ABS = Will No Stop .....on dirt?

[Bob4x4]

I've had the same problems braking hard on gravel with my '04. The ABS made it impossible to stop hard. Even with the ABS help, the truck was still all over the road on the semi-loose gravel.



I have since upgraded my suspension to the Kore (DRC Race) suspension. Now, on the same roads, same places, same conditions, I have MUCH better control. The tires stay glued to the ground and I can stop much harder even before the ABS begins to take over. It stops must straighter than pre-Kore also.



I'm not saying this is a solution, but man... . Kore helped it sooo much!

I found going over 12-16" whoops at 60mph with my KORE race the ABS is not going to slow you down :-laf



Bob

 

[6 2 Carl]

Geesh and I thought I had a mechanical problem. Guess not.



So has anyone come up with a way to disconnect the ABS using a switch?

Joe

I think I am going to install a 5 amp circuit breaker instead of a switch on the ABS circuit. I am getting sick of looking at the ABS and Brake lights. The circuit breaker should allow for normal operation until the ABS is activated. As soon as more then 5 amps goes to the ABS pump the breaker will trip, disabling the pump. This should be more effective then fumbling for a switch in emergency situations.



Carl

 

[PSchwering]

The problem is Not ABS in General. The problem is that Chrysler cannot figure it out. My wife's 98 pontiac has ABS, and I would Challenge any of you to disable it, & stop faster without the ABS, in Adverse conditions. Now, there is a difference between a 7000 pound truck & a 3000 pound car - But I have driven several Chrysler cars, & they are as bad as our trucks.



The government says that to advertise as ABS equiped, the vehicle must unlock the wheels before the driver loses control. Some vehicles do this quite well, the easier way, is to release the brakes. Sure, you can't stop, but the Gov. Didn't say anything about that, Did they.



Oh well. I better quit ranting about Chrysler. I hope you all figure a way to disable them. (My 2nd gen only has Rear wheel, & I have never experienced them to work) P.

 

[Forrest Nearing]

I almost put a new pontiac into a gate when it hit a small speed bump under braking... dry pavement, PLENTY of room to stop. literally was about an inch off the gate when it finally came to a stop.



maybe the krauts have it figured out better, but I've never driven a domestic ABS equipped vehicle that actually impressed me.

 

[fox]

Soooo,, Does nobody need it, or only people with dirt for brains?



I know ALOT, and I mean ALOT of people with dirt for brains (when driving).

-------



ABS is supposed to let you steer when in a panic stop.



Yes it is, but this is a time when stopping is the most important. If I could steer around the object I don't need to stop.



ABS anti-braking system

ABS another britches soiled



The flintstones can stop quicker.

 

[Bob4x4]

I will say on the pavement the 05 abs works great,I commute in the fasttrack lane(Toll) and the only thing separating me at 70 and the stop and go traffic in the next lane is a couple yellow stripes and plastic pylons. the ABS has bailed me out a couple of times when some idiot crosses that double yellow On the other hand when I am off road using that KORE suspension for what it does best I try to remember to pull the fuse.



Bob

 

[ASchwartz]

On the other hand when I am off road using that KORE suspension for what it does best I try to remember to pull the fuse.



Bob

Bob,



You are going to have to show me that fuse in Glamis.



Avi

 

[NVR FNSH]

ABS works great in the right applications - off-road isn't one of them. Ever wonder why BMW GS motorcycles (the big psuedo-dirtbike) has a switch that allows the rider to turn off the ABS.....



Brian

 

[GaryCarter]

This is why all off-road vehicles should have an ABS defeat switch. ABS CAN GET YOU KILLED off-road.

Once on a mountain track with gravel, we nearly went over a looooooong drop because the Jeep's ABS kicked in. Only a quick grab for the parking brake saved our lives.



Gary

 

[Nate]

Remove the fuse and pull the bulbs out.

 

[rbattelle]

a "safety" switch wired in series with the abs fuse would make things easy... leave the abs working [so the dash lights are off] for normal driving, but when shat hits the fan, you flip the switch and disable the abs

This is a great idea, but you'd want to use a relay. The ABS system is probably high current.



-Ryan

 

[betterthanstock]

but you'd want to use a relay.

Hook the relay coil to the 4x4 switch on your transfer case and it will be automatically disabled in 4x4. That way you have ABS for the freeway without forgetting it turned off.

(Does ABS even work in 4x4 ? )

 

[MCrossley]

Here is the description for the ABS from the service manual:

OPERATION

Battery voltage is supplied to the CAB. The CAB performs a system initialization procedure at start up. A check of the ABS motor is performed at 15 miles per hour. Initialization consists of a static and dynamic self check of system electrical components.



The static and dynamic checks occurs at ignition start up. During the dynamic check, the CAB briefly cycles solenoids to verify operation. An audible noise may be heard during this self check. This noise should be considered normal. The ABS motor and pump are then checked at a speed of 15 mile per hour.



If an ABS component exhibits a fault during initialization, the CAB illuminates the amber warning light and registers a fault code in the microprocessor memory.



The CAB monitors wheel speed sensor inputs continuously while the vehicle is in motion. However, the CAB will not activate any ABS components as long as sensor inputs indicate normal braking.



During normal braking, the master cylinder, power booster and wheel brake units all function as they would in a vehicle without ABS. The HCU components are not activated.



The purpose of the antilock system is to prevent wheel lockup. Preventing lockup helps maintain vehicle braking action and steering control.



The antilock CAB activates the system whenever sensor signals indicate periods of wheel slip.



The antilock system prevents lockup during a wheel slip condition by modulating fluid apply pressure to the wheel brake units.



Brake fluid apply pressure is modulated according to wheel speed, degree of slip and rate of deceleration. Sensors at each front wheel convert wheel speed into electrical signals. These signals are transmitted to the CAB for processing and determination of wheel slip and deceleration rate.



The ABS system has three fluid pressure control channels. The front brakes are controlled separately and the rear brakes in tandem. A speed sensor input signal indicating a wheel slip condition activates the CAB antilock program.



There are Two solenoid valves (Isolation and Dump valve) which are used in each antilock control channel. The valves are all located within the HCU valve body and work in pairs to either increase, hold, or decrease apply pressure as needed in the individual control channels.



During an ABS stop the ISO valve is energized which acts to prevent further pressure build-up to the calipers. Then the Dump valve dumps off pressure until the wheel unlocks. This will continue until the wheels quit slipping altogether.

 

[Udaloy]

I want to answer the 4x4 question once and for all. ABS is operational while in four wheel drive. I was stuck in my brother-in-law's yard. While trying to rock myself out, I was able to get about a foot of movement. Everytime I backed up the one foot, I'd try to hit the brakes to stay put while shifting to 2nd (automatics are much better for rocking). I could never stop the truck. It would roll back forward, and lose the ground I made up. Talk about dissappointing. If someone could get the relay tied into the transfercase idea to work, I'd install that in a heart beat. ABS works fine for good conditions, just not mud or other off-road conditions.

 

[Badunit]

What I'd like to do is disable the front ABS but keep the rear. In '03 and above there is no proportioning valve. I suppose the idea is that the ABS kicks in instead of the truck trying to change the rear braking characteristics between empty and loaded conditions. Last thing I want is to swap ends during emergency braking, especially in a turn. Without the proportioning valve this is more of a possibility when empty than it was in prior years. Maybe one day I'll look into how to accomplish this front ABS defeat in the easiest manner possible. And keeping the ABS light off would be one of my goals. Pulling the fuse isn't the answer for me, though.