Break help 2001 Grand Caravan Sport
#21
07-04-2013, 04:08 PM
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Feels like its coming from the drivers side front only. I started out changing the pads, then came the shaking....they wore down to nothing on drivers side within 2 months. So at that point I changed the rotor and pads on the drivers side. Still shakes....figured it was the caliper...changed it.....no dice. Now in the shop with this news.
#22
07-04-2013, 04:32 PM
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Feels like its coming from the drivers side front only. I started out changing the pads, then came the shaking....they wore down to nothing on drivers side within 2 months. So at that point I changed the rotor and pads on the drivers side. Still shakes....figured it was the caliper...changed it.....no dice. Now in the shop with this news.
Sorta rambling now, sorry
#23
07-04-2013, 04:42 PM
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Here is a description of how the ABS system works:
When brakes are applied with normal to moderate pressure, brake fluid is routed from master cylinder through hydraulic control unit unrestricted to wheels. During heavy braking conditions, brake fluid pressure is modulated thru HCU to individual wheels by using separate hydraulic channels for each wheel.
During an ABS stop, hydraulic pressure is controlled to all 4 wheel circuits. ABS can build r release pressure at each wheel, depending on signal generated by Wheel Speed Sensor. ABS is operational with vehicle speeds of 3-5 MPH or more.
Amber ABS warning light is controlled by CAB and/or Body Control Module (BCM). Controller Anti-Lock Brake (CAB), along with HCU, are combined in one Integrated Control unit located below master cylinder reservoir. Hydraulic pump is an integral pat of HCU. CAB controls ABS warning light by grounding circuit. BCM grounds ABS warning light when it determines that CAB cannot control light. If CAB connector is disconnected, a shorting ar in connector will illuminate ABS warning light.
When ignition is turned on(system initialization), ABS warning light is on until CAB completes its self tests. At 5-10 MPH, a dynamic check is performed. At a speed of 15 MPH, ABS will attempt to operate pump motor. If brake pedal is being depressed, pump motor test will be run at 24 MPH regardless of brake pedal position. If any component exhibits a trouble condition during system initialization or dynamic check, CAB will illuminate ABS waning light.
During an ABS stop, hydraulic pressure is controlled to all 4 wheel circuits. ABS can build r release pressure at each wheel, depending on signal generated by Wheel Speed Sensor. ABS is operational with vehicle speeds of 3-5 MPH or more.
Amber ABS warning light is controlled by CAB and/or Body Control Module (BCM). Controller Anti-Lock Brake (CAB), along with HCU, are combined in one Integrated Control unit located below master cylinder reservoir. Hydraulic pump is an integral pat of HCU. CAB controls ABS warning light by grounding circuit. BCM grounds ABS warning light when it determines that CAB cannot control light. If CAB connector is disconnected, a shorting ar in connector will illuminate ABS warning light.
When ignition is turned on(system initialization), ABS warning light is on until CAB completes its self tests. At 5-10 MPH, a dynamic check is performed. At a speed of 15 MPH, ABS will attempt to operate pump motor. If brake pedal is being depressed, pump motor test will be run at 24 MPH regardless of brake pedal position. If any component exhibits a trouble condition during system initialization or dynamic check, CAB will illuminate ABS waning light.
#24
07-04-2013, 04:49 PM
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#25
07-04-2013, 04:56 PM
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When you changed the caliper, pads, etc, there were 2 bolts that hold the caliper in. These bolts are designed to let the caliper "float" or slide and are typically referred to as caliper slide bolts or slide pins. It's a best practice to lubricate them to ensure the caliper floats properly. I have abnormal wear patterns on my passenger front brake pads because the caliper was not sliding properly. My inboard pad has worn more than my outboard (i think, cant remember now, I looked at em a couple weeks ago while doing balljoint/tie rod.)
#26
07-04-2013, 05:19 PM
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http://www.aa1car.com/library/abs_teves_mk20.htm
This link explains in better detail how the teves mark 20 abs system functions. It does appear the pump generates additional hydraulic pressure for the front brakes, however I wonder how much extra pressure it really generates.
This link explains in better detail how the teves mark 20 abs system functions. It does appear the pump generates additional hydraulic pressure for the front brakes, however I wonder how much extra pressure it really generates.
#27
07-04-2013, 06:03 PM
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#28
07-04-2013, 06:40 PM
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http://forums.anandtech.com/archive/.../t-269211.html
The only reason I bring up the slide pins and checking/lubricating them is because this is something that is a pretty easy/cheap/free task for you to try. I certainly wouldn't rule out something being afoot w/ the ABS system, since you're getting an ABS light. However, I'm personally skeptical of the pad wear being caused by ABS fault.
That being said, I'm not there looking at the van, just a keyboard commando :-/, lol
#29
07-04-2013, 07:40 PM
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#30
07-04-2013, 08:39 PM
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