Brakes locking up

Moab

TJ Expert
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Dec 15, 2018
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3,154
Location
El Segundo, California
It started in the mornings. I live close to the beach. And sometimes old brakes react badly to the salt air. (It did it a bit on my '67 VW.) It seemed to revolve around the emergency brake. So I stopped using it. But even then on wet or cold mornings the brakes would grab really bad at your first few stops. The entire front end would dip as the brakes grabbed completely tight. Then after your first few stops it would adjust correctly. And you can brake slowly at a stop. These pads actually grind too sometimes. So I started thinking I have cheap bad pads.

Then it started raining this year. A few weeks ago. My son slid quite a ways in the rain and rear ended someone. And then I hit a yellow light a little late. And slid halfway thru an intersection. It appeared that the brakes locked up. Not sure what they were supposed to do in this old of a car to be honest. But there was no control. The brakes just locked up and I slid for quite a ways. If anyone had been in front me I'd have driven right into them.

Now I'm starting to think either my brakes are adjusted improperly. Or I have really shitty pads. I know shitty pads will grind and grab and sometimes squeal. These do grind and grab. But there is plenty of pad left on last inspection. I have no idea what quality they are. Also what do the rear brakes play in this? Do they brake at the same time as the fronts?

It's a stock 99' 4.0 AT Sport. 17" JK Moab wheels and stock goodyear street tires.

Do I need new brake shoes? DO they need adjusting? I know Jeep brakes are different from normal brakes and that they take extra care in adjustment. Any recommendations where to have them looked at in Socal? I'm near LAX but willing to travel for an honest expert.

@mrblaine I know I haven't sent that glovebox to you yet, I will soon. Just been busy. But I would really like your comment on this. Your the biggest brake expert I've ever known.
 
It started in the mornings. I live close to the beach. And sometimes old brakes react badly to the salt air. (It did it a bit on my '67 VW.) It seemed to revolve around the emergency brake. So I stopped using it. But even then on wet or cold mornings the brakes would grab really bad at your first few stops. The entire front end would dip as the brakes grabbed completely tight. Then after your first few stops it would adjust correctly. And you can brake slowly at a stop. These pads actually grind too sometimes. So I started thinking I have cheap bad pads.

Then it started raining this year. A few weeks ago. My son slid quite a ways in the rain and rear ended someone. And then I hit a yellow light a little late. And slid halfway thru an intersection. It appeared that the brakes locked up. Not sure what they were supposed to do in this old of a car to be honest. But there was no control. The brakes just locked up and I slid for quite a ways. If anyone had been in front me I'd have driven right into them.

Now I'm starting to think either my brakes are adjusted improperly. Or I have really shitty pads. I know shitty pads will grind and grab and sometimes squeal. These do grind and grab. But there is plenty of pad left on last inspection. I have no idea what quality they are. Also what do the rear brakes play in this? Do they brake at the same time as the fronts?

It's a stock 99' 4.0 AT Sport. 17" JK Moab wheels and stock goodyear street tires.

Do I need new brake shoes? DO they need adjusting? I know Jeep brakes are different from normal brakes and that they take extra care in adjustment. Any recommendations where to have them looked at in Socal? I'm near LAX but willing to travel for an honest expert.

@mrblaine I know I haven't sent that glovebox to you yet, I will soon. Just been busy. But I would really like your comment on this. Your the biggest brake expert I've ever known.
You're dealing with rust on the rotors from the wet. Are the rears locking up that you can tell?
 
I tend to lean towards a scorched earth policy on brakes. I'd be inclined to replace pads, rotors and calipers, drums and shoes if so equipped (spring kit and wheel cylinders). Parts are cheap, benefit is huge. Peace of mind is priceless.
 
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You're dealing with rust on the rotors from the wet. Are the rears locking up that you can tell?

I can't tell for sure. But I wouldn't doubt it. As when they grab it feels like the whole Jeep is coming to an abrupt stop.

What's my solution? I'm almost tempted to come see you and get an in person opinion. From the Wizard himself. ;) Just not sure how long it would be before I had time to make it out that way. I was out there a few weeks ago. But didn't want to drop in on you unannounced. Or short notice anyway.
 
I can't tell for sure. But I wouldn't doubt it. As when they grab it feels like the whole Jeep is coming to an abrupt stop.

What's my solution? I'm almost tempted to come see you and get an in person opinion. From the Wizard himself. ;) Just not sure how long it would be before I had time to make it out that way. I was out there a few weeks ago. But didn't want to drop in on you unannounced. Or short notice anyway.
Try doing some fairly hard stops in a short distance as soon as you leave the house first thing. That should burn the rust off that forms overnight and get them back to a more linear response. Let me know how that goes.

If you call when you are a few blocks away, that isn't showing up unannounced. ;)
 
Some brake friction compounds absorb moisture out of the air overnight and on foggy morning when cold, and will be super aggressive for the first 1 or 2 brake applications of the day. I have Wagner Thermoquiets on my Jeep (only because it came with them and I have higher priorities to address right now) and they'll put me against the steering wheel the first time I touch them on a damp morning...after that, they're mostly useless.

Seeing as how you're close to the beach, this is likely what's occuring. Noise is not unusual in this scenario when cold.
You likely have some bargain priced pads in it...that's where I'd start to solve the overly aggressive when cold problem.

As far as the wheels locking up and skidding...This is not a modern car, it's a tractor. You likely don't have ABS, and are used to driving vehicles that are more modern and refined. You'll have to simply adjust your driving style, unless some other problem exists.

I know a few things about brakes and would be more than happy to give it a look for you and handle whatever we find wrong. I'm in Long Beach...so a shorter trip than heading up to see Blaine. If you'd like to bring it down, send me a message.
 
I had this issue too on the rear drums. They would lock up when cold and wet. I adjusted them and havent had the issue in over 6 months now, even in the wet winter we're having.
 
The salt air is terrible for metal components and damp air is bad too. Put them together.....
Any time one of my machines sits for a while I try to drag my brakes a bit first thing. This warms them up to get the moisture out of the pads and also clears off any rust that may have formed. It could be as simple as putting better pads/rotors on. Also check the slider pins for condition. If they show any binding that wet salt air could effect them too. Also, while this may not help, flush out the brake fluid. If you have some chunky, sludgy fluid in there it may cause the caliper pistons to bind up. When I first got my TJ they claimed to have put all new brakes in. What they actually did was just shove new pads in. Within 50 miles 3 rotors locked up, 1 would drag without clamping harder. Luckily it happened in front of a repair shop. Cause: filthy, and I mean chunky brake fluid. Jammed up the rotors.

Also, these brake systems are absolutely nothing like a tractor. Absolutely and totally different. Not at all similar. Don't even have the same number of pedals. And only gets more different from there.
 
Also, these brake systems are absolutely nothing like a tractor. Absolutely and totally different. Not at all similar. Don't even have the same number of pedals. And only gets more different from there.

I was more referring to the wrangler as a whole...compared to say, a BMW in terms of chassis tuning and brake refinement
 
As far as chassis tuning... a tractor has NONE. No springs. No shocks. No links. No anything. It has an axle shaft sticking out from both sides of the transmission that the rims are bolted to. The front is located by a pivot point in the front bolster.

A tractor has no brake located at the end of an axle. It has no front brake at all. It has no separate hydraulic system for the brakes. It has independent pedals for each side. They are either straight mechanical linkage or a wet brake system located in the rear end and powered by either the transmission or an internal hydraulic pump.

I fail to understand why people keep saying a Jeep is more like a tractor than a ... It is simply not true. Even a Ford model T is more similar to a ... than it is to a tractor.
 
As far as chassis tuning... a tractor has NONE. No springs. No shocks. No links. No anything. It has an axle shaft sticking out from both sides of the transmission that the rims are bolted to. The front is located by a pivot point in the front bolster.

A tractor has no brake located at the end of an axle. It has no front brake at all. It has no separate hydraulic system for the brakes. It has independent pedals for each side. They are either straight mechanical linkage or a wet brake system located in the rear end and powered by either the transmission or an internal hydraulic pump.

I fail to understand why people keep saying a Jeep is more like a tractor than a ... It is simply not true. Even a Ford model T is more similar to a ... than it is to a tractor.
His point was that the mechanicals of the TJ are primitive at best. He fully understands how tractors, TJ's, Beemers, and many other vehicles are set up and his tractor analogy was merely meant to construe the lack of any sophistication present in the TJ or any of its mechanical bits. I fully agree with him especially when it comes to the brakes. Seriously Jeep? You used the same caliper that has been in use since 1990 and when you made the TJ Unlimited you changed nothing even though the rig is longer, heavier and has a higher towing capacity? You toss a 4-1 ratio t-case in the Rubis that will easily drive through the brakes offroad and it didn't occur to you to at least toss on a saddle mount caliper? If not tractor then most assuredly tractor mentality.
 
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Also not mentioned is tire pressure...if you have it set to the MAX sidewall rating of 45psi or so, the tires won't grip the road very well. Set them to around 28psi.
 
The braking system is quiet possibly the thing most different between a Jeep and a tractor.
Having worked on both tractors and road vehicles for over 4 decades and actually living on a farm all my life I can say with absolute certainty that the brakes on a TJ are absolutely nothing like a tractor other than both systems are made to slow and stop the machine.
 
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And I ask what is the particular resemblance that is more similar to a tractor than to any Italian car?
 
I had a slightly similar issue a few months ago. On brand new rear components all around and front pads/rotors, I was locking up my front passenger wheel much too easily. I ended up replacing the front calipers and brake hoses after flushing the fluid. I think that the hoses had begun to break down and send some junk into the calipers that wasn't letting the pistons retract fully.

Remanufactured calipers and new hoses are cheap
 
I have to think you have never actually worked on farm machinery before. If you had you would know just how vastly different they are. After WWII they tried to market the Jeep as a farm capable machine. Added 3 pt hitch, PTO, even remotes. And it failed. You know why? Because even those original Jeeps are nothing like a tractor.

And I believe it was Mr. Fararri himself that stated the Jeep is the only American sportscar. He would probably know better than anyone if the Jeep was more like a tractor than his cars. Yet he thought just the opposite.