2019 was a very challenging year, in many ways. One of the most exasperating issues I had to deal with was the brakes on the QuadCab. A random ABS warning light was first noticed while borrowing this truck for a few weeks in 2015, but once I started driving the truck regularly in late 2018, the ABS light became more frequent and longer lasting. The truck passed the annual safety inspection in February as the ABS light did not come on during road testing, but by late March, the ABS light became a daily occurrence. It was about this time that a heavy trailer was pulled that required setting the trailer brake controller, and while pulling this trailer through stop-n-go traffic, a delayed release in trailer brakes was felt in the truck and observed on the controller. In April, the original master cylinder began leaking internally, and its defective replacement started an almost weekly trip to local parts stores, dealing with even more defective remanufactured parts.
Replacement Remanufactured Component Defects Observed
Master Cylinder: Original unit began leaking internally at 200k. OR replacement unit had a spongy pedal that could not be corrected after 20 bleeding attempts over 4 weeks and was replaced under warranty.
HydroBoost: Original unit began leaking PS fluid into cab at 170k; OR replacement worked up to about 200k. OR units 2-6 would fail pressure test after bleeding, causing brake pedal to not spring back after being released. AA replacement delivered was wrong application; followup delivered replacement had Schrader valve installed to psi canister and was returned. AZ unit lasted for 4 months with gradually degrading performance until ultimately failing by not releasing brakes after hard braking, hissing loudly under dash, then releasing brakes. Pedal return travel would take 3-10 seconds; ABS warning light would illuminate. NAPA replacement worked immediately, and in sub-freezing weather.
Steering Gearboxes: Original unit began having choppy operation around 204k. AA replacement had a mounting lug that stripped on final torque. Replacement unit delivered had damaged input shaft and was returned. Followup replacement unit delivered had damaged output shaft seal and was returned. Second followup replacement unit delivered had slightly damaged output shaft that was corrected with careful filing.
Front Calipers: Original RF caliper not retracting fully, LF dragging at 206k. AA replacement units had loose bushings; NAPA LF replacement worked; RF replacement leaked at bleeder screw and was replaced under warranty.
Rear Calipers: Original calipers dragging at 206k. AA (2), OR (2) & AZ (4) replacement units had very loose bushings; AA RR casting cracked at bleeder screw; OR RR casting leaked at hose; NAPA RR replacement leaked at bleeder screw and was replaced under warranty.
Remanufactured Caliper Failure Summary
The BR-series 2500 HD brake calipers are a floating caliper design, with bushings bolted to the caliper adapter that is bolted to the spindles up front and Dana 80 axle in the rear. The caliper has a rubber boot that encapsulates the bushing, requiring a rubber-compatible lubricant to be applied inside the boot and onto the bushing mounting bolts. This style of 4-wheel disc brake system was used from late 1998 through early 2004; subsequent brake systems grew in size to match growing rim sizes. Earlier disc/drum combination systems used similar components, but certain components (such as hydroboost, prop.valve, and ABS HCU) are not really compatible.
Remanufactured calipers varied in quality, with evidence of pitting and scarring on pistons. Advance Auto and O’Reilly calipers were packaged in the same box, with the only difference in labeling of Wearever and Brake Best. AutoZone calipers (with and without brackets) were packaged slightly different, but of similar quality. None of these castings had any coatings, so clean grey castings at the store quickly rusted in the humid TX air.
Bushings were visibly wobbly in their bores, suggesting that the castings had too much material removed during core cleanup. This could lead to the caliper not aligning properly on the bracket, causing a ratcheting action during brake release. Similarly, excessive boring could be causing pistons to wedge themselves in their bores during brake release. This was somewhat confirmed during caliper removal after road testing, when pistons were difficult to compress in their bores, then suddenly compressed smoothly. The cumulative effect was rear brakes that would not release after braking downhill in reverse without having to throttle-rock the truck. Also, an ABS warning light would illuminate when one of the sticking pistons would fully release at random times (sometimes while flying down the highway), causing a pressure spike at the ABS pressure sensor in the proportioning valve.
By contrast, NAPA bracketed calipers had much cleaner, blemish-free pistons, and the bushings moved smoothly in their bores with practically no play observed. Castings had been painted black, so they would not rust right away like the unpainted Advance Auto, O’Reilly and AutoZone units. Cost was about 10% more than the competitors’ defective units that were all returned under warranty. NAPA calipers were not perfect, however, as a RF and a RR caliper were found to be seeping at the bleeder screws. Replacement units ordered seemed to be working as required.
The irony here is that all units were found to be remanufactured by Cardone. The NAPA units had documentation from Cardone, whereas the associates at the other stores said that the units were rebuilt by Cardone and information on the internet seemed to confirm this.
I did not attempt to measure any IDs or ODs as I had no specifications to measure against and I was trying to make repairs quickly as this was the only vehicle I had available for 2019. With the exception of the 4 caliper castings that leaked, all calipers worked well during brake application but not during brake release. Since the brakes need to be cycled rapidly for the ABS to work, the poor brake release would register as a pressure fluctuation outside of accepted parameters and set a fault code in the ABS module, which would cause the random ABS warning light. This failure mode is not directly outlined in the factory shop manual, but several symptoms of poor brake release are outlined as failure modes of other components, such as the ABS wheel sensors, the HydroBoost assembly, brake hoses, even the power steering pump and hoses.
Root Cause Analysis
This truck was driven and maintained regularly for its first 150k miles, then effectively parked in a barn for 10 years, driven occasionally to perform short-trip chores. Even though the brake system still functioned as needed, the gradual performance degradation went unnoticed as the truck was driven so infrequently and still passed annual safety inspections. But the random ABS warning light that started in 2015 became a daily occurrence as the truck began being driven daily in 2019. Each month, a new symptom would crop up, and consulting the FSM would yield a different repair for each symptom.
As more original components had been replaced, I noticed a paragraph in the FSM that covered quality of brake fluid in the ABS. Aging brake fluid begins to break down rubber components in the ABS, turning the brake fluid practically black as the rubber debris saturates the fluid. This causes brake hoses to weaken and seals to break down. The FSM recommends replacement of ALL components that have any rubber when the system becomes contaminated, which is everything in the brake system except the hard lines and ABS control module. Reviewing this truck’s service records, the brake fluid had not been flushed in over 10 years, so that old dark brake fluid finally caused the whole brake system to bite the dust.
Total brake overhaul time probably should take less than 40 hours, but chasing phantom symptoms and dealing with defective parts caused me to spend 155 hours overhauling the system. Countless hours of research were spent trying to solve this random ABS warning light problem by studying the FSM and doing research online, as well as all of the time spent dealing with defect returns.
Back on Track
After months of second-guessing and setbacks, gallons of brake fluid and power steering fluid (bought 32 ounces at a time), 3 ruined tires, 3 mildly flat-spotted tires, and way too much time spent reading about similar (but not the same) problems on various Dodge Ram 2nd Gen online forums, I finally got the brakes to function as they should, without leaks and with a firm and responsive brake pedal. This work was completed during unseasonal near-80° February weather, the day before a sub-freezing cold snap blew into the area. Test driving in the cold weather showed the brake pedal returned just as fast as it did in balmy weather. I could even tap the brake pedal rapidly to make the brake lights flash to alert following drivers, something I had not been able to do for years, which I had just chalked up to “oh it’s an old truck, it just doesn’t work that way I guess”. So the next day, I headed to the inspection station and the truck passed…a HUGE relief…
I learned that aging ABS components have to be kept in tip-top shape in order to work properly. Just because the brakes “work” doesn’t mean they are working as they should…hence the random ABS warning light. Flushing the brake fluid periodically is paramount; deferring this maintenance can be an expensive headache in the long run. But above all, knowing how systems work can help determine what problems need to be addressed, especially if defective replacement parts are thrown into the mix. This requires patience and perseverance, much the same as with a decades-old buggy. As I told several of the auto parts store associates, I’m accustomed to ordering stuff and waiting a few days before I can do the repair…each different associate would look at me with some surprise at my statement, apparently patience is something they don’t see much these days in our everything-is-on-my-smart-phone society.
Another issue of note is brake caliper lubrication. Sil-Glyde is a silicone lubricant that is recommended for all brake components, including the rubber boots that encase the slide pin bushings. Permatex Disc Brake Lubricant specifically mentions that it is only to be used on metal-to-metal applications. Internet research found that several other disc brake lubricants that did not specify if they could be used on rubber components would actually cause rubber to swell, causing binding of the caliper on the slide pins. Oddly enough, Permatex and Raybestos training videos do not mention this issue, but Wagner does differentiate between metal-to-metal and metal-to-rubber lubricants. Following their instructions, the NAPA caliper bushings were lubricated, as well as the brackets for the spring clips, the contact points of the brake pads to the spring clips, and the brake pad back plates where they contacted the calipers. Most of these areas see very little movement, if any, but presumably the lubricant is to displace moisture to reduce metal oxidation at contact points, which degrades brake performance over time.
I do not think I could have tackled this complicated brake problem on a truck that is 6 years shy from being classified as a Classic by TX DMV if I had not run into similar hard-to-diagnose problems on much older machines. As with most multi-component systems, each component has a certain operating envelope it can function within for the system to be robust. When multiple components operate outside their respective envelopes, diagnosing the problem area can be difficult as the phantom symptoms produced confuse the issue.
The toughest issue to deal with was the defective remanufactured parts, as reman’d parts seemed to be the best available cost-effective means to deal with the declining brake performance. When buying these reman’d parts, the assumption is that they have been sold as meeting specifications required. Since these specifications are not available to the general public, trial-and-error was used to determine which parts were actually as advertised. And even then, it is assumed that this will be sufficient as the system is operating apparently as required, but not known entirely for sure if it is or not.
So I reckon if that barn find has been parked for 10 years or 50 years, ya need to check them brakes and plan on just changing everything out, maybe even the hard lines…otherwise, you’re gonna spend a TON of time chasing down problems piecemeal and spend a fortune doing it…ain’t nobody got time for that