangNet

parking brake vs. emergency brake

 

[mtbtim]

More if you have a leaking rear seal (probably 30-50% of the 4Runners out there, would you say?)

Well sure, every one of these rigs is going to have failed rear axle seals but a lot of these rigs will have never had a rear brake job done by the time the seals start leaking because the shoes last a very long time. I've done the rear shoes on these rigs many times and I don't see it as something incredibly hard. The hardest thing is getting the return spring disconnected and reconnected but once you know the technique to use, it's very straightforward.



I agree, if the drum brake assembly is in good working condition and has a proper initial adjustment. I doubt that most of them do at this point, though.

I might agree with this statement if you're talking about rigs that are in the salt belts of the country where it's common for the bell cranks to become rusted and non-operational. But, in places that don't salt the roads and corrosion isn't a big problem, anyone who uses their parking brake on a regular basis is going to have properly adjusted rear shoes. The problem isn't the fact that the self-adjusting system doesn't work. The problem is a lot of people don't use their parking brake like they should.



Well, as someone who has done axle seals twice, and still has a non-functioning ABS pump that makes the truck damn near impossible to bleed, I'm all about not having to rebleed the system any more than necessary.
(after two decades of pre-track prep, I'm kinda sick of bleeding brakes, anyway.)

Ok, in your situation, because you have a non-functioning ABS pump, bleeding the brakes is a pain in the butt. But, for people with no issues like yours, bleeding brakes is a very straightforward and quick thing to perform. I've done over a dozen rear axle seal jobs at my house and I never said, "Damn, now I've got to bleed the brakes. This sucks!"


Not just that, but drums lose effectiveness in heavy rain also - this is why manufacturers moved away from 4 wheel drums. I had a '68 Mustang that was treacherous in the rain - literally no brakes after big puddles. You'd have to ride the brakes to get them hot/dissipate the water so they'd work again. This isn't so much an issue on the rear since it does so little of the overall braking; but why not eliminate that factor if it's feasible to do so?

My first vehicle was a 68 Bronco with 4 wheel drum so I know what you're talking about here. In a panicked stop, I would literally come off the seat so I could apply more pressure to the brake pedal. It was scary. But, with my 3rd Gens, the only scary braking situations I've experienced is when the ABS kicked in when I wasn't expecting it.



I'll bet there is no difference in stopping distance with stock tire sizes - the tires are what actually stop a vehicle, and make the most difference in braking distance. There's a chance it affects things with taller tires, but I'm skeptical there also.

It will be interesting to see the results of the people who test this rear disk brake system to see if there is any improvements over the stock drum system.

As for a cost/benefit analysis; probably not something that is needed on a primarily road-going vehicle. (although I'd still do it, since I hate drum brakes.)

Like I've said many times on this forum, I'm a function over form kind of guy. If I'm going to be spending significant money and time on something, I'd like to see more benefits than the small ones that have been mentioned for this mod. I understand the arguments that are being put forward to do this mod but I'm not agreeing with the OP, you and others that the supposed benefits are worth the investment. If the braking performance is increased by a sizable margin, that's the kind of benefit I can get behind and give support for a mod like this.

 

[midcoma]

To each their own. :shrug:

 

[Thebeastlives]

Like I've said many times on this forum, I'm a function over form kind of guy. If I'm going to be spending significant money and time on something, I'd like to see more benefits than the small ones that have been mentioned for this mod. I understand the arguments that are being put forward to do this mod but I'm not agreeing with the OP, you and others that the supposed benefits are worth the investment. If the braking performance is increased by a sizable margin, that's the kind of benefit I can get behind and give support for a mod like this.

I agree totally. There are potentially tons of things to fix on a 25 year old SUV and I don't see that replacing the rear drum brakes with disc is 1 of them. Yea it is cool but definitely not worth it. When offroading drum brakes can offer some advantages.

 

[mtbtim]

To each their own. :shrug:

Well of course to each his own but you are putting forth a fairly expensive and time consuming mod which will bring a discussion like we're having. This should be something you should welcome because I'm not the only one that will have similar questions to whether or not this mod is worth it. If the only factor for doing this was to be "Cool and Unique", and you had money and time to burn, this mod is a no-brainer. It oozes cool factor. But, for guys like me, I would like to see a much more arguable reason to spend the money and time to do this mod.

 

[2TH4IST]

End of the day, the only person that can decide if they WANT to do this mod is them and them only. Regardless if it's a performance gain or not. Just the basic benefits of disc over drums is enough for me to do the swap. Yeah it's easy to bleed brakes but if you don't have to do it, it is one less thing to do and buy. Time = money.

Also for the folks that want to lock the rear brakes with the parking brake, that is technically not what it is designed for. Think of this, in a emergency situation do you want to lock the rears up at let say 70 mph on the freeway? Have you experienced doing that? Usually it results in the ass of the truck spinning around. 4runner + top heavy + ass whipping out = roll over. They are for a steady controlled slowing down rate. A skidding tire takes longer to stop.

Now that said, for the folks that want to "drift" their 4runners then add a hydraulic drift brake. We do this all the time on our rally cars. Works like a charm. Just my .02 cents worth. Now back to building my forge and doing usless mods lol.

 

[RandyBobandy]

One of my main reasons for wanting to do this mod is that my drum backing plates are quite rusty and I wanted to replace them, with the amount of time and cost of replacing those (new plates, bearings, seals, etc) I will have a similar amount invested in this disk conversion, so any performance increase is just an added benefit

I also only care that the parking brake will hold the vehicle while parked

 

[Doc2012]

Well of course to each his own but you are putting forth a fairly expensive and time consuming mod which will bring a discussion like we're having. This should be something you should welcome because I'm not the only one that will have similar questions to whether or not this mod is worth it. If the only factor for doing this was to be "Cool and Unique", and you had money and time to burn, this mod is a no-brainer. It oozes cool factor. But, for guys like me, I would like to see a much more arguable reason to spend the money and time to do this mod.

Then don’t buy the bloody kit?

‘Cool man, nice R&D, but not my cup of tea’ would’ve sufficed.


Expensive, eh.

Time consuming, not at all.

This is a fairly ‘bolt in’ mod, and after the addition of the new parking brake ‘power amplifier’ he designed; will take a little more time to install.

You’re basically saying ‘it ain’t broke, don’t fix it’; which is fine.

However, for others that want to have an easy way to access the diff, axle housing, axles, bearings, seals, without having another system to worry about ‘bleeding’ when everything is open, this mod makes it worth it in itself to most people.

And, pretty sure he’s already stated this; he’s had these on his 4Runner for 3 years now, and has had no issues or noticeable brake system performance issues; and plans to run additional tests.


Sent from my iPhone using Tapatalk

 

[mtbtim]

Then don’t buy the bloody kit?

‘Cool man, nice R&D, but not my cup of tea’ would’ve sufficed.


Expensive, eh.

Time consuming, not at all.

This is a fairly ‘bolt in’ mod, and after the addition of the new parking brake ‘power amplifier’ he designed; will take a little more time to install.

You’re basically saying ‘it ain’t broke, don’t fix it’; which is fine.

However, for others that want to have an easy way to access the diff, axle housing, axles, bearings, seals, without having another system to worry about ‘bleeding’ when everything is open, this mod makes it worth it in itself to most people.

And, pretty sure he’s already stated this; he’s had these on his 4Runner for 3 years now, and has had no issues or noticeable brake system performance issues; and plans to run additional tests.


Sent from my iPhone using Tapatalk

It's called having a discussion about the supposed benefits for doing this mod other than being the first kid on your block with rear disk brakes on a 3rd Gen 4runner.

Not time consuming? Compared to what? This mod requires you to basically perform a rear axle seal job to press out the axles from the bearings to get the backing plate off. Then you have to deal with the parking brake install so I'm guessing this would be a minimum 6 hour job for most people.

So, you're saying because you won't have to open the brake system for a future axle seal/bearing repair which is probably 100-150k miles away from being necessary to do again, you're saying most people would think the time and expense to perform this mod would be worth it? Uhhh, OK.

It's hard to say what this job will cost the average person, but I'm guessing at least around $1k. You have the two kits the OP is selling. You need to buy calipers. You need to buy rotors and you need to buy pads. You will also need to buy the bearings, seals and other parts to perform the axle work. This 1k price tag is provided you do all the work yourself. For the guys that don't own a press, they'll have to farm out the axles to a shop to do the press work for them. If you have a press, you'll either have to buy the special service axle tool or sign up for the rental program that was started on this forum and wait your turn to get the tool.

If the test results for the OP's rear disk brake mod aren't any different than [MENTION=168172]sleepydad[/MENTION] results, this means there will be no noticeable braking improvement over the stock set-up. So, the mod will be done by people for the:
1) Cool Factor
2) Ease of Replacing Pads that will need to be changed maybe every 75k miles
3) Ease of pulling rear axles for an axle seal job that's probably 150k miles away from being necessary of doing or ease of pulling axles for some type of work on your 3rd member like a re-gear or locker install. The ease meaning you don't have to disconnect brake lines and bleed the brakes afterward.
4) Benefit of the Self-Cleaning nature of disk brake system

Anyway, I put my two cents into this subject and hopefully it will help someone reading through the thread decide if this mod makes sense for them to perform. Adios.

 

[midcoma]

This should be something you should welcome because I'm not the only one that will have similar questions to whether or not this mod is worth it.

It's not that I don't welcome the discussion, you're just presenting a lot of negativity towards the product as a whole based purely on personal opinion.

Everything with this mod will be based on personal opinion. Right now, there is no hard data on performance. Some people will still think it is wort it based on the other "benefits" discussed in the thread. Others, as yourself, will pass because they don't think the "benefits" are worth the time, money, or effort. Either way, it will depend on the individuals opinion.

Even when there is performance data, it will still come down to personal opinion. Maybe there won't be a performance improvement, but some people might like the improved cooling efficiency or less worry about rusting drums. And that may be enough for them to justify the swap.

As far as the financial commitment, everyone justifies this differently based on their situation and priorities. Maybe someone already has bad seals and/or bearings that they are replacing, so this kit may make sense for them to install at the same time. Maybe others plan to cut off the backing plate to avoid messing with the bearings. Still others might not have any noticeable issues, but don't know if the bearings and seals have ever been replaced so they want to do it for piece of mind. Each person's situation and opinion will be different and people will justify, or pass on, this mod accordingly.

 

[midcoma]

I'd like to thank [MENTION=119443]Twitchstyle13[/MENTION] for volunteering as a tester for this kit.

Here's his 4Runner that we'll be performing testing on.




Testing will be performed at North Carolina Center for Automotive Research (NCCAR). I'm working on getting the track time scheduled.

The plan will be to perform stopping distance testing from the standard of 60mph.

We'll actually be downgrading the 4Runner to the stock brake configuration for initial testing and to establish a baseline for comparison.

Then we'll install the rear disc conversion and test again.

Time permitting, we'll reinstall the TBU and test with Tundra brakes up front and Mustang brakes in the rear.

Looking forward to getting some real world data for this mod!

 

[mtbtim]

It's not that I don't welcome the discussion, you're just presenting a lot of negativity towards the product as a whole based purely on personal opinion.

Everything with this mod will be based on personal opinion. Right now, there is no hard data on performance. Some people will still think it is wort it based on the other "benefits" discussed in the thread. Others, as yourself, will pass because they don't think the "benefits" are worth the time, money, or effort. Either way, it will depend on the individuals opinion.

Even when there is performance data, it will still come down to personal opinion. Maybe there won't be a performance improvement, but some people might like the improved cooling efficiency or less worry about rusting drums. And that may be enough for them to justify the swap.

As far as the financial commitment, everyone justifies this differently based on their situation and priorities. Maybe someone already has bad seals and/or bearings that they are replacing, so this kit may make sense for them to install at the same time. Maybe others plan to cut off the backing plate to avoid messing with the bearings. Still others might not have any noticeable issues, but don't know if the bearings and seals have ever been replaced so they want to do it for piece of mind. Each person's situation and opinion will be different and people will justify, or pass on, this mod accordingly.

Fair enough Dude. I'm just sharing my thoughts on this mod because like I clearly mentioned, the benefits being put forth as the reason to do it aren't that compelling to me and probably to lots of others as well. It's a pretty big time and money commitment to pull this off. If there was a clear braking improvement, like the Tundra Brake Upgrade gives people, I'd be all about it. From the sound of it, the expected test results are going to be no noticeable braking improvement over the stock set-up. It just seems that you and others are reaching pretty hard to make this mod sound desirable other than purely for bragging rights and to put it on their build thread and Instagram page. Yes, it's beyond cool to have rear disk brakes on a 3rd Gen 4runner and I get why people would want to be part of this club. But, trying to tell people that it's worthwhile because you won't have to bleed brakes when you have to pull axles the next time, or it's a major time advantage because replacing pads is easier than replacing shoes seems like you're really grasping for some legitimate reason to perform this mod. Bleeding brakes and replacing the rear shoes on these rigs is beyond easy and not time consuming in the least bit. And, like I argued, pulling axles and doing rear brakes isn't something you're doing that often. I did the rear axle seals and rear brakes on my 2000 80,000 miles and 5 years ago and I haven't had any need to pull the axles or do the brakes since then.

I'm not against modding. My 98 is heavily modded but all my mods make sense to me and serve a purpose that that I can see a clear benefit from. I'm just not seeing your mod fit into that category for me. I don't know the reasons why the guys who've signed up to do this mod are going to do it and I really don't care. It's their rig and their time and money. I just thought sharing my opinion on this mod would maybe get people to do some critical thought before just jumping in. It is a fair amount of work and a fair amount of money to spend for a mod with debatable benefits, my opinion of course.

Anyway, I'm done spewing my two cents. I've said what I wanted to say and I'm done with this topic which I'm sure you'll be glad to read.

 

[Toy2play]

I'd like to thank [MENTION=119443]Twitchstyle13[/MENTION] for volunteering as a tester for this kit.

Here's his 4Runner that we'll be performing testing on.




Testing will be performed at North Carolina Center for Automotive Research (NCCAR). I'm working on getting the track time scheduled.

The plan will be to perform stopping distance testing from the standard of 60mph.

We'll actually be downgrading the 4Runner to the stock brake configuration for initial testing and to establish a baseline for comparison.

Then we'll install the rear disc conversion and test again.

Time permitting, we'll reinstall the TBU and test with Tundra brakes up front and Mustang brakes in the rear.

Looking forward to getting some real world data for this mod!

I just want to say that it's pretty damn cool you put this together and giving the option for people to do it. I agree this is a option comes down to personal choice, but at least we have the choice to begin with. Rock on!

 

[theesotericone]

Maybe others plan to cut off the backing plate to avoid messing with the bearings.

Someone gets it. 5 minutes per side with a cut-off wheel and the backing plates are removed. So, unless you need new bearings there is no reason to press anything for this mod.

 

[RandyBobandy]

Someone gets it. 5 minutes per side with a cut-off wheel and the backing plates are removed. So, unless you need new bearings there is no reason to press anything for this mod.

That’s what I plan to do, like I said before my backing plates are toast and replacing them properly would cost about as much as this disk conversion, so even if there is zero performance increase I’ll still be happy

Also give me an excuse to do the full abs delete while I’m at it instead of just having it disabled like I do now

 

[sleepydad]

[MENTION=139000]phattyduck[/MENTION];
[MENTION=120071]mtbtim[/MENTION];
[MENTION=116195]weekendclimber[/MENTION];
[MENTION=50279]spartacus[/MENTION];
[MENTION=143526]theesotericone[/MENTION];
[MENTION=118207]midcoma[/MENTION];

I think this has been said in pieces and part thru-out but...

My main motivation was:

1. Rust belt had destroyed almost everything about the drum brakes including the lines.

2. Rear seals leaking and soaking everything inside the drums so I needed to do rear seals anyways.

I have to do everything anyways... so why not disc brakes?

In true SleepyDad fashion I went wayyyyy overboard. I kind of wish I had not started the entire endeavor but... in the end I'm glad I have disc brakes that work almost as good as the toyota OEM even if I can't lock'um up.

Had I not done all the work already I would totally be in for this kit.

because I'm from MN... if you have not already watched VGG? do yourself a favor and sit down and give this fine gentleman a watch. if your a DIY wrencher then this guy is for you.

<iframe width="800" height="600" src="https://www.youtube.com/embed/A0ItpbPWEgA" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

 

[jkeith.w]

because I'm from MN... if you have not already watched VGG? do yourself a favor and sit down and give this fine gentleman a watch. if your a DIY wrencher then this guy is for you.

<iframe width="800" height="600" src="https://www.youtube.com/embed/A0ItpbPWEgA" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

surely that's not actual vernacular for MN?? I love it.

 

[2TH4IST]

Just did a junkyard run and picked up a set of mustang calipers for 40 bucks (there are around 6 mustangs there), 7 bucks for a rebuild kit, 35 for the cobra caliper brackets, 18 bucks for pads, 30 bucks for 2 rotors. Thats around 130 for the parts. Add 320 for the parking brake and mount adapters. So around 450 for this conversion. That is cheaper then the TBU, and all 4 rotors and pads on my miata (I hate big brakes lol so expensive on the miata). For me that is 100% acceptable cost. And on top I need to do my bearings and seals as they are over 235k old lol. So kill 2 birds with one stone.

There is no kill like overkill.

But yeah, my car my choice, please stop telling me what to do to my truck. It gets on my nerves.