Good Afternoon,

My 1996 Dodge B3500 Camper Van has the parking brake light and the ABS Light on. i have had several shops try to do a scan for these codes but nothing shows up for any of them. I have a theory but i want to see what some others think. I've read some other forum posts about this similar topic, but none have solved my problem.

The Story:
A while back i drove away with my parking brake engaged and it ripped the pivot bolt for the parking brake lever in the driver side drum clean out. I think that was the first time the lights came on, but i cant be certain as it has been over 2 years since that happened and i hadn't really paid attention to it. however since then i have replaced all those parts from the point at which both parking brake cables couple into one to connect to the pedal to all the parking brake hardware in the drum itself (on the driver side only as the parking brake cable and mechanism on the passenger side seems to operate normally still), the parking brake works normally and self adjusts the rear drums properly (at least seemingly), however the lights still come on now and again, sometimes they will stay on for weeks then off for weeks, sometimes if I'm parking then moving multiple times in a day it will be on sometimes and not others. as said before no shop seems to be able to read or diagnose a problem with the brake system.

My Theory:
I have read that worn brake shoes can cause this light to come on, the brake shoes on it currently have maybe 5000 miles on them as they were replaced before the parking brake incident (i wasn't driving the van much for the past 2 years). so my guess is that worn shoes can trigger the lights to come on because of excessive travel in the brake cylinder (which was also replaced with the shoes along with all the hardware in the drums). so is it possible that worn brake drums, possible from driving with the parking brake on or from being from 1996, could cause the same lights for the same reason, excessive travel? last time i looked at the shoes they seemed to have a good amount of material on them still, and every time a shop has looked at it they've only really looked at the mechanism of the brake drum to see if anything else was damaged from the parking brake incident.

Some other evidence to support this is that it the parking brake is feeling lighter more recently now that I'm driving the van a lot more, but if i press it really hard to the floor it gets tighter then it feels right again the next time its used. so maybe the drum is worn out so the self adjuster isn't able to adjust far enough out anymore for the shoes to contact the drum, unless i push it as far as the pedal can go then it adjust a little and makes some contact? in addition to this, it does seem that the rear drums are not providing braking power and requires me to do this parking brake process to get them adjusted or climb under the rear end with a screwdriver and adjust them manually and feeling like they are working again. while i haven't been able to reliably notice when the lights come on, they do almost seem to come on when i have reduced braking power from the rear and off after I've self adjusted the brakes. but that's not a 100% reliable observation because sometimes the light comes on when i release the parking brake, other times it comes on when i release the parking brake and press the brake pedal after, and sometimes it varies from when i release the parking brake before or after i turn the vehicle on and sometimes it just comes on while driving after having been moving for a while.

Some other things i know can cause these lights are a bad rear wheel speed sensor/abs sensor (the one located in the differential on this 9.25 HD axel) and low brake fluid. i did notice the fluid was a little low, nothing scarry or anything, it just seemed like probably the rear wheel cylinders have pushed out a bit therefore holding onto more of the fluid than if everything was brand new, there are no evidence of any leaks underneath he vehicle. as for the speed sensor, i have not replaced it yet because it seems strange that it would intermittently and randomly throw the lights on, and coupled with the reduced braking power from the rear i suspect it more likely involves the actual braking system rather than the sensor.

Im planning on replacing the brake drums this week and comparing the new and old ones with measurements from a micrometer to see if there is a significant difference in material or not, at the same time i will measure the thickness off the shoe material left and compare it with my service manual and the new ones to see if they are out of spec. another note is that when i replaced these shoes previously, i replaced them with 3" shoes, at the time i did not notice any difference in width between the new and old ones, but is it even possible to put the 3" shoes on a setup that was for 2.5" shoes? this is the HD version of the axel with the 8 lugs, and i cant find anywhere that reliably can say this van should have 2.5" or 3" shoes, but the drums are meant to fit either.

Any other theories are welcome as i would really like the lights on the dash off and my rear wheel braking power restored as I'm taking this van up and down some serious hills and would like to have confidence in my brakes.

 

When did the lights first come on?

If it was shortly after you replaced a bunch of parts on the rear brakes, did you have to bleed them??

 

It's hard to say when the lights came on because I drove the van from Florida to Massachusetts after changing the brakes (and bleeding the system due to changing the wheel cylinders as well) about 2 years ago, but almost immediately after doing all the brakes is when I broke the parking brake mechanism, I cant remember if I saw the light on ever before that, but I definitely saw it on that trip to Massachusetts. On that trip I stopped at a brake shop because I didn't feel like I had rear brakes, that's where they showed me what had happened and told me they could just remove the mechanism so it wasn't rattling around in the drum, they made no mention of the fact that I would no longer have self adjusting rear brakes. So basically, from Florida to Massachusetts the brakes never self adjusted and that's when I think was the first time I saw the lights. But now the self adjusting mechanism works properly and the lights still come on randomly.

On a separate note, I think my observation stated previously was correct, I was on a long drive today and upon leaving I released the parking brake and drove for maybe 40 mins with no lights coming on and good braking power, then I stopped for about 15 mins and did not press the parking brake for that stop, when I got back in and started the van, the moment I pressed the brake pedal to shift I to drive the lights came on. Then about 15 mins later of driving I stopped and this time put the parking brake on and felt good pressure like the mechanism was working, and when I got back in 5-10 mins later and continued my drive the lights were off and did not come back on.

I also want to confirm that these drums would not self adjust under normal driving right? They only adjust with the parking brake or by braking in reverse?

 

Self adjusters should still work even without the parking brake. They *should* adjust every time you back up.... Unless they removed the arm that actually does the adjusting.....

If the lights are on because of being out of adjustment though, that should correct itself once you have them repaired.... If it doesn't, try bleeding the brakes again a bit. If the proportioning valve is out of place (which is what turns on the brake light....) that will also turn on the ABS lite.

 

yeah they removed the whole lever mechanism because the pivot bolt that holds it in along with the tensioner that pulls the adjustment lever is what sheared out of the backer plate. i have bled the breaks multiple times since then thinking that was the issue, i also had the brakes bled by a jiffy lube recently. I can try again though.

 

I was looking through some old photos of the rear brakes and i noticed that the self adjuster on both sides has about 3/4" of threads exposed at the point that i was able to slide the drum off. that seems like a bit too much and would also be another indication that the drums may be worn? I also went through all the vehicle history receipts of maintenance that i have (pretty much everything from the 118,000 mile mark, im now just over 160,000) and there is no indication that the drums have ever been replaced, so I'm changing them today regardless of its the solution to my problem because at 160,000 miles of driving all over the country and up and down serious hills and mountains, i would assume its a good point to replace the drums lol. Best case it solves the problem, worst case i have eliminated another possibility. if that doesnt solve my problem, ill bring it to a brake shop to have the brakes bled again to be 100% sure that is not the problem.

 

ok, so i know i said i would bring it somewhere and have a shop bleed the system again if the drums did not work, however, i am doing some separate work tomorrow anyway so I've had one more idea to try. i think i mentioned before that the star wheel seems to have about 3/4" of threads exposed, and this seems like to much with relatively new shoes and a new drum. so I'm thinking, maybe when i installed the new shoes and wheel cylinders, i over extended the the star wheel to start, therefor throwing off the geometry of the system because the bottom was pushed out further than the top. so now I'm thinking i will reduce the star wheel extension and reinstall the drums and press the brake pedal to expand the wheel cylinder at the top end a bit, then re adjust the star wheel to make sure the geometry is correct across the system.

i know it seems like i am hesitant to have the brakes bled, but its more of a combination of several factors including that its been bled several times already with no change, and I'm currently in an area where nobody really wants or can work on this vehicle. i cant go to most shops because its a camper and has a fiberglass top that means i need about 9.5' of clearance, and it has tanks that block the frame so i need a shop that either has an alignment rack that can support a fully loaded camper or that will jack it up on the floor (which most wont do). and of the shops I've talked to around I've had multiple quote me 2k for doing all new parts in the drum brakes if i supply the parts, so 2k for labor only. so that's why I'm trying to exhaust all options on my own first.

I will say, the new drums were certainly needed as the braking power was incredible once they were installed and adjusted, but the lights came on after stopping and re starting twice and the soft parking brake pedal and seemingly no rear brakes symptoms returned. however another symptom that maybe i didn't make clear before, it almost seems like the drums unadjusted after like 30 mins or so of driving. from what I've read they should last many miles before needing to self adjust anyway, and i need to use the parking brake every single time i park if i hope to have any rear brakes at all. otherwise it seems like there's nothing there. they shouldn't need to self adjust that much right? like they should last more and 10 miles or so?

 

The springs will just pull the shoes back to their resting position when you release the pedal, so, while readjusting isn't a bad idea, don't expect it to change anything.

Another thing that may turn those lights on, is the rear wheel speed sensor, on top of the rear diff. On your van, it's only used for the ABS, not the speedometer... that's drive from the VSS in tailhousing of the trans. I would think that if it failed though, the ABS control would set a code for it..... but, that's all in the PCM....

 

Yeah I thought of that sensor a while back, there was a range of acceptable resistance you could check through the sensor to test if it was good, I don't remember the number, but I remember testing it and it was ok. Then recently when I swapped the ring and pinion, I cleaned the area where the sensor came into the diff to rule out obstructed or dirty sensor.

 

I like to get a reading from the PCM on what the rear wheel speed sensor is telling it..... The sensor may ohm out good, but, if it give erratic readings...... that'll turn on the lite.