Please help me evaluate/solve this ABS problem. Let me preface by saying I have a tall camper shell and at least 500 lbs or more in the bed at all times. I run about 40psi in the back tires (dually)(except when towing/hvy load) and 65psi front. Tires are 255/85-16 Cooper ST's. Previous tires were Cooper AT 235's and before that the 215 factory issued Michelins. No real issues with the brakes when ABS is not activated. Computer has been corrected for tire size. (Being off as much as 10% never seemed to make a difference, just thought I'd mention it.) Driving style is pretty easy does it and is decidedly NOT aggressive.
Whenever the rear wheels break traction (the least little bit) during braking, the entire brake system goes into a lower pedal/low pressure mode and the resulting braking force becomes fairly minimal. Subjectively maybe 50%. This happens with only modest braking force and the last time, it happened on DRY pavement and nearly caused me to roll through an intersection and hit someone. Very frequent occurrences on wet roads.
This has happened from DAY ONE. The dealer indicated this is 'normal' and no problems were found. No trouble codes. And the dealer refuses to give me any ideas on how to disable the ABS, which I can understand.
Interestingly the only time the brakes have worked without the slip-skid-soft pedal was when the rear ABS sensor failed. The ABS system was totally incapacitated and I had normal brakes.
I was tempted to leave it alone. But being a stickler for keeping things correct, I fixed it. After replacing the sensor, the brake system went back to it's 'normal' operating condition.
I tried pulling the fuse for the ABS, but that kills the speedo/odo. So that's a no go. It seems obvious to me that the braking balance between front and rear needs to be more biased to the front. But of course there is no adjustment for this and I didn't want to add a control valve for fear of completely fouling up the poorly set up ABS system and possibly ending up with NO brakes at an inopportune moment.
I have had other trucks without ABS and a little skid on the rear axle was the 'indicator' to pulse the brakes. Just a little operator modulation and all is well. Never had an issue with this kind of system.
Is there a way to add a switch somewhere to turn the ABS system on/off? A TSB? Adding a flow restricting valve/orifice to the rear brake line(s) to bias towards the front?
Other ideas? Can't afford to guess on this one or experiment as equipment and family are at risk.
I'll add that I have driven several other vehicles (Pontiac, Honda, Chev, Caddy, etc) and model years with ABS and have never encountered an ABS system that acted this way.
Help please.
Linear Mode
