Article Archive Details
Hendon Publishing

MSP-NIJ Aftermarket Brake Pad Tests

The last man standing. That is what Raybestos was after just the first phase of the MSP-NIJ tests of police replacement brake pads—before any of the pads even made it to the race track.

When it was all over, Affinia-Raybestos proved their long-standing claim that their aftermarket brake pads are as good as Original Equipment (OE) brake pads…and no one else is even close.

In mid-2010, the Michigan State Police conducted a series of tests on aftermarket replacement brake pads for all four pursuit-rated vehicles: Ford CVPI, Dodge Charger Pursuit, Chevy Impala 9C1 and Chevy Tahoe PPV. This brake test was funded by the NIJ’s National Law Enforcement and Corrections Technology Center, NLECTC. The complete evaluation is available online.

The testing was conducted in two stages. In Stage 1, the various brands of brake pads underwent lab testing to verify their compliance with Federal Motor Vehicle Safety Standards (FMVSS). This is the standard the OE brake pads must meet. In Stage 2, the pads that passed the FMVSS standard were installed on all four police vehicles. Then each vehicle performed both 60 mph stops and 125 mph stops at Chrysler’s Chelsea Proving Grounds. Each vehicle was also timed around the 2-mile Grattan Raceway Park road course.

Pre-Qualify to FMVSS

Stage 1 began with an open invitation to any company with a U.S. or Canadian business addresses who has experience with high performance brakes to submit samples for testing. The MSP specifically solicited brake pads from 28 different manufacturers who offered “severe duty” brakes for police vehicles. This stage was a lab test using a dual dynamometer that tested compliance against FMVSS Standard 135. This was a brilliant first step.

The MSP Brake Effectiveness Test, based on FMVSS 135 braking performance standards for new motor vehicles, as well as OE requirements for police-pursuit rated vehicles. This lab test answered the question “Do these brake pads even belong on a police vehicle?” It is one thing to be aftermarket promoted as police spec pads. It is a whole other thing to pass the same brake-pad lab tests that automakers must pass.

In 1997, and again in 2000, the NIJ funded police brake pad tests conducted by retired MSP troopers involved in the annual MSP vehicle tests. However, in those evaluations, literally any pad that was marketed to the police was tested. In 2000 for example, they did on-car, on-track tests of 24 different brands of brakes.

Not so this time around. This time, the pad had to first pass the federal standard that dictates the minimum standards for brake performance, and then a high-speed component of the same standard. Why even test the brakes on a road course if it doesn’t meet those standards?

The stunning result of the Stage 1 test should be a heads-up to every police fleet manager in the nation. Most of the aftermarket police-oriented, police-labeled, police-marketed pads submitted to MSP for lab tests failed. The list of brake pads tested in Stage 1 is confidential.

Four brake pad manufacturers successfully completed the entire MSP-NIJ test protocol. Affinia-Brake Parts, Inc. makes brand name brakes like Raybestos, ACDelco, UAP-NAPA and CarQuest. This can be a bit confusing. The Raybestos brand of pad is not as widely or as easily available as the ACDelco brand of pad. However, the same exact pad is marketed under all four brand names.

Yes, ACDelco has long been associated with General Motors. No, by selecting ACDelco, you are not putting Chevy brake pads on your Dodge or Ford police vehicle. In fact, if you specify the “police” brakes in the available everywhere ACDelco line, you will be using Affinia-BPI brakes.

The other successful manufacturers included: Rayloc, a division of Genuine Parts Company, the majority parts supplier to the NAPA auto parts chain with Ultra Premium the most meaningful brand; GRI Engineering, a division of MAT Holdings and markets under the Dan Block brand; and FDP Brakes, which markets under the brand MaxStop Plus.

The original plan was for the MSP to conduct road course testing on the top three finishers in each category. Those plans changed. On the Charger and Tahoe, the Affinia-Raybestos pad was the only pad to pass Stage 1. In fact, the only brake pad manufacturer left standing with brake pads for all four police vehicles was Affinia-Raybestos.

On-Track ABS-Activated Stops

Stage 2 of the tests involved on-track tests with the four police package vehicles. The tests included ABS-activated stops from 60 mph, then ABS activated stops from 125 mph conducted on the 4.7-mile oval at Chelsea Proving Grounds.

The tests concluded with road-racing lap times around the Grattan track. For every test phase, OE brake pads were used as a control, as a benchmark, to put the aftermarket brake pads in perspective.

In all cases, the OE rotor was used in the vehicle testing. The brake pads were all matched to the rotor. The rotor and pad were burnished together using a 200-stop procedure. Of course, the on-track testing was done “blind” with the make and model of the pads not revealed until after the testing was completed.

The patrol-speed brake testing was a series of 10, ABS controlled stops from 60 mph. This was followed by a cool down period long enough for the brakes to fall below 212 deg F, which is a normal patrol-use heat level. The 10 stop sequence was then repeated and the results averaged.

The pursuit-speed brake testing was a series of six, ABS controlled stops from 125 mph. In this case, the cool down period was one lap around the 4.7-mile oval between stops. No effort was made to get the brakes below a certain temperature between high speed stops. Again, the results were averaged.

On the Charger, both the 60 mph and 125 mph results were an even tie between the OE pads and the Raybestos pads. On the Ford CVPI, the 60 mph results were an even tie between the OE, Raybestos and Rayloc pads, but the 125 mph tests opened up a gap. At the higher speeds, the Raybestos and Rayloc pads stopped a half car length shorter than the OE pads. From 125 mph, that is realistically also a tie.

On the Impala, the 60 mph results were an even tie between Raybestos, GRI Engineering and the OE pads. However, from 125 mph, the Raybestos pad held a car length advantage over the other two. On the Tahoe, in both the 60 mph and 125 mph results, the OE pads held an advantage over the Raybestos pads.

Grattan Road Course

Machine controlled tests in a lab environment and ABS-controlled, straight line stops provide valuable information. However, nothing matches the credibility of the performance on the road course where man and machine come together as one unit in a realistic testing environment. “People don’t drive dynos,” said Charles Darsey, test manager at the Affinia Research and Development.

Each vehicle, each brake pad, was driven a total of 32 laps. This driving is divided among four MSP EVOC instructors, each driving eight laps. While the average lap times were the primary measurement, each EVOC instructor also completed subjective evaluations after each eight-lap effort.

This driver evaluation included ratings from 1 (none) to 5 (most) in areas like brake fade, change in pedal feel, pedal travel, pull side-to-side, odor-smoke, noise and roughness-pulsation. The comments for all of the tested pads are posted online. These are definitely worth reviewing. Some pads got perfect and near-perfect (1 and 2) ratings, while other pads were loaded with not-so-good (4 and 5) ratings.

On the Charger, the road course results were an even tie between the OE pads and the Raybestos pads. On the Ford CVPI, the road course results were a four-way tie between the OE, Raybestos, FDP and Rayloc pads. On the Impala, the OE pads held a slight (one-half second) advantage over the Raybestos and GRI pads. On the Tahoe, the road course results were an even tie between the OE pads and the Raybestos pads.

The take-away lesson from the NIJ-sponsored tests? Caveat emptor. Just because an aftermarket company claims to provide “OE-equivalent” brake parts, doesn’t mean the parts are really OE-equivalent. Just because the local parts store has a “police” listing for an aftermarket brake pad, doesn’t mean it is up to accepted standards for pursuit performance. Some aftermarket pads match the performance of the OE police pads, but most don’t. Be careful.

National Standard for Police Brakes

The soft body armor worn by police officers is tested to a national standard. The makes and models of body armor that pass the national standard are posted on a Compliant Products List. The National Law Enforcement and Corrections Technology Center (NLECTC) coordinates a national compliance testing program conducted by independent laboratories.

The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology develops voluntary national performance standards for compliance testing to ensure that individual items of equipment are suitable for use by criminal justice agencies. The standards developed by OLES serve as performance benchmarks against which commercial equipment is measured.

Police brakes are certainly as safety-critical as body armor. Yet, these aftermarket auto parts are almost entirely without regulation, driven by market forces only. The recent round of tests proves the point. While 28 different manufacturers of “police or heavy duty” brakes were submitted, only five manufacturers got past the FMVSS federal standards.

Unlike body armor, NIJ-OLES does not need to develop a standard for police brakes. FMVSS 135 already exists—the federal standard that spells out the braking requirements for new passenger vehicles. The testing protocol for FMVSS is equally clear.

Again, this standard answers the question “Do these aftermarket brakes belong on the police vehicle in the first place?” That is, could Chevy, Dodge or Ford have sent the police vehicle from the factory with brakes that perform like these do? In 23 out of 28 cases, the answer was “no.”

Fleet managers should put “must pass FMVSS 135” on their bid requirement for brake pads. Just like body armor, if the brake pad is on the Compliant Product List, pick the low bid brakes. No further testing is necessary.

The Michigan State Police and the Los Angeles County Sheriff run brake tests as part of their annual vehicle tests. These published results are based on Original Equipment brake pads only. Every five to 10 years, depending on funding, separate brake pad tests are performed by major police departments. Police Fleet Manager conducted a series of tests in 2010.

While all these on-vehicle tests produce excellent data, in each case, many opinions are expressed and questions of protocol are raised. The high speed test should have been from 100 mph instead of 125 mph. Or, there should have been 10 stops before a heat soak-cool down instead of six.

Or, the test should have included tests to failure. That is, we never know how long a pursuit will be so keep braking from 100 mph until the brakes fade (stopping distance increases by 50 percent) even if it takes 25 stops in a row. Or, that department tests brakes oriented to heavy urban use and this department tests brakes for highway patrol use, but we are in between. Or, the police department testing the manufacturers are required to pass are so stringent the OE pad is more aggressive than necessary, which means the pads wear out sooner than necessary, i.e., brake life is shortened.

Everyone has an opinion. Standards should be independent of such individual opinions. A federal standard already exists. Optionally, a brake industry protocol exists that appears to duplicate the FMVSS in police applications, called the Dual Dynamometer Differential Effectiveness Analysis. The wheel does not need to be reinvented. The police vehicle must have OE-equivalent brake pads…and proof of that equal performance must be more than a parts catalog listing or a starburst decal on the package.

Published in Police Fleet Manager, Jul/Aug 2011

Rating : 10.0



No Comments

Related Companies

Article Images

Click to enlarge images.

Close ...