RAM BRAKES PERFORMANCE IMPROVEMENT
Tech articles, misc: http://www.pavementsucks.com/tech/
Over the past 3 weeks I have been changing out the brakes on my 1995 model year 1500 Ram Club Cab 2wd.
The original factory front pads and rear shoes were changed out on this truck back at 61,000 miles. Chrysler instruction sheet K6855323AB says these original brake parts were a "Delco 243EE" set, although the front pads had markings that said:
DM 128FE 7259/0 2/1 on the outboard pad
DM 128FE 8154 7259-1 1/1 on the inboard pad
Delco243EE**Delco243EE on rear shoes
I changed these original brake parts to 'improved' Mopar Replacements that were recommended by Dodge in 1998 to improve brake performance in 1994-BR/BE 1996 Ram Truck 1500 Series.
This was a $156 kit bought at the dealer, part number 05013447AA.
I wrote up a report to DiRT on this Thu Apr 08 07:27:13 1999.
The instruction sheet K6855323AB included with the kit says that the improved brake parts are a "Delco 224 FF" set of front pads BXH3EEE9278127E matched with special rear shoes that are indeed marked Delco224FF. These brake parts lasted on my truck from 61,000 miles to 140,000 miles, at which time the front pads still had 3/16 inch thickness, but the rear shoe thickness had worn away enough that the rivets had scored the brake drum surface.
Prior to taking off the Delco 224FF brake parts I did 5 full stops with the truck from 60 mph on a level asphalt road in dry 60-70 degree weather. I would accelerate up to 60 mph then hit the brake pedal when I felt the front tires hit an expansion joint in the road. I measured from the expansion joint to where the nose of the truck stopped with a tape measure.
"Delco 224 FF" set Results were:
Average = 214 feet
When I had Bridgestone Dueler HL 245 75 R16 tires on this truck the tire tread had so much dry traction that I could not cause the tires to skid in a panic stop from 60 mph no matter how hard or quickly I hit the pedal.
In the above 5 tests I found that with Michelin LTX MS 245 75 R16 tire tread pattern and rubber the truck would skid easily.
I have the standard Rear Wheel Anti-Lock (RWAL) system built by Kelsey Hayes, not the optional ABS system.
Much of the variation from the worst 223 feet to the best 197 foot stop, I feel was due to skidding causing me to release the pedal momentarily. Even so, I developed a flat spot on one of the rear wheels and there is now a slight vibration - or maybe the Bendix drums aren't balanced properly.
I put Bendix AF462 shoes ($32.99) on the rear
with new Bendix #140660 drums ($54)
replaced both sides star wheel adjusters:
1531/F73182S USA Brake Parts ($12)
1530/F73181S, "Made in USA"
AND REPLACED the original 1500 series 15/16 inch dia brake cylinders with 1 1/16 inch dia brake wheel cylinders [Wagner WC79767 or Raybestos WC37290 ($7.49 @ RockAuto.com), that are standard on 2500/ 3500 series Rams.
The larger wheel cylinders with their 28% greater piston area bolted right in with no modifications needed.
With just the rear shoes changed to Bendix, and wheel cylinders changed out to the larger diameter, I did 5 more 60-0 stops:
Average = 206 feet (from 215 originally)
Changed the front pads to Bendix MKD369FM ($54.39),
polished the 4 rusty caliper sliding surfaces
with a abrasive rubber wheel on a Dremel tool,
lubed these 4 surfaces with a coating of NeverSieze (the thickness of a cigarette paper),
lubed the caliper bolts and sleeves with 10 drops of "BreakFree",
flushed and bled the brake fluid using two large bottles of Valvoline SynPower Dot 3/4 brake fluid,
and then did 6 more 60-0 stops:
Average = 184 feet
On these 6 stops the brake pedal had a good 'progressive' feel that allowed me to stop with less skidding, but I think the pedal is not as firm as it should be if all the air bubbles were out of the lines. I intend to bleed the 4 brakes again.
Note: Dodge did put a different size brake bleeder fittings on the rear and the front! front bleeder a metric wrench size and the rear one is SAE.
It is possible that I am feeling more brake pedal movement because it takes 28% more brake fluid to move the larger rear cylinders the same distance.
The above numbers are not as precise as I would like, but my best guess is that these changes improved the rear brakes about 4%, and the front brakes improved about another 6%.
I can stop about 30 feet shorter now. My best two stops from 60 mph were 167 ft and 176 feet.
The best sports cars stop in 110-120 feet from 60 mph - at least according to magazine reviews.
I guess we should all leave an extra 60-70 feet between our trucks and a sports car in front of us - because they can stop shorter than we can. I have seen a lot of Rams on the road with front bumper damage indicating they could not stop in time.
3500’ FRONT CALIPERS HD: Wagner Quick Stop Front Caliper Set x2 L134353 L134354; Interchanges Cardone 164744, Dodge 30 1998 2002 Van B2500 3/4 Ton 2001 V8 318ci 5.2l 360ci 5.9l 2000 1999 Cng/fi B3500 10 Ram 2500 V6 239ci 3.9l 3500 http://www.cardone.com/English/Club/Select/default.asp
BRAKES: As far as your brake lines,
Those might be able to fit, those are the longest I could find. They are chevy, but I would assume it would be the same design. Hope it helps some. The two sites are www.classictube.com
TIRE RACK- EBC 6000 pads
The EBC 6000 Series Extra Duty disc brake pads are designed for 4x4s, pickup trucks and sport utility vehicles used for commuting, trailer towing and off-road driving. They were developed to meet the needs of light truck driving enthusiasts by offering better braking while generating significantly less brake dust than standard disc brake pads.
The EBC 6000 Series Extra Duty disc brake pads have a higher initial brake effect than most aftermarket pads to provide improved pedal response. Their non-metallic brake material does not contain steel fibers or carbon particles that we have found normally leaves dust deposited on the vehicle’s wheels. These extremely low dust disc brake pads provide up to an 80% reduction in the brake dust generated on most modern 4x4s, pickup trucks and SUVs.
As standard brake pads wear, brake dust is released as the friction material carbonizes at temperatures found in everyday braking. EBC 6000 Series Extra Duty disc brake pads are formulated to run cleaner because they resist carbonizing until over 1000° Fahrenheit, so in normal street driving, dust is almost entirely eliminated. Additionally, the EBC 6000 Series can handle the high heat loads commonly associated with trailer towing and are true premium brake pads that offer fantastic value for the money.
Features and Benefits of EBC 6000 Series Extra Duty 4x4 Truck & SUV Brake Pads:
Upgrades brake performance, improved pedal response
Excellent initial bite resulting in instant response, no warm-up needed
Fade-resistant, heat stable to a blistering 1000° F
Extremely low disc abrasion, uses man made Aramid fibers such as Kevlar or Twaron
Low dust formula, does not contain steel fibers or carbon particles
Low vibration, smooth operation
1. Do I need to follow a break-in procedure when I install new GranSport Carbon-Ceramic brake pads?
Yes.... a proper break-in of rotors and pads is crucial to ensure proper braking performance and wear characteristics of your new pads. Pads and rotors that are not properly broken in may end up creating other symptoms such as vibration or noise or the pads may end up "glazing" which could dramatically affect stopping performance. Always follow the break-in procedure described in the Break in Instructions document (Adobe PDF format).
2. Do I need to resurface existing rotors when I am installing a new set of pads?
In order to ensure a uniform mating surface between the new brake pad and existing rotor, it is optimal to resurface the rotor prior to installing and bedding-in new brake pads. Resurfacing the rotor will also help ensure maximum pad life and braking torque (i.e. stopping power). Further, when changing from one brake compound to another, especially when switching from semi-metallic brake pad to a ceramic-based brake compound, it is necessary to turn your rotors to remove any existing friction material deposits on the rotor. These friction material deposits (called "film transfer") can often interfere with the proper "bedding" of new brake pads and, additionally, can cause a notable shudder during the initial stages of new pad use.
Keep in mind, however, that when resurfacing the rotor, make sure you are within 20% of the factory specified rotor thickness after resurfacing, or else your rotor will be more prone to warping and cracking, or otherwise present a condition where catastrophic failure may occur (e.g. a rotor may crack severely and then shatter under hard braking).
3. I am experiencing a brake shudder - what is causing this?
There are three main causes of "brake shudder", which is generally felt as a brake pedal or steering wheel pulsation or vibration. Having verified that your rotors are not warped (i.e. warped rotors are another, more obvious, cause of the brake shudder phenomenon), the following are possible, commonly overlooked, explanations for an experienced brake shudder:
a. An improperly seated or mounted rotor (i.e. the rotor does not turn perfectly parallel to the brake pad surfaces). This can be due to:
• debris trapped between the backside mating surface of the rotor and the wheel hub
• improperly tightened lug nuts/bolts
• pads that are not properly re-aligning themselves after releasing the brake pedal, due to a very rough or dry (i.e. non-lubricated) brake pad to mounting clip interface.
b. Heavy friction material film transfers on the rotors. Very heavy use of the brake pads, especially use that exceeds the manufacturer's recommended heat range, can result in uneven friction material deposits on the rotors. This results in a "grab-release" effect when the brakes are applied. While this will generally even itself out over time, in extreme cases, the rotors may need to be resurfaced/turned/cut.
c. Worn suspension parts (i.e. springs, shocks/dampers, bushings, etc.). "Old timers" call this type of suspension shift under torque load "tramp". In this situation, the car's alignment is slightly changing due to brake torque upon brake pedal application. Severe cases of this result in a very notable pull in the steering, and can become evident as a shudder. If this is the cause of your brake shudder, the suspect suspension components should be replaced.
4. What is brake fade and why does it occur?
Pad fade occurs for several reasons. All friction materials have a coefficient of friction curve over temperature. Friction materials have an optimal working temperature where the coefficient of friction is the highest. Sometimes you can use the brakes so hard that you get the temperature over the point of maximum friction to where the coefficient of friction curve starts to decline.
The mechanics of this decline in the coefficient of friction are varied. At a certain temperature, certain elements of the pad can melt or smear causing a lubrication effect, this is the classic glazed pad. Usually the organic binder resin starts to go first, then even the metallic elements of the friction material can start to melt. At really high temperatures the friction material starts to vaporize and the pad can sort of hydroplane on a boundary layer of vaporized metal and friction material which acts like a lubricant. Pad fade is felt as a car that still has a decent, non mushy feeling brake pedal that won't stop even if you are pushing as hard as you can. Usually it builds somewhat slowly giving you time to compensate for it, but some friction materials have a sudden drop off of friction when the heat is put on them resulting in sudden dangerous fade.
Green Fade Green fade is a type of fade that manifests itself on brand new brake pads. Brake pads are usually made of different types of heat resistant materials bound together with a phenolic resin binder. These are thermosetting plastic resins with a high heat resistance. On a new brake pad, these resins will out-gas or cure when used hard on their first few heat cycles. The new pad can hydroplane on this layer of excreted gas. Green fade is dangerous because many people assume that new brakes are perfect and can be used hard right off the bat. Green fade typically will occur much earlier than normal fade so it can catch a driver that is used to a certain car's characteristics unaware. Typically the onset of green fade is rather sudden, further increasing the danger factor. Green fade can occur if you change the pads and drive on the street for a few hundred or even thousand miles, never braking hard, then suddenly start using the brakes hard.
5. What do edge codes mean?
An edge code is a means of identification that may be used to describe the initial frictional characteristic of any brake lining.
Typically, a two-character code (e.g. EE, FF, GG, HH, etc) is used on specific friction formulation. These characters represent the coefficient of friction when a 1" square piece of friction material is subjected to varying conditions of load, temperature, pressure and rubbing speed on a test apparatus known as the Chase machine.
The coefficient of friction measured by the Chase test describes the relationship between the two forces acting on the friction material. A clamping force is exerted on the friction material, resulting in a frictional or resistance force. A low coefficient of friction means that very little of the clamping force is transferred into resistance force. On the other hand, a high coefficient of friction means that given the same level of clamping force, a higher resistance force is generated by the brake pad.
For example, a pad that carries an HH code has a normal coefficient of friction of 0.55 or higher, and a hot coefficient of friction of 0.55 or higher.
The first letter of the code represents the normal friction coefficient. This is defined as the average of four test data points measured at 200, 250, 300 and 400 degrees Farenheit.
The second letter of the code represents the hot friction coefficient based on a fade and recovery test. We all should know what brake fade is. If you've ever had to use the front brake extensively and found that its effectiveness quickly diminished, that's fade. Recovery is basically the period where the brakes are gradually cooling off.
The hot friction coefficient is defined as the average of 10 data points located at 400 and 300F. On the first recovery cycle of the pad; 450, 500, 550, 600 and 650F. On the second fade cycle; and 500, 400, and 300F on the second recovery cycle.
The range of friction coefficients assigned to each code letter are as follows: C = less than 0.15. D= 0.15 to 0.25. E= 0.25 to 0.35. F= 0.35 to 0.45. G= 0.45 to 0.55, and H= over 0.55.
6. What types of brake fluids are available for my vehicle?
There are three main components or considerations that must be addressed when selecting the proper brake fluid for your braking system. The first is the DOT-specified compliance of your brake system: DOT 3, DOT 4, DOT 5, or DOT 5.1. You can find this information in your owner's manual. In general, DOT 3 and DOT 4 fluids and systems are compatible with each other, and are differentiated by their dry and wet boiling points (more on this later). Some synthetic DOT 5.1 fluids are also compatible with DOT 3 and DOT 4 fluids/systems. DOT 5 fluids are silicone based, and must NEVER be mixed with a DOT 3 or DOT 4 fluid/system, and vice-versa.
The second consideration is the boiling point of the brake fluid. For brake fluids, there are two key temperature points that you should be aware of: the dry boiling point and the wet boiling point. The dry boiling point is the temperature at which the brake fluid will boil when freshly installed. The wet boiling point is the temperature at which the brake fluid will boil after it has absorbed moisture from the environment; i.e. after being used in the brake system for a while. The most important of the two is arguably the wet boiling point, especially for those who do not change their brake fluid often.
The third point to consider is the hydroscopic nature of the fluid, often termed "hydroscopicity". Quite simply, a brake fluid's hydroscopicity is its propensity to absorb moisture: a brake fluid that is very hydroscopic will absorb moisture at a faster rate than a brake fluid with a low(er) hydroscopicity. In general, high-performance brake fluids which are designed for use on the street (where the vehicle owner is assumed to change the brake fluid on an annual basis, on average) have a low hydroscopicity (along with lower dry and wet boiling points), while brake fluids designed for use In a performance environment will have a higher hydroscopicity (along with a higher dry and wet boiling points). There are exceptions to this general rule-of-thumb, of course, but "in general" these statements are correct.
7. What is the proper method for bleeding brakes?
When bleeding brakes it is best to manually bleed them as pressure bleeders can cause cavitation and bubbles inside the system. Empty the brake reservoir with a turkey baster then fill the reservoir with a high quality brake fluid. Start bleeding at the furthest wheel away from the Master Cylinder and progress to the closest. So that would go right-rear, left-rear, right-front and left-front. Attach a length of clear Tigon tubing (available form any auto parts store) to the bleeder nipple, put the other end of the line into some sort of container so the other end will be submerged in brake fluid and open the nipple. Have someone in the car to pump the brakes. Slowly pump all of the old fluid out of the line until new clear fluid comes out and then have the person in the car hold the pedal down while you close the bleeder. Have the person lift the pedal up slowly and then push down slowly while you open the nipple. You have to communicate with the pumper because the bleeder should only be open on the down stroke of the brake pedal. It is important to pump slowly to avoid bubble-forming cavitation. Continue to pump until you cannot observe any bubbles in the clear Tigon tube.
Get a rubber mallet and tap the caliper to dislodge any bubbles that may be stuck inside the caliper and bleed some more until no more bubbles come out. Do this at all the wheels and you are done. Be careful not to let the reservoir run dry or you will have to start all over. On ABS equipped cars you want to be extra careful about this because it takes forever and a lot of fluid to bleed a completely dry ABS system. Some ABS cars require bleeding from nipples on the ABS modulator so check your manual.
NEW PADS INSTALLED
Once installation has been completed, a test drive should be done to ensure proper brake system operation and to
“break in” or “burnish” the pads to the rotors.
The “break-in” is a required process, which must not be overlooked, in order to achieve optimum performance of
your new GranSport pads. To perform the “break-in”, follow the steps listed below:
Step 1: Make 10 stops from 30 mph (50 kph) down to about 10 mph (15 kph) using moderate braking pressure and
allowing approximately 30 seconds between stops for cooling. Do not drag your pads during these stops. After the 10th
stop, allow 15 minutes for your braking system to cool down.
Step 2: Make 5 consecutive stops from 50 mph (80 kph) down to 10 mph (15 kph). After the 5th stop, allow your
braking system to cool for approximately 30 minutes. This completes the “break-in” of your pads to the rotor surface.
During Steps 1 & 2, a de-gassing process occurs which may produce an odor coming from your pads as they complete
the “break-in” cycle. This odor is normal and is part of the process your pads must go through to achieve their ultimate
level of performance. The odor will go away after allowing your braking system to cool for approximately 30 minutes.
As with any new set of pads, do not tow a trailer or do any hauling during the “break-in” period.
Full seating of your new brake pads normally occurs within 1000 miles.
Big Brakes look impressive - but are they a good idea?
The "Big Brake Mistake"
Words and pictures: Rob Bell
If you read performance car magazines - particularly those that deal with performance modifications to normal road cars, one of the first areas that authors emphasise is upgrading of brakes as one of the first steps you should take. After all, this seems to make perfect sense; if you are looking at big performance gains surely you need bigger brakes to match that performance? Yes it does - but only if the brake upgrades are performed and engineered properly. Why might larger brakes be beneficial?
1. If you are using all that extra performance, you may discover that you are using the brakes far more frequently - and if on track, you will be attempting to slow the car down from higher speeds that were achievable before the modifications had been performed. This means more heat. Larger rotors and pads have much better heat dissipation properties. Result: less brake fade and less disc and pad wear.
2. Larger rotors mean that the calipers biting on the rotors have more leverage. The upshot of this is that maximum retardation can be more rapidly applied, and requires less pedal effort. This is most noticeable from very high speeds where more force may be required to slow the rotational velocity of the road wheels. This can result in shorter stopping distances - but largely this is dependent upon how effective your old standard brakes were!
3. Uprated calipers using multi-pot designs (such as AP racing/ HiSpec/ Mike Satur/ Wilwood/ Brembo etc that all have 4 or more pots per caliper) offer improved pad stability. The benefit of this is that the pad is less likely to rotate in the caliper resulting in 'taper-wear' where the leading edge of the pad wears faster than the trailing edge. High-end calipers, such as those sold by Brembo [read more here], actually use larger pistons at the trailing edge of the pad, and smaller pistons at the leading edge in such a way that is specifically designed to over come this phenomenon of taper-wear [Taper wear references: RPMnet, StopTech].
All this sounds great - we should all rush out and buy bigger brakes for our car immediately! HOWEVER, there are plenty of opportunities to get things very wrong and actually make the brake performance rather worse than the apparently puny brakes fitted to your car as standard. There's a lot more to brakes than might immediately catch the eye - and this is the purpose of this page to explore some of these intricacies in more detail and in particular reference to the MGF/TF. Plus we shall explode the biggest brake myth of all: that bigger brakes automatically mean more stopping power!
Background part one: weight transfer
Background part two: the Traction Circle
The #1 urban myth regarding brakes: "Big Brakes mean I can stop more quickly"