Cant lock up brakes

[bjoneill]

I’ve had my 2003 TJ Rubi for about 3 years now. I’ve just now started working on upgrading, after developing death wobble.
it came with an OME 2+ inch lift, plus some spacers.
So I went through the steering and brakes and replaced power steering hoses while it was up. Death wobble is completely gone. Using how to from this forum I aligned it and it tracks straight and true.
However, I can’t get the brakes to lock up. It stops straight, and strong. The pedal is firm. Not rock hard, but firm and not spongy.
The brake upgrade was a new Dorman M/C, all 4 discs and calipers and SS lines to each corner.
I bench bled the M/C before installing it. There is zero air in the system, rebled twice, both pressure and vacuum. There are no discernible leaks anywhere. Seated the pads per the manufacturers instructions. Although I barely smelled them heating up. Ambient temps were in the low 30s
I have 32s on 16” wheels. Could they have enough mass to prevent lockup?
It does not have ABS. Right now with some snow and ice the “softer” brakes aren’t a problem.
Any advice or help is greatly appreciated.
sorry for the long first post.

 

[mrblaine]

I’ve had my 2003 TJ Rubi for about 3 years now. I’ve just now started working on upgrading, after developing death wobble.
it came with an OME 2+ inch lift, plus some spacers.
So I went through the steering and brakes and replaced power steering hoses while it was up. Death wobble is completely gone. Using how to from this forum I aligned it and it tracks straight and true.
However, I can’t get the brakes to lock up. It stops straight, and strong. The pedal is firm. Not rock hard, but firm and not spongy.
The brake upgrade was a new Dorman M/C, all 4 discs and calipers and SS lines to each corner.
I bench bled the M/C before installing it. There is zero air in the system, rebled twice, both pressure and vacuum. There are no discernible leaks anywhere. Seated the pads per the manufacturers instructions. Although I barely smelled them heating up. Ambient temps were in the low 30s
I have 32s on 16” wheels. Could they have enough mass to prevent lockup?
It does not have ABS. Right now with some snow and ice the “softer” brakes aren’t a problem.
Any advice or help is greatly appreciated.
sorry for the long first post.

Which Dorman master did you use?
What brake pads are on the front?

 

[bjoneill]

The brake pads are Power Stop Z23, carbon fiber ceramic.
The m/c is # M390378

 

[mrblaine]

The brake pads are Power Stop Z23, carbon fiber ceramic.
The m/c is # M390378

Common issue with those pads but they should still be able to lock up 32's. The master is correct so that isn't it.

 

[bjoneill]

Is there a 2nd chance at bedding the pads?
Or does it take time?
Instructions say 5 hard stops from 40-10, followed by 5 medium stops from 35-5, then 5 min cool down.
There was more grip during the last hard stop. The last medium stop felt like the brakes faded.

 

[mrblaine]

Is there a 2nd chance at bedding the pads?
Or does it take time?
Instructions say 5 hard stops from 40-10, followed by 5 medium stops from 35-5, then 5 min cool down.
There was more grip during the last hard stop. The last medium stop felt like the brakes faded.

Go do the break in again. Repeat with a longer cool down while driving around. Our pads respond much better to longer cool downs and much hotter heat cycles. Not saying those do.

 

[motomick76]

Following as I have the BMB 16" with 315-70-17, seated per instructions, and having same issue as @bjoneill

 

[bjoneill]

I’ll try that this weekend with (slightly) higher ambient temps.
Hopefully this wouldn’t be an issue, but I did buy the calipers a couple years ago. They were stored in their original bags a boxes. Never opened. They were also from Power stop.
Thanks for your help.

 

[bjoneill]

Update, bedded in the brakes again, maybe twice, and now the brakes are GREAT!!

Thanks @mrblaine