Attention: TDR Forum Junkies Guys, I had responded in 3rd Gen section, then realized the 2nd Gen guys might want to read this as well, so I've posted here as well. I hope that doesn't violate some forum rule... But here's an event you all may be interested in hearing about. S
I want to share an experience I've had with my 3500 4wd 5 spd truck this past week. As many of you know, we got hammered with snow and ice here in NC recently, and I live on a fairly steep hill, which results in dozens of stranded motorist needing help every year. I typically use my truck to pull my hotrods and chore-type work, so it sits most of the year. I pull my truck out yesterday, and tow stranded cars from in front of our subdivision just to keep the roadway clear - and because my wife had not returned from work yet (took her 4.5 hours to make a typical 20 minute commute), and that's where this story begins.
She calls to tell me she wanted to park at the top of the hill, in a Church parking lot, and for me to come pick her up, which I do. Once she's in my truck, I decide to do a low speed stab of the brake pedal just to see how the brakes react (not realizing yet that my ABS is NOT designed to function like 1500's or passenger cars). Remember, I'm on snow and ice when I jammed the pedal. The pedal went nearly to the floor, with only enough pedal left to engage the front brakes. I made it home, but dollar signs went flying across my face as I started to tally what would require fixing to restore my brakes, which had worked perfectly up until this incident.
So I come home and start scowering the blogs and find the 'off road' crowd encounters similar loss of pedal pressure/travel issues when on uneven, or loose (like gravel), surfaces, which is similar to what I experienced, and it took some digging to discover that this is NORMAL...
So I pull my factory service manual (courtesy of Geno's Garage) and began to read. Turns out, there are two distinctly different versions of ABS on our trucks. The 1500 trucks actually have a system similar to most passenger cars, in that stabbing the pedal results in pulsating the brakes to avoid a major skid. At first, I thought this was the system used on all of our trucks, but that is not the case.
If you own a 2500, 3500, or larger Dodge truck, the RWABS (rear wheel ABS) is a system designed primarily to prevent jack-knifing while under, or towing, a load. This would be the case in an emergency stop scenario where a shifting load, or heavy trailer, would try to lift (unload) the rear wheels (slippage). IF you stab the pedal on a slick surface, the ABS box interprets this just like it would for a panic stop, under a heavy load, and on a good surface. More reading...
The other thing I wasn't aware of is, under normal conditions, the ABS box diverts most of the initial fluid volume to the rear wheels first (for sensing and balance) and to engage the automatic adjusters. Remember, our ABS is designed to counter shifting loads - not routine slippage like passenger cars. I know of others who complain these adjusters don't work, but I chalk that up to a box that may not have cycled through the panic sequence, and/or not stroking enough to perform the function. I don't know that for sure, but I'll elaborate more below.
When the rear wheels start to lock up, the ABS runs a "dump" sequence that, literally, drops pressure to the rear wheel cylinders to permit a 'soft' transition while leaving front wheel braking intact. This 'dump' sequence prevents the REAR wheels from locking, and results in the pedal going nearly to the floor. This is NORMAL according to the DODGE service manual, and I can tell you; as long as you continue to drive in slippery conditions, and use 'routine' pedal pressure, your brake pedal/pressure will not restore itself. The system is designed to automatically reset, but you may need to 'coax' it...
Fast forward to today: The snow and ice are gone from most of the roads, so I decide to take a drive in the truck. I'm thoroughly PO'd as I find the pedal is still stroking near bottom, and it's a challenge to stop with just a slight stroking of the front brakes. Raising the rpm's seemed to help a little; pumping the brake pedal 3-4 times would bring it back to normal; but several seconds later pedals near the floor again. Here's what I did:
With the roads now clear of snow and ice, I drove the truck around the subdivision making repeated, normal, stops. No change. I then drove the truck up to about 30 mph, and stabbed the brake pedal. Still no change. So I repeated the process 2 more times, each time, stabbing the pedal as hard as I could. On the third hit, the brakes were completely restored. Not only were they completely restored, but I had the highest, hardest, pedal I can remember, since the truck was new, and I think this is because the
ABS and auto adjusters were jolted by my simulated panic stops. Anyway, my brakes are working excellent now, and the only thing I can assign it to is the RWABS system had not been cycled over the course of it's life, and my repeated hits on the pedal may have broken the shuttle valve loose and restored it's normal operation.
In summary, guys, if you've experienced a dropped pedal resulting from a panic event, you must get the truck on a dry surface in order to restore normal pressures and function.
While I'm not claiming this is the solution for everyone experiencing this problem, I can tell you it worked for me - and it worked today. Good luck with your brake issues and I hope this bit of feedback was beneficial.
Southernman
I want to share an experience I've had with my 3500 4wd 5 spd truck this past week. As many of you know, we got hammered with snow and ice here in NC recently, and I live on a fairly steep hill, which results in dozens of stranded motorist needing help every year. I typically use my truck to pull my hotrods and chore-type work, so it sits most of the year. I pull my truck out yesterday, and tow stranded cars from in front of our subdivision just to keep the roadway clear - and because my wife had not returned from work yet (took her 4.5 hours to make a typical 20 minute commute), and that's where this story begins.
She calls to tell me she wanted to park at the top of the hill, in a Church parking lot, and for me to come pick her up, which I do. Once she's in my truck, I decide to do a low speed stab of the brake pedal just to see how the brakes react (not realizing yet that my ABS is NOT designed to function like 1500's or passenger cars). Remember, I'm on snow and ice when I jammed the pedal. The pedal went nearly to the floor, with only enough pedal left to engage the front brakes. I made it home, but dollar signs went flying across my face as I started to tally what would require fixing to restore my brakes, which had worked perfectly up until this incident.
So I come home and start scowering the blogs and find the 'off road' crowd encounters similar loss of pedal pressure/travel issues when on uneven, or loose (like gravel), surfaces, which is similar to what I experienced, and it took some digging to discover that this is NORMAL...
So I pull my factory service manual (courtesy of Geno's Garage) and began to read. Turns out, there are two distinctly different versions of ABS on our trucks. The 1500 trucks actually have a system similar to most passenger cars, in that stabbing the pedal results in pulsating the brakes to avoid a major skid. At first, I thought this was the system used on all of our trucks, but that is not the case.
If you own a 2500, 3500, or larger Dodge truck, the RWABS (rear wheel ABS) is a system designed primarily to prevent jack-knifing while under, or towing, a load. This would be the case in an emergency stop scenario where a shifting load, or heavy trailer, would try to lift (unload) the rear wheels (slippage). IF you stab the pedal on a slick surface, the ABS box interprets this just like it would for a panic stop, under a heavy load, and on a good surface. More reading...
The other thing I wasn't aware of is, under normal conditions, the ABS box diverts most of the initial fluid volume to the rear wheels first (for sensing and balance) and to engage the automatic adjusters. Remember, our ABS is designed to counter shifting loads - not routine slippage like passenger cars. I know of others who complain these adjusters don't work, but I chalk that up to a box that may not have cycled through the panic sequence, and/or not stroking enough to perform the function. I don't know that for sure, but I'll elaborate more below.
When the rear wheels start to lock up, the ABS runs a "dump" sequence that, literally, drops pressure to the rear wheel cylinders to permit a 'soft' transition while leaving front wheel braking intact. This 'dump' sequence prevents the REAR wheels from locking, and results in the pedal going nearly to the floor. This is NORMAL according to the DODGE service manual, and I can tell you; as long as you continue to drive in slippery conditions, and use 'routine' pedal pressure, your brake pedal/pressure will not restore itself. The system is designed to automatically reset, but you may need to 'coax' it...
Fast forward to today: The snow and ice are gone from most of the roads, so I decide to take a drive in the truck. I'm thoroughly PO'd as I find the pedal is still stroking near bottom, and it's a challenge to stop with just a slight stroking of the front brakes. Raising the rpm's seemed to help a little; pumping the brake pedal 3-4 times would bring it back to normal; but several seconds later pedals near the floor again. Here's what I did:
With the roads now clear of snow and ice, I drove the truck around the subdivision making repeated, normal, stops. No change. I then drove the truck up to about 30 mph, and stabbed the brake pedal. Still no change. So I repeated the process 2 more times, each time, stabbing the pedal as hard as I could. On the third hit, the brakes were completely restored. Not only were they completely restored, but I had the highest, hardest, pedal I can remember, since the truck was new, and I think this is because the
ABS and auto adjusters were jolted by my simulated panic stops. Anyway, my brakes are working excellent now, and the only thing I can assign it to is the RWABS system had not been cycled over the course of it's life, and my repeated hits on the pedal may have broken the shuttle valve loose and restored it's normal operation.
In summary, guys, if you've experienced a dropped pedal resulting from a panic event, you must get the truck on a dry surface in order to restore normal pressures and function.
While I'm not claiming this is the solution for everyone experiencing this problem, I can tell you it worked for me - and it worked today. Good luck with your brake issues and I hope this bit of feedback was beneficial.
Southernman
