How To Make Custom Brake Caliper Brackets? Trust The Answer

If you’re a drift enthusiast and you’re still using the stock E-Brake setup with the single caliper on your car, you’re surely missing out on something truly amazing. Upgrading to dual brake calipers can greatly improve your drifting experience. Dual brake calipers give you more stopping power and also allow you to use hydraulic e-brake for drifting. When you pull the hydro-e brake, it locks the rear tires, giving you more control over your car when drifting. The stock e-brake on the car is generally cable operated and you have to pull it really hard and multiple times for it to do anything. And even then, it’s not a reliable way to get the rear brakes to lock up. The use of two calipers and a hydraulic e-brake will help you drift. With the right tools, you can easily install a dual caliper on your car that you use for drifting. You can also get a dual rear caliper kit for the necessary tools required for installation.

Dual caliper mounts

Dual caliper brackets are of great importance when mounting two brake calipers. In fact, they are the components that allow the installation. The stock caliper bracket on a regular e-brake has one spot for mounting the caliper and the rest of the bracket is for mounting the dust cover. Two caliper mounts remove the dust cover and allow two calipers to be mounted on one hub. Since dual saddle mounts are different for different makes and models, just do a quick online search to find the right adapter mounts for your car model. However, it is not necessarily true that one mount will not work with another model. Before purchasing a double saddle bracket, check the details and technical specifications to ensure that the brand is suitable for your car model.

A few tips for installing dual calipers

1. When installing the caliper, make sure the bleed valve is on the top of the caliper, not the bottom. In order to bleed the air from the caliper, the air bubbles must float upwards.

2. If you don’t want to use Hydro-E-Brake and want both calipers to be connected to the stock brake system, you can get a “T-Adaptor”. This allows you to connect the calipers to the standard brake.

350Z rear dual caliper kit for Nissan 350Z

Do you want to install dual brake calipers on your Nissan 350Z? The Nissan 350Z Dual Rear Brake Caliper Kit comes with all the essential tools you need for a quick and easy installation, including brackets, rotors, brake pads and brake line. Get the kit today!

Dual Pivot Brake Service

This article will cover dual pivot caliper arm adjustment from brake mount to frame, pad adjustment to rim, pad spacing and pad centering.

2 Mounting the brake caliper The brake calipers are attached to the frame or the fork with a threaded bolt and a nut. Hold the brake centered on the rim and tighten the nut to the manufacturer’s specifications, typically 6-7Nm. Keep the calipers close to the center of the rim as this will make later pad adjustment easier. Brake mounting nut installed in fork

3 Mount the cable It makes sense to use the brake cable to keep the pads close to the rim. This makes adjustment easier. Route the cable through the barrel adjuster and through the clamp mechanism. Back off the barrel adjuster two or three turns to allow for later adjustments. Make sure the quick release is in the closed position. Press the pads onto the rim and tighten the clamp bolt according to the manufacturer’s instructions, typically to 5Nm. Secure the cable in the clamp mechanism

4 Match Pads to Rim With dual pivot brakes, each pivot position of the arm is different and the pads move in different arcs as they approach the rim. The left side arm (seen in front of the brake) acts as a side pull. This pad swings down as it moves to the edge. As this pad gets thinner, it moves down even further. The right side acts as a center train. The right pad moves up as it approaches the rim. Because of these different pad arcs, set the right pad lower on the rim’s braking surface and the left pad higher on the braking surface. Set the left pad to the top edge of the braking surface and the right pad to the bottom edge of the braking surface. Most dual pivot brakes use a pad system with convex and concave surfaces. This system allows adjustment of how the brake pad face meets the rim. Adjust the pads so that the flat side of the pad meets the flat side of the rim surface. Adjust the leading and trailing edges of the pad so that it is level and the pad is not tilted. The brake may need to be adjusted to “toe-in”. Toe is an adjustment that can reduce brake squeal. The simplest test is first to see if the brake squeaks when applied. If there is no squeak, toe is not required. Squeak is a movement of the caliper back and forth on the rim surface, creating a resonance. This effect can be reduced if the leading edge of the pad is angled to touch first, leaving a small gap at the trailing edge. Hold the pad with the trailing edge facing out and tighten the brake bolt/nut. Another method is to use a rubber band to attach a washer to the trailing edge of the pad. This technique only works if the pads use the convex-concave spacer system. Squeeze the lever slightly and loosen the pad bolt. The coating aligns itself on the rim by the pressure. Attach the pad, remove the elastic and check the toes. Using a shim on the trailing edge to create toe-in. NOTE: It is generally not recommended to bend the double pivot brake arms for “toe-in”. Install the convex-concave pads that allow for toe adjustment. Otherwise, file the block down to leave a slight gap on the back.

5 Adjust Pad Clearance Forcefully squeeze the lever to seat the cable and housing to test the security of the cable pinch bolt. Use the cylinder adjuster to adjust the pad clearance by feel on the lever. A brake that is set too tight makes it difficult to center the pads and is likely to rub against the rim while riding. If this occurs, bring the barrel adjuster down into the brake, which creates more cable slack to move the pads away from the rim. A brake that is too loose almost touches the handlebars, resulting in poor braking performance. Turn the barrel adjuster counter-clockwise, tightening slack and bringing the pads closer to the rim. Usually, front and rear brakes are set to feel the same. Adjust the brake play according to the feel of the lever

6 Centering Show centering of the pad to the rim. Dual pivot brakes typically have a center screw on one arm. Turning the screw clockwise pulls both pads to the side of the brake with the screw. When loosening the screw, both brakes move to the opposite side of the screw. Use the centering screw to center the brake pads on the rim. In these cases, move both the brake mounting nut and the brake body together. Use a brake centering wrench if there is a centering surface on the brake. Use brake centering surfaces and brake wrenches when moving the brake without centering screws

7 Cut cable and cap Finish the cable by cutting it and attaching an end cap. Cut off excess cable length and attach end cap

8 Caliper Pivot Joint Adjustment If there is excessive play in the caliper arms, adjust the brake pivot. Because each arm has a separate pivot point, each arm pivot point is adjusted separately. Neither arm should have play or throb. Also, none of the arms should pinch when moving. The caliper bridge behind each arm is threaded for each arm pivot bolt. A lock nut is located behind each pivot bolt. Dual Pivot uses a spring to open the side pull arm. A set screw in the side pull arm presses on the center pull arm to open it. To adjust the center pivot point of the right arm, first remove the brake from the bike. Loosen the set screw under the bridge. Not all makes and models use a set screw on this bridge. Campagnolo® uses a set screw in the lock nut behind the strut. Release spring tension by loosening the spring from the right caliper arm (centre-pull arm). Be careful not to damage the plastic spring guide. Loosen the lock nut at the base of the mounting bolt. It is not necessary to remove the lock nut. Shimano® typically uses a 12-point 13mm nut. Other brands vary. Mount an L-shaped allen wrench vertically in a vise. This is to hold the pintle and free your hands. Pivot the center pull side inward to expose the center screw. Put the brake on the hex key. The center bridge is threaded and can also act as its own lever. Rotate the strut clockwise slightly (10-15 degrees) to tighten it. Hold the strut and fully tighten the locknut (approximately 70 inch-lbs of torque). Test the center pivot arm for knock and play. Test the arm for sufficient freedom of movement. If the arm is binding, loosen the lock nut and slightly loosen the bridge. Secure the lock nut again and test again. Repeat as needed. Move the caliper arm to the fully open position and reinstall the return spring. Be careful not to damage the plastic spring guide. Mount the brake to the frame or use soft jaws in a vise to hold the mounting bolt. Use a hex wrench to hold the right arm adjustment screw and loosen the lock nut on the back of the arm. Tighten the adjusting screw slightly. Hold the screw and fully secure the locknut. Test the arm for play and pinch the arm against the rim and test for adequate range of motion. Mount the brake caliper on the bike and adjust the pads as described above.

Most calipers do not need to be rebuilt or replaced when the brakes are first re-padded. But after 75,000 miles, or seven to 10 years of service, the calipers may reach the end of the road. As the rubber seals age and harden, the risk of sticking and leakage increases.

Few workshops nowadays rebuild their own calipers because it takes too long and increases the risk of a comeback if the caliper sticks or leaks. It’s easier, faster and safer to simply replace the old calipers with new or remanufactured calipers. Loaded calipers are even better because they give you everything you need in one box and there is much less chance of mismatched parts.

A caliper replacement is required when a caliper is leaking fluid, has a stuck piston, or the caliper is worn or damaged. Leaks are very dangerous and should never be ignored as loss of fluid can cause brake failure.

Leaks eventually occur as the caliper ages and the piston seals harden and lose their elasticity. Corrosion in the piston bores or on the pistons themselves can also accelerate seal wear. Forcing the pistons back into the caliper to install new pads forces the piston seal to scrape over areas of the bore that may have been corroded. If the brake caliper wasn’t leaking before, you can get started soon.

The condition of the caliper guides, pins and bushings on floating calipers should also be carefully inspected for wear, rust, cracks or other damage. When replacing a caliper, use new sliders, bushings, and mounting hardware, and be sure to lubricate these parts with a high-temperature, moisture-resistant brake lubricant.

If the sliders or bushings of a floating caliper are rusted, worn, or damaged, the caliper may not move freely, resulting in uneven pad wear. A “sticky” or “frozen” caliper can also cause the brakes to drag if the caliper doesn’t slide, allowing the outer pad to kick off the rotor. This can lead to increased wear on the outer pad and to a one-sided steering angle due to the constant resistance. Fixed calipers do not suffer from this type of problem because the position of the caliper is fixed and the caliper does not move. But both fixed and floating calipers can sometimes “freeze” or bind when a piston binds or sticks in its bore due to corrosion or swelling.

When a piston is sticking, one of two things can happen: the brake may not engage or it may not release. The resulting uneven braking can create a strong pull to the “good” side when applying the brakes and/or a steering pull to the “bad” side when releasing the brakes.

If you notice uneven pad wear between the inner and outer disc brake pads, this is a sure sign that the caliper (or caliper piston) is sticking.

Calipers should normally be replaced in pairs, especially on high mileage vehicles. But if only one caliper needs to be replaced because of a leak or problem, the replacement caliper should have the same type of piston (steel or phenolic) as that on the opposite side, and the same friction material (non-asbestos, organic or semi-metallic). Side-to-side deviations can cause uneven braking. Other items that may be needed when replacing calipers are new brake hoses (replace if leaking, cracked, brittle or worn) and certainly brake fluid. Always flush the brakes to remove old fluid and bleed all lines to remove trapped air that could be causing soft pedaling.

A major cause of brake system failure is failure of the brake caliper bolts. The problem is – in most cases it is due to human error. While replacing brake pads is a fairly simple task, the problem arises when mechanics don’t take the time to properly tighten the caliper bolts. To help you avoid potentially catastrophic damage to your vehicle or an accident that causes you or others harm, here is a simple 5-step guide to tightening a caliper bolt.

Step 1: Remove the caliper bolts correctly

Like any other fastener, caliper bolts work best when properly removed and installed. Due to their location and tendency to be corroded by dirt, caliper bolts can rust and be quite difficult to remove. To reduce the potential for damage, removing the screws correctly is an important first step. Here are 3 basic tips but always refer to your service manual for manufacturer recommended steps as not all calipers are made from the same materials.

Use a good quality penetrating liquid to absorb rust on the screw. Allow the stud to soak for at least five minutes before attempting to remove it. Be sure to remove it in the right direction. Note: Although we’ve all been taught that left loose – right tight is the preferred method, some caliper bolts are reverse-threaded. This is where it is important to refer to your vehicle’s service manual.

Step 2: Check the screw and the screw holes on the spindle

After your caliper bolts have been removed and you have removed any brake parts that require replacement, the next step before installing any new components is to inspect the condition of the caliper bolt and bolt holes on the spindle. There is a very simple way to test the condition of each one. If you remove the screw and it is rusty – throw it away and replace with a new one. However, if you can clean the bolt with a mild steel brush or sandpaper, it can be reused. The key is seeing how well it fits into the bolt hole on the spindle.

The bolt should spin easily into the spindle and have no play when you insert it into the bolt hole. If you find play, the screw needs to be replaced – but you also need to move on to the next important step.

Step 3: Use a thread cleaner or “thread selector” to rethread the bolt hole

If your screw and screw hole did not pass the “backlash” test above, you will need to rethread or clean the internal threads of the screw holes prior to installation. To achieve this, you need a thread cleaner – commonly referred to as a thread finder – that precisely matches the threads on your spindle. A helpful tip is to take a brand new caliper bolt for your vehicle and cut three small sections vertically on the bolt and slowly finger tighten as it is inserted into the bolt hole. Slowly remove this thread finder and test the newly cleaned screw hole again with a new screw.

There should be no play and the screw should be easy to insert and remove before tightening. If your cleaning job is unsuccessful, stop immediately and replace the spindle.

Step 4: Install any new brake system components

After confirming that the caliper bolts and the bolt hole on the spindle are in good condition, follow your vehicle’s service manual and install all replacement parts correctly according to the exact procedure and order of installation. When it comes time to install the calipers, make sure you follow these 2 important steps:

Make sure the new threads have thread lock applied. Most replacement caliper bolts (particularly OEM components) have a thin coat of threadlocker already applied to the bolt. If not, use a liberal amount of good quality threadlocker before installation. Slowly insert the caliper bolt into the spindle. Do not use air tools for this job. This will likely cross the screw and over tighten it.

Step 5: Tighten the caliper bolts to the recommended torque

This is where most home mechanics make a crucial mistake by searching online or asking on a public forum for the correct torque pressure to tighten the caliper bolts. Because all calipers are unique to each manufacturer and often made from different materials, there is no universal caliper torque-pressure setting. Always refer to your vehicle’s service manual for the correct procedures on using a torque wrench on your calipers. If you don’t want to invest in a service manual, a call to your local dealer’s service department may help.

Every day in the United States, more than a million brake pads are replaced by qualified mechanics. They too make mistakes when it comes to installing brake caliper bolts. The points listed above will not 100% avoid potential problems, but they will significantly reduce the chance of errors. As always, make sure you are fully conversant with this job, or seek the advice or assistance of a professional mechanic.

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There are some car problems that you just shouldn’t ignore. Brake problems are perhaps the most important among them. A car that cannot stop or has trouble stopping is dangerous for the driver and all other road users. That’s why it’s important to keep all parts of your brakes in good working order.

First, let’s talk about calipers and what they do. On a disc brake equipped car, the caliper sits like a clamp over the brake rotor (the circular metal disc inside your wheel). Inside the caliper is a pad, a small block of friction material backed by a metal plate. When you step on your brake pedal, pistons in the caliper cause it to put pressure on the brake pad, which compresses the rotor, causing the car to slow or stop.

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At least that’s the idea. But if one or more parts of your calipers aren’t working properly, or if they’re not installed properly, you could have trouble stopping. If you are doing any work on your brakes, you need to make sure there are no problems with your caliper guide pins.

The caliper guide pins are two round metal pins on each caliper that the brake piston assembly sits on. They are called guide pins because they are responsible for guiding the correct angle for how the pad meets the rotor.

On the next page we examine how to tell if your caliper shaft pins are causing problems and how to fix them if they are.

How can I tell how many pistons my brake calipers have?

Our brake finder often asks: “How many pistons do the front/rear brake calipers have? Don’t worry! You probably don’t even have to take your bike off to find the answer. Modern vehicles typically have open wheel designs to make it easy to visually confirm how many pistons the calipers have.

In general, with 1 and 2 piston calipers, you can often see “arches” on the front of a caliper. By counting the arcs you can usually tell how many pistons are in the caliper. 4 and 6 piston calipers are a bit trickier, but you can usually still see the outlines of the 2 or 3 outer pistons.

Below we discuss what caliper pistons are and explain the differences between different types.

Starting with the basics, what is a caliper piston?

Calipers are essential components of an overall braking system and the pistons are the key components of calipers. Pistons are responsible for the brake pads coming into contact with the brake disc and bringing a vehicle to a standstill.

When the brake pedal is depressed, brake fluid is directed from the master cylinder into the caliper and the pistons are pushed out from behind the brake pads. This forces the pads to make contact with the rotors. When the brake pedal is released by taking your foot off the pedal, the drop in brake fluid pressure causes the pistons – and therefore the brake pads – to retract.

How many pistons are in a caliper?

Calipers are very different. Below we examine different types of calipers based on the number of pistons used.

Single-piston calipers

Single-piston brake calipers (1) are always sliding calipers that move slightly when the brake pads wear. Most have a mount. However, in some applications the bracket is built into the steering knuckle of the vehicle. Also, some rear single-piston calipers have a parking brake mechanism on the back.

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Dual-piston calipers

Dual piston calipers (2) are usually sliding calipers with brackets, but some 2-piston calipers have a fixed position with opposed pistons – one on the inside and one on the outside.

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4 piston calipers

4-piston calipers almost always have 2 inner and 2 outer opposing pistons. 4-piston calipers are usually a fixed position design. This means you don’t see the bracket surrounding the caliper, like in the 2-piston caliper above. Instead of seeing 2 “arcs” you see 2 general outlines of the 2 outboard pistons

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6 piston calipers

6-piston calipers usually have 3 inner and 3 outer opposing pistons. They are almost always fixed calipers without holders, similar to the 4-piston design. With 6 piston calipers you can usually see the outline of the 3 pistons on the outside of the caliper

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What are signs of a bad brake caliper?

When calipers fail, it’s important to address the problem immediately. If brake problems are allowed to persist for too long, not only is safety compromised, but small, relatively inexpensive repairs can become large problems that are more costly to fix.

If you notice any of the following warning signs of a bad caliper, have your braking system checked as soon as possible.

Leaking brake fluid

Hydraulic pressure is an essential part of how calipers work, so weak points in the system can allow brake fluid to leak. If you notice a wet, oily patch on the ground near a tire, it could be an indication of a leaking caliper.

Uneven wear of the brake pads

Brake pads often wear out unevenly when calipers fail. If your vehicle’s brake pads are worn thinner on one side than the other, this could very likely be due to a faulty caliper.

Squeaking or metallic grinding noises

When calipers stick or freeze, you may hear noises coming from the area of ​​the damaged part. Although there is a squeaking noise when the brake pedal is depressed due to worn brake pads, the caliper squeak is most noticeable when you are not depressing the brakes. If this problem is ignored for too long, the brakes can lock up completely, preventing the wheel from turning.

Vehicle pulls to one side

Within a caliper, one or more pistons move in and out in response to hydraulic pressure from the master cylinder when the brake pedal is depressed. If the piston(s) in one of the front brake calipers freezes due to corrosion, deposits or dirt, the brake pads will either not be able to make contact with the brake disc or will not release the brake disc when the brakes are released. If the brake pads are not touching the rotor, the vehicle will pull away from the damaged side when you press the brake pedal. If the brake pads don’t dislodge the rotor, the vehicle will pull toward the damaged side when the brake pedal is depressed (and sometimes when it isn’t).

knocking sound

In some cases, a caliper bracket holding the caliper in place can break and make a loud rattling noise. In this case, the vehicle must not be driven.

Have a question? PowerStop can help!

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Double air brake

Most heavy duty vehicles use dual air brake systems for safety. A dual air brake system has two separate air brake systems that use a single set of brake controls. Each system has its own air tanks, hoses, lines, etc. A system typically applies the regular brakes on the rear axle or axles. The other system applies the regular brakes on the front axle (and possibly a rear axle). Both systems supply air to the trailer (if present). The first system is referred to as the “primary” system. The other is called the “secondary” system. See Figure 5.4.

Before operating a vehicle with a dual air system, allow the air compressor to pressurize at least 100 psi in both the primary and secondary systems. Watch the primary and secondary barometric pressure gauges (or needles if the system has two needles in one gauge). Pay attention to the low air pressure warning light and buzzer. The warning light and buzzer should turn off when the air pressure in both systems rises to a manufacturer specified level. This value must be greater than 60 psi.

The warning light and buzzer should illuminate before the air pressure in either system drops below 60psi. If this happens while driving, you should stop immediately and park the vehicle safely. If an air system is very low in pressure, either the front or rear brakes will not function fully. That means it takes you longer to quit. Stop the vehicle safely and have the air brake system repaired.

5.3 – Inspection of air brake systems

You should use the basic seven-step inspection procedure outlined in Section 2 to inspect your vehicle. There are more things to check on a vehicle with air brakes than on one without. These things are discussed below in the order that they fit into the seven-step method.

5.3.1 – During step 2 engine compartment checks

Check the air compressor drive belt (if the compressor is belt driven). If the air compressor is belt driven, check the condition and tightness of the belt. It should be in good condition.

5.3.2 – During step 5 walkaround inspection

Check slack adjusters on S cam brakes. Park on level ground and block the wheels to prevent the vehicle from moving. Release the parking brakes so you can move the slack adjusters. Wear gloves and pull hard on any slack adjuster you can reach. If a slack adjuster moves more than approximately 1 inch at the point where the push rod attaches to it, it likely needs adjustment. Adjust or have adjusted. Vehicles with too much brake play can be very difficult to stop. Adjusted brakes are the most common problem found at roadside inspections. Be sure. Check the slack adjusters.

All vehicles built after 1994 have automatic slack adjusters. Even if automatic slack adjusters adjust themselves in the event of emergency braking, they must be checked.

Automatic adjusters should not require manual adjustment except during brake maintenance and slack adjuster installation. On a vehicle equipped with automatic adjusters, if the pushrod travel exceeds the legal brake adjustment limit, this is an indication that there is a mechanical problem in the adjuster itself, there is a problem with the associated basic brake components, or that the adjuster was improperly installed.

Manually adjusting an automatic adjuster to bring the brake linkage travel within legal limits generally masks a mechanical problem and does not fix it. Also, routine adjustment of most automatic adjusters will likely result in premature wear of the adjuster itself. It is recommended that the driver take the vehicle to a repair facility as soon as possible if self-adjusting brakes are misaligned to have the problem corrected. Manual adjustment of automatic slack adjusters is dangerous as it can give the driver a false sense of security as to the effectiveness of the braking system.

Manual adjustment of an automatic adjuster should only be used as a temporary measure to correct the adjustment in an emergency situation as it is likely that the brake will soon be out of adjustment again as this procedure does not usually correct the underlying adjustment problem.

(Note: Automatic slack adjusters are made by different manufacturers and do not all work the same. Therefore, before troubleshooting a brake adjustment problem, consult the manufacturer’s service manual.)

Check brake drums (or discs), pads and hoses. Brake drums (or discs) must not have cracks longer than half the width of the friction surface. Linings (friction material) must not be loose or soaked with oil or grease. They must not be dangerously thin. Mechanical parts must be present, not broken or missing. Check the air hoses connected to the brake cylinders to ensure they are not cut or worn from friction.

5.3.3 – Step 7 Final check of the air brake

Perform the following checks in place of the hydraulic brake check described in Section 2, Step 7, Check Brake System.

Test the low pressure warning signal. Shut off the engine when you have enough air pressure so that the low pressure warning light is not on. Turn on the power and step on the brake pedal to release the air tank pressure. The low air pressure warning light must illuminate before the pressure in the air tank (or the lowest air pressure tank in dual air systems) drops below 60 psi. See Figure 5.5.

If the warning signal does not work, you could lose air pressure without realizing it. This could result in sudden emergency braking in a single circuit air system. With dual systems, the braking distance is longer. Braking is only possible to a limited extent before the spring-loaded brakes apply.

Check that the spring brakes activate automatically. Continue deflating by pressing and releasing the brake pedal to relieve tank pressure. The tractor guard valve and parking brake valve should close (pop out) on a tractor-trailer combination and the parking brake valve should close (pop out) on other combination and individual vehicle types when the air pressure meets the manufacturer’s specification (20 – 45 psi). This activates the spring brakes.

Check the rate of air pressure build-up. With the engine running at operating speed, pressure in dual-air systems should build from 85 to 100 psi within 45 seconds. (If the vehicle has air tanks larger than the minimum, the build time may be longer and still be safe. Check the manufacturer’s specifications.) In single air systems (pre 1975) typical requirements are a 50 to 90 psi build pressure within 3 minutes with the engine at an idle speed of 600-900 rpm.

If the air pressure does not build up quickly enough, your pressure may drop too low while driving, necessitating emergency braking. Don’t drive until you fix the problem.

Test the air leakage rate. With the air system fully charged (typically 125psi), shut off the engine, release the parking brake and measure the air pressure drop. The loss rate should be less than 2 psi in a minute for single vehicles and less than 3 psi in a minute for combination vehicles. When air pressure builds up to the point where the regulator shuts off (120-140 psi), shut off the engine, lock your wheels (if necessary), release the parking brake (all vehicles) and tractor protection valve (estate vehicles); and fully depress the foot brake. Hold the foot brake for one minute. After the initial drop in pressure, if the air pressure drops more than 3 psi (more than 4 psi for station wagons) in one minute for single vehicles, the air loss rate is too high. Check for air leaks and fix before driving the vehicle. Otherwise you could lose your brakes while driving.

Check the air compressor regulator cut-in and cut-out pressures. The air compressor should start pumping at about 100 psi and stop at about 125 psi. (Check manufacturer’s specifications.) Run engine at fast idle. The air regulator should shut off the air compressor at approximately the pressure specified by the manufacturer. The air pressure displayed by your gauge(s) no longer increases. With the engine idling, apply and release the brake to relieve the air tank pressure. The compressor should turn on at about the cut-in pressure specified by the manufacturer. The pressure should start to rise.

If the air regulator does not function as described above, it may need repairing. A regulator that is not working properly may not be holding enough air pressure for safe driving.

Test parking brake. Stop the vehicle, apply the parking brake and gently pull against it in a low gear to test if the parking brake is holding.

Test the service brakes. Wait for normal air pressure, release the parking brake, move the vehicle slowly forward (approx. 8 km/h) and apply the brakes firmly with the brake pedal. Check for vehicle “pulling” to one side, unusual feeling, or delayed braking.

This test can show you problems you wouldn’t otherwise know about until you needed the brakes on the road.