Weird problem after new brake install

[Blade]

Hi Everyone,
I got to doing some PM on my jeep, it's an 03 Sahara, 160k on odometer, so been replacing and upgrading parts.
I replaced the rear drums & shoes, naturally I also replaced the front rotors and pads. After doing so, my front brakes developed a weird pulsation when they are hot, I say that because when they are cold, no pulsation. So I figured I'd go and upgrade the rotors to drilled/slotted and ceramic pads. Well the problem is still there. Once brakes go up in temp, as I'm coming to a stop, I still get a weird pulsation. If I brake hard as I'm coming to a stop, no pulsating effect.

Has anyone experienced this after changing/upgrading front brakes and rotors?


I have already replaced/upgraded the following;

Tie Rods
Drive axle u joints
Hub bearings
Front brake lines
Front brake calipers & pads
Track bar

 

[Chris]

@mrblaine is the TJ brake expert through and through. There's no single guy out there that knows more about TJ brakes than he does. That being said, hopefully he'll come along and offer some better advice than I can give on this subject.

First and foremost, does your TJ have ABS or not? Second of all, was this issue present before replacing the pads and rotors, or was it only present after you replaced them?

If the problem only happened after you replaced the pads and rotors, then it's very likely something to do with them. In fact, if you bought cheap Chinese pads and rotors, then there's a very reasonable possibility one of them could be slightly warped. In fact, I'd almost bet on it. Those cheap Chinese pads and rotors you get at AutoZone / eBay and other places are just complete garbage.

I'm not going to go into how big of a waste of money slotted / drilled rotors are, I'll save that rant for someone else

 

[Blade]

Hey Chris!
No ABS on my TJ and no the issue was not there prior to me messing with them. Yea, I know, I broke my own rule, if it ain't broke don't fix it, but I'm getting the TJ ready for my teen.
And yes, the first set of rotors I bought at Advance Auto, so it's possible they were the Chinese junk, so I bought the ones I have installed now from a company out of Canada, Max Advance Brakes, through Amazon. They seem to be really well made, but that doesn't always mean that they are good.

 

[Jerry Bransford]

Did the pulsation start immediately on your first test drive after the new rotors? Pulsations like that are often/usually caused by poor braking technique which can cause a build-up of brake pad material which builds up in much the same way that dirt roads build up ridges on them to create a washboard effect. Doing "limousine stops" where the brake pedal is let up on before coming to a stop helps and not holding your foot hard on the brake pedal while stopped helps too.

Also, the slotted/drilled rotors were not an upgrade, you'd be better off with just plain good quality cast rotors like from Centech. All the holes & slots do is decrease the swept brake surface area. Racers started to include those "look cool" slots & holes to help cool red-hot brake rotors, I doubt you're braking hard enough to get them red hot.

 

[mrblaine]

Hi Everyone,
I got to doing some PM on my jeep, it's an 03 Sahara, 160k on odometer, so been replacing and upgrading parts.
I replaced the rear drums & shoes, naturally I also replaced the front rotors and pads. After doing so, my front brakes developed a weird pulsation when they are hot, I say that because when they are cold, no pulsation. So I figured I'd go and upgrade the rotors to drilled/slotted and ceramic pads. Well the problem is still there. Once brakes go up in temp, as I'm coming to a stop, I still get a weird pulsation. If I brake hard as I'm coming to a stop, no pulsating effect.

Has anyone experienced this after changing/upgrading front brakes and rotors?


I have already replaced/upgraded the following;

Tie Rods
Drive axle u joints
Hub bearings
Front brake lines
Front brake calipers & pads
Track bar

If you changed the fronts twice and the problem still exists, it probably ain't the fronts. I'd start with the back drums and go from there.

 

[Blade]

Ok, I also changed the rear brakes and drums, also from advance auto.
I'll check them out and see what I find.
Thanks Blaine!

 

[mrblaine]

Ok, I also changed the rear brakes and drums, also from advance auto.
I'll check them out and see what I find.
Thanks Blaine!

Yes, you said that in your first post. There is just about no part I trust from Autozone and others of similar ilk when it comes to brakes with only a few exceptions and especially drums. Drums nowadays are very hard to get correct and the cheaper they are, the less likely they are to be correct. Occasionally we will have supply issues and as such have explored other brands for drums. I've not seen one yet that I would bolt onto anything I own much less sell to anyone.

Jump on Amazon, Rock Auto, Autoplicity etc. and find yourself some Premium Centric drums. I suspect that will resolve the issue and if it doesn't, at least you know you have a quality part.

 

[Blade]

Awesome!
I'll do that as I have no confidence in my rear brakes performance right now. I've adjustment them at least twice now and they feel like they are helping for a couple of days and soon after it just feels like the fronts are doing all the work again.
Thanks for the tip!

 

[Chris]

It is possible one of the rotors or drums is slightly warped too. I know they are brand new, but the quality control on those auto part store brands is less than stellar. If that was the case I assume they have a warranty on them and you could easily exchange them.

 

[Jerry Bransford]

... soon after it just feels like the fronts are doing all the work again.

The rear brake provide a very small percentage of the braking, the front brakes do indeed provide the vast majority of the braking power. If there was a 50:50 split of braking to the front & rear brakes, your rear brakes would be locking up all the time which causes skids and sometimes even worse. The f/r split via the brake proportioning valve is set to somewhere around 80/20.

This is due to weight transfer from the rear towards the front that takes place during braking. That shifts weight off of the rear tires and onto the front tires which is why the rear brakes would lock up too easily during a hard stop.

 

[Blade]

Alright, so I finally had a chance to check on the rear brakes this morning...mrblaine looks like you called it, the fronts were not the issue.

1. When I pulled the drums, there was a crazy amount of brake dust, I poured it out of the drums and cleaned the brake shoes also. I'd never seen that much brake dust before, it was crazy.

2. RR wheel cylinder was leaking, so I will be replacing both.

3. LR drum had a deep groove, but not the brake shoes, they looked fine.

I've ordered 2 new drums and a set of ceramic brake shoes. Drove the TJ all day and had no pulsating/skipping at all.

Thanks to everyone for your help!

 

[Chris]

Good to hear you got it solved. Those rear drum brakes can do that!

 

[Moparornocar]

I

Alright, so I finally had a chance to check on the rear brakes this morning...mrblaine looks like you called it, the fronts were not the issue.

1. When I pulled the drums, there was a crazy amount of brake dust, I poured it out of the drums and cleaned the brake shoes also. I'd never seen that much brake dust before, it was crazy.

2. RR wheel cylinder was leaking, so I will be replacing both.

3. LR drum had a deep groove, but not the brake shoes, they looked fine.

I've ordered 2 new drums and a set of ceramic brake shoes. Drove the TJ all day and had no pulsating/skipping at all.

Thanks to everyone for your help!

I'm super late lol but what happened?