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Improving JK braking

8K views 49 replies 24 participants last post by  DR Drake Ramore 
#1 ·
Hey everybody,

Two weeks ago I had to do an emergency brake. I really jammed my foot on the brake, and the abs kicked in -which is fine - and instead of arriving to a complete stop the vehicle proceeded to move couple of feet before it stopped. My issue with this ordeal was that it occurred at a very, very low speed, if I'm exaggerating it was 10 mph which kinda freaked me out. I would point out that when I brake normally, or even wit a tad vigor, my jeep brakes just fine.

In view of this, I would like to upgrade my braking. I know it's not possible to get a jeep to brake like a sports car, or even like a sedan (maybe if you are willing to spend ridiculous amount of money) but I want to do what is reasonably possible. I watched the teraflex big rotor kit install, and at the end they do a bit where they show you the difference in braking distance, but honestly I was not impressed. I already changed tyres from crap Goodyear tyres that were installed to bf goodrich ko2.

What would be my next move? What pads/rotors are recommended? Will a bigger booster really make any difference in such a vehicle?
 
#14 ·
Not true...try driving on ice and slam in the brakes and see what happens.

I wonder how soon after the OP started his Jeep/crossed the calibration threshold before he had a hard brake...

Most ABS systems have to some sort of calibration everytime a vehicle is started...my Audi, wife's Mini, had father's pickup, my Jeep, all sometimes 'would grunt' or make noise at 10-15mph under various conditions after starting.

I run into all the time with the jeep - I have a steep hill and sharp turn that requires decent braking almost immediately after my driveway where the ABS does weird crap until I initially cross a speed threshold...it feels like the brakes arent working and the pedal reacts oddly.

I have never noticed this behavior in 4x. I think most driver's never notice it because their driveway is flat...

All that being said, I think the brakes on the jeep are inadequate and have contributed to far too many near misses. I believe if I had bigger brakes, I would have been able to stop in time to avoid a jackass that ran a red light. I rented suburbans and full size vans that was far heavier whose brakes felt more responsive and tighter.

I'm going to be replacing my TF big rotor kit with the Mopar BBK and some sort of bigger rear kit on my next brake maintenance cycle.

via pyramid energy waves.
 
#6 ·
What year Jeep and how many miles on the stock brakes? Perhaps new fluid and steel brake lines will do you assuming you have put up some good miles already? Always worked in my vehicles without having to spend locker money in front brakes, though in essence bigger rotors and pads will help for sure.
 
#16 ·
Ugh...that was similar to me. I was slo-cruising about 35 in a 45mph zone. Old guy blew a red light as I entered the intersection. Out of the corner of my eye, I saw a car going too fast to stop.

Thankfully, I was anticipating the accident and was already jamming hard on the brakes - bottom line was I felt like the brakes didn't respond as they should have. Old dude had no idea the light was red (even though all 5 lanes of traffic on his side were stopped...)

I ended up hitting his rear tire/quarter panel going like 25.

If I had better brakes would have missed him/only clipped his rear bumper. Instead I ended up with a bent frame (no airbag deployment for me - his side curtains & steering wheel all went off ) - all the impact energy went right the crappy OEM bumper into my rt front tire.
 
#22 ·
You might want to consider a better tire for the roads.. like Michelin, and have the k02 for the trails. With bigger brakes come potential wheel clearance issues as well. Obviously, it can get expensive pretty quick.

I hear ya though.. I'm still on the OE Wranglers and they leave a lot to be desired. I've had to hit the brakes hard from about 40 MPH and a couple times slower than that. It's a little unnerving. Boy does the nose dive something fierce as well... LOL. Makes me want to upgrade the shocks along with tires/calipers/rotors/pads.
 
#26 ·
What would be my next move? What pads/rotors are recommended? Will a bigger booster really make any difference in such a vehicle?
I've been there with my '13... and my '91. Before spending a bunch of money on a big brake kit with new calipers, pads and all the other stuff, I would install stainless steel brake lines first to see if the pedal pressure improves with low speed emergency stops.

My '13 has done that low-speed soft pedal ABS dance before and I wouldn't react based off that alone - because I don't think it has anything to do with the size of the rotors and pads... especially at low speed.

I've stood on my brakes on three different occasions with that same scenario and the ABS did its job.... scared the hell out of me, but the Jeep howled and stopped.

Now, if you've increased the tire diameter and width significantly then that's a different issue and you may need larger brakes.

Try the braided lines first if you can't live with the periodic soft pedal..

.
 
#27 ·
My on road stopping wasn't the best but okay. I had grown accustomed to allowing a little more stopping distance but it could have been better. However, I had an experience on a trail that caused me concern. Had my Ruby in 4Lo, lockers on and wanted to back up 6". She didn't stop at 6", actually had to give them a quick pump. Even in 4Lo 1st gear she would be a bear to "hold" on the trail. Did a lot of looking at several kits out there and after researching I did the following 2 steps.
First step was installing the stainless braided lines that came with the lift (derrr. the stock ones were "long enough" so i didn't do it during lift install).
Second step was installing the Teraflex rotor upgrade kit on the front. Goes up to a 13.1" diameter rotor and relocates the caliper.
Instant improvement. On the trail I can hold with the tires dropping off a rock and she stays. On the road she stops way better.
There are lots of options out there for various amounts of money. This worked out great for my rig, she is a 2dr and I have been very weight conscious with the mods I have installed. A 4dr may require more upgrade.
Note on the Big Brake kits: The Mopar kit is in the same price range as the Teraflex kit but the Mopar kit includes both the booster and the master cylinder.
 
#29 ·
Teraflex rotor upgrade kit on the front. Goes up to a 13.1" diameter rotor and relocates the caliper.
This does look like an affordable option. Since the caliper does not change, it makes me wonder if the OEM rotor is not taking full advantage of the current pads? Seems a bigger rotor would require larger pads to accommodate the size increase. I see they have a big brake upgrade kit and that looks very affordable compared to others I've seen.

I'm not a big fan of the braided lines. It doesn't improve braking performance as far as I know... just the feel of the pedal, which I get. I've had them on other vehicles and they were nice for track days and such so you could have a more consistent brake feel.
 
#34 ·
I just ordered the Mopar BBK. If everything goes right, I should have it in a week. I went with this because of what you get. I looked @ TF and I almost went with that, because of the cost. Then as I started looking into it more, watched TF install video and learned if you want it to work @ it's full potential you need the master cylinder. When I added the cost together, it cost more than the mopar kit. Plus I didn't care for rotors that were from a ram and drilled for a JK. That is just me though.
 
#35 ·
#36 ·
I did the Mopar BBK up front and the Teraflex big rotor kit in the rear. I have the master cylinder and brake booster for the Mopar kit but have not installed it yet. The difference in braking over stock is huge. I will eventually get around to installing the master cylinder and booster but it is not a huge priority. Stopping performance is impressive.
 
#37 ·
Kewl, glad it's a big improvement. Looking forward to an update after the master cylinder and booster are installed. I gotta stop clicking on all these threads, it makes me want to buy things, hehee :pc-ouch:. But seriously this is a very important upgrade IMO, with lifts, extra weight from parts and oversized tires it will get the Jeep to stop better then when it was stock. If or when you need to stop fast to avoid a possible accident it will pay for itself the first time.
 
#40 ·
asfaik, abs kicks in regardless of your speed.

The mopar kit is a bit cheaper than the TF one (but I'm not sure) hopefully I will have the prices sorted tomorrow. I have read some good things about Baer, but I don't want to change my wheels and spacers could cause some... discomfort with authorities where I live.

As far as tyres go, the ko2 are so, so much better than Goodyear wranglers, in terms of braking and comfort (though a bit more noisy with windows down), so that is step one.

While I believe I can install the brake kit myself (and I do have all the tools I need, except of a torque wrench which I can borrow) I much rather have a professional deal with the brakes.
 
#41 ·
The Mopar kit includes the master cylinder and booster. The Teraflex kit does not. The price is about the same so the Mopar kit appears to be a better value. The Teraflex rotors are 1/8 in larger in diameter if that makes a difference. I did go with the Teraflex rotors in the rear and it made a much bigger difference than I thought it would. It uses stock size pads, but it really firmed up the brake pedal feel. This was even after I installed the Mopar front kit. I will get around to installing the master cylinder and booster this fall or early spring. I suppose that will improve performance even more. I have tested the Jeep. It already stops considerably better than stock with the new brake configuration so the MS and BB will just be icing on the cake.
 
#42 ·
The Mopar kit includes the master cylinder and booster. The Teraflex kit does not. The price is about the same so the Mopar kit appears to be a better value. The Teraflex rotors are 1/8 in larger in diameter if that makes a difference. I did go with the Teraflex rotors in the rear and it made a much bigger difference than I thought it would. It uses stock size pads, but it really firmed up the brake pedal feel. This was even after I installed the Mopar front kit. I will get around to installing the master cylinder and booster this fall or early spring. I suppose that will improve performance even more. I have tested the Jeep. It already stops considerably better than stock with the new brake configuration so the MS and BB will just be icing on the cake.
Interesting observation.

I've read JK's have more brake bias (proportion) toward the rear, as opposed to the front. If someone just changed the rear rotors and left everything the same, I wonder what the result would be?

This would be an easy test...

If the pedal lag (softness) is related to the abnormal rear bias, this could fix that problem.

Food for thought...

.
 
#45 ·
I'm running the TF rear non slotted rotors with stock pads on my 10 jk. Haven't installed my purchased Mopar BBK front kit yet. About 6K miles on them. It stops a little better than the stock setup. My rear oem setup was still ok at 49k. If I had to put a number on it I would say feels 10-15% better. Was an inexpensive upgrade considering I wanted to replace the rear rotors to match the size of the new fronts as closely as possible. Maybe I will get more miles out of the rear pads now. I like that the drum portion is finned also on the TF.
 
#46 ·
Picked up the Mopar kit a week ago and will be doing the install one day this week. Just wanted to say, as an old wrench slinger from way back, it's really a bad idea to try to use larger capacity calipers without the bigger master and also a bad idea to use the bigger master without the bigger booster. A good understanding of how the complete system works is a great way to start. This is what made the Mopar kit the smart choice for me. I see no real gain to be had from upgrading the rear beyond the increase to be gained from the bigger master and booster. Assembling a system piecemeal without proper testing and the equipment to do so just makes no sense to an experienced mechanic.
 
#47 ·
I agree with this for the most part. My Jeep is not my daily driver so I don't mind doing it slowly. They guys at Teraflex seem to think that the booster and master cylinder are not needed on 2012 and newer Jeeps as those parts are larger or more efficient in the newer Jeeps. I do intend on installing them but has not been a big issue and I assure you the braking performance is considerably better than what it was before. No, I am not a professional mechanic but I have been turning wrenches on my own vehicles for well over 30 years and have had pretty good success doing it.
 
#50 ·
small update: workshop can get a front rotors, pads and callipers and brake lines kit (mopar) for about $450-500, so ill be doing that, for the meanwhile no booster/MC update - i will get those depending on the results of the braking kit.
 
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