Brakes feel weak?

[McCoys]

Brake Pressure is controlled by the ESC on the JL. They can tell if it off from normal parameters based on GDS info.

The test drive should provide this information but make sure the mechanic actually logs the data in a GDS while driving.

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[jeepdabest]

They sure don't build them like they used to. When I worked for General Motors as a test dummy in high speed crashes I was assigned to the 63 Chevy Impala. Feeling my head slam into the roof while eating

the steering wheel.....................it was heaven.

 

[roaniecowpony]

I bled the brakes on my 2018 at 15k miles since I had just lifted it and installed 37's. Prior, the brake pedal felt a little soft and not as firm as I thought it should be with twin piston calipers on the front. There were a lot of air bubbles in every line. After a complete flush/bleeding, the pedal was firmer and stopping was better. The pedal firmness on my 2019 is good and the 2018 is now similar to it.

That's one thing I noticed about my 18 JLUR since it was new. The pedal is mushy and will "pump up". Definitely something up. I have about 13,000 miles on mine. I should bleed them. Just haven't gotten to it. I think it's poor quality control in the assembly that allowed air into the system. If I hold my foot on the pedal, it will sink almost to the floor. You'd think they'd pay more attention to a safety system. But then they missed the minimum mark on the steering on my model year. Steering and brakes. It doesn't get much more pertinent to driving.

 

[limeade]

That's one thing I noticed about my 18 JLUR since it was new. The pedal is mushy and will "pump up". Definitely something up. I have about 13,000 miles on mine. I should bleed them. Just haven't gotten to it. I think it's poor quality control in the assembly that allowed air into the system. If I hold my foot on the pedal, it will sink almost to the floor. You'd think they'd pay more attention to a safety system. But then they missed the minimum mark on the steering on my model year. Steering and brakes. It doesn't get much more pertinent to driving.

I’ll be doing the Z36 upgrade this weekend and will bleed the system again. The only other thing which can be done at a reasonable cost is to install steel braided lines. That will be the next upgrade if I still think the pedal is a little too soft.

 

[roaniecowpony]

I’ll be doing the Z36 upgrade this weekend and will bleed the system again. The only other thing which can be done at a reasonable cost is to install steel braided lines. That will be the next upgrade if I still think the pedal is a little too soft.

I see you have what looks like Milestar 37 or 38 tires. When I put large tires on my truck, I went to a larger rotor and 6 piston Wilwoods. It really made a difference. I currently have stock BFG 33s on my JLUR and I think the stock (large) brakes are fine. But if I went to larger tires, I'd figure the cost, of at least the front brakes in an aftermarket kit, into a tire upgrade. I think aftermarket brakes are the most overlooked performance upgrade. In fact, some guys over on the truck forum I used to hang out on, wanted to argue that it wasn't a "performance" upgrade at all. LOL.

But to your point about replacing the lines, my experience is that it isn't much of an improvement. But if you're at the last few percent of braking power, definitely do it. But the effect of such a large tire really needs more brake, either by larger diameter or more clamping force. If you have gone to a PSC steering system with a pump, there's opportunity to use a hydra-boost, which will provide a huge boost in brake line pressure over vacuumn systems (definitely go to better lines with this).

 

[limeade]

I see you have what looks like Milestar 37 or 38 tires. When I put large tires on my truck, I went to a larger rotor and 6 piston Wilwoods. It really made a difference. I currently have stock BFG 33s on my JLUR and I think the stock (large) brakes are fine. But if I went to larger tires, I'd figure the cost, of at least the front brakes in an aftermarket kit, into a tire upgrade. I think aftermarket brakes are the most overlooked performance upgrade. In fact, some guys over on the truck forum I used to hang out on, wanted to argue that it wasn't a "performance" upgrade at all. LOL.

But to your point about replacing the lines, my experience is that it isn't much of an improvement. But if you're at the last few percent of braking power, definitely do it. But the effect of such a large tire really needs more brake, either by larger diameter or more clamping force. If you have gone to a PSC steering system with a pump, there's opportunity to use a hydra-boost, which will provide a huge boost in brake line pressure over vacuumn systems (definitely go to better lines with this).

I’ve just recently put 37” trail grapplers on, replacing the Pats. Due to the TG’s weighing more, the braking performance has gone down. I thought the brakes were fine with the Pats though.

If the budget was unlimited, I’d have went with Alcon pads, calipers, and rotors.......maybe next year.

I agree on the brake lines, shouldn’t be a huge improvement, just hoping they would firm up pedal pressure some.

In no way am I ready to do a PSC hydraulic steering system though. However, having hydro boost brakes would be great. I had those on an off road 77 Chevy truck and they were excellent.

 

[blnewt]

When I put large tires on my truck, I went to a larger rotor and 6 piston Wilwoods. It really made a difference.

I have a 4pot Wilwood set on my Infiniti, nice upgrade for sure

This new 6pot front set for the JL would be badass! Only buzzkill is it says 18" wheels maybe req'd
https://www.wilwood.com/BrakeKits/BrakeKitsProdFront?itemno=140-15892

 

[limeade]

I have a 4pot Wilwood set on my Infiniti, nice upgrade for sure

This new 6pot front set for the JL would be badass! Only buzzkill is it says 18" wheels maybe req'd
https://www.wilwood.com/BrakeKits/BrakeKitsProdFront?itemno=140-15892

That’s a nice kit and not too expensive. Yeah, not thrilled about 18’s “maybe” fitting. But definitely a no go if it requires 20’s.

 

[blnewt]

That’s a nice kit and not too expensive. Yeah, not thrilled about 18’s “maybe” fitting. But definitely a no go if it requires 20’s.

At least they have that clearance diagram, so maybe some time measuring against your current wheels you'd at least have an idea how tight they'd be???
https://www.wilwood.com/Images/BrakeKits/WCD_Drawings/WCD_dwg-Large/ds1364_wcd-lg.jpg

 

[roaniecowpony]

I’ve just recently put 37” trail grapplers on, replacing the Pats. Due to the TG’s weighing more, the braking performance has gone down. ....

At least they have that clearance diagram, so maybe some time measuring against your current wheels you'd at least have an idea how tight they'd be???
https://www.wilwood.com/Images/BrakeKits/WCD_Drawings/WCD_dwg-Large/ds1364_wcd-lg.jpg

I looked at my spare on my JLUR with stock wheels. The inside is a bit over 15". Maybe 15 1/2" max. So it looks like 18"s are needed.

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