Today we are going to talk about how to fix a leaking brake line fitting. If you are having any problems with your brake line, please do not hesitate to call us. In this amortips.com post, We would be happy to help you out.
Brake lines can leak when there is a poor connection between the seat of the fitting and the brake line. This type of leak is commonly known as weep.
Despite using various flare tools, I was never able to achieve a clean, concentric finish on my flares that would allow the flare to seat properly with the fitting. Furthermore, regardless of which type of lines I used, the finished product always looked inconsistent and lacked precision. On the left you can see tiny imperfections on the flare. The flare on the right has a “lapped” finish.
A leaking flare connection can be caused by a number of things, but often the problem is with the flare itself. If the fitting is damaged in some way, it can become very difficult to fix.
Lapping is a common practice that has been used for 100 years. Even with the best equipment, mechanics always lapped engine valves to ensure they wouldn’t leak. Recently, I thought of applying this practice to flared tubing and it fixed my leak.
1. Unscrew the brake line from the fitting.
2. Clamp the line with the appropriate-sized collet.
3. Attach it to the Surseat lap tool.
4. Before using the lapping head, spray it with lubrication.
5. 6-10 times, rotate the lapping head back and forth.
6. Inspect and clean the flare. The finish should be smooth and concentric. If not, go back to step 5.
7. Remove the Surseat’s brake line and reattach it to the fitting.
8. Check the seal and bleed the brakes.
1. Insert the fitting via the Fitting Fixer guide.
2. Connect the lapping head to the handle of a drill or tap.
3. Spray some lubrication into the lapping head cavity.
4. Place the lapping head over the fitting and into the guide.
5. Spin the lapping head on the fitting, releasing every 2-3 seconds to avoid clogs.
6. Remove the fitting and check the surface after 5-6 passes. Repeat step # 5 if required.
If your brake or fuel line is out of your vehicle, there is an easy way to determine if there’s a leak at the fitting.
To check the pressure in a tube, you can either screw in a cap flared tube nut or purchase an Earl’s Performance Pressure Test Kit.
If air bubbles appear at the fitting when you lap it, the seal is no good. You’ll need to replace it.
The first step in repairing a brake fluid leak is to diagnose its location and severity. Once you have determined the location and severity of the leak, you will need to make the repair.
If you notice fluid leaking from your brake system, it is important to check the reservoir on the driver’s side near the rear of the engine compartment. If there is a low fluid level, then you may have a leak.
To verify a leak, check beneath the car for the presence of brake fluid. If the brake fluid is located near or at the wheel, it is likely that the leak is near or at that location.
Additionally, if there are any wet spots on nearby surfaces (such as grass), it’s possible that a leak has occurred and can be detected this way.
Place newspapers on the ground beneath the general location of the leak. Pump the brake pedal to force fluid out through the leak. Make sure that your car is not turned on for this process. Turning on the car would cause brake fluid to squirt out very quickly and make controlling a more difficult, if not impossible, task.
If you notice fluid dripping from your car’s brakes, it may be necessary to check the brake lines and calipers for leaks.
Inspect the master cylinder for leaks. Depending on the model of car, it may be located in a different spot. You can find your car’s owner’s manual to locate the master cylinder’s location. If you no longer have a copy, then check online to find an original manual.
To ensure that no fluid escapes from the master cylinder lid, make sure it is securely closed.
Remove the old caliper.
Replace the piston.
Replace the caliper.
Bleed all air from the brake system.
If your wheel cylinders are weeping brake fluid, it’s probably time to replace them. Replacing the wheel cylinder with an entirely new unit is much easier and only slightly more expensive than rebuilding the part.
Remove the wheel.
Remove the brake drum.
Loosen the steel brake line.
Replace the wheel cylinder.
To bleed the air out of your brake system, follow method six.
If brake hoses are showing signs of wear and tear, such as cracking or becoming spongy or sticky, then they should be replaced. Brake lines that have patches of rust on them may also be in need of replacement due to the metal weakening from corrosion. If there are thin spots in the steel walls of the brake line, it may be time to replace them.
Remove the brake line from the fitting closest to the master cylinder. Use a flare nut wrench to unscrew it.
Remove the mounting bracket clips that hold the brake line in place. Then disconnect the brake line from the brake caliper using a line wrench.
Attach the new brake line to the caliper using bracket clips. Make sure the line is of equal length to the old one.
Attach the brake line to the fitting closest to the master cylinder using a line wrench. Tighten all connections.
Brake system bleeding is a procedure used to clear air from the brake system. It is described in method six of the car’s owner’s manual.
Most modern brake systems have two circuits, with two wheels on each system. If one circuit fails, the brakes on the other system will still work. The master cylinder supplies pressure to both circuits. Replacing the master cylinder is usually cheaper than having an in-shop rebuild.
Locate the master cylinder and remove the cap to access the brake fluid.
Remove brake fluid from the master cylinder using a turkey baster. Pour discarded brake fluid into a plastic container.
Remove the brake lines by turning a wrench in a counterclockwise direction.
a socket wrench can be used to remove the mounting bolts.
To install the new master cylinder, secure mounting bolts and connect brake lines.
Connect the new master cylinder to the electrical connectors. Bleed all air from the brake system.
Bleed all air and brake fluid from your system and replace it with new brake fluid. Brake pads will need to be replaced along with the new brake fluid.
Remove the cap on top of the master cylinder to release brake fluid.
To empty the master cylinder, use a turkey baster to draw all of the fluid from it. Pour any used fluid into plastic bottles and clean out any sediment with a lint-free rag.
Refilling the brake fluid reservoir with new fluid is a regular maintenance task you should complete. To find out which brake fluid is appropriate for your car, consult your owner’s manual or the underside of the reservoir cap.
To bleed the brakes on your car, loosen the bleeder screw located on the caliper or wheel cylinder at the right rear of your vehicle. Bleed each brake one at a time to avoid drawing air into the system.
Attach a vinyl hose to the bleeder screw. Place the opposite end of the vinyl hose into a clear plastic bottle.
Please instruct your assistant to press the brake pedal as far down as it will go.
After all of the air bubbles are released, tighten the front right brake fluid bleeder screw.
Please have the assistant pump the brake pedal until it becomes hard and builds up pressure. This will draw fluid into the master cylinder. The fluid should squirt into the bottle each time he/she pumps the brakes. Do this until new, fresh brake fluid starts coming out.
Please have your assistant press the brake pedal again to tighten the brake fluid bleeder screw and remove the hose.
Top off the master cylinder with brake fluid.
In order to test the brakes, it is necessary to top off the master cylinder with brake fluid.
Brake lines can leak when there is a poor connection between the seat of the fitting and the brake line. This type of leak is known as a weep, and it is the result of a tiny imperfection in the flare that occurs while flaring the tube.
To prevent a leak at the joint between the flare and cone, loosen and tighten the flare nut several times to the torque specifications.
Brakes need to operate under high pressure and cannot rely on anything to stop a leak. Teflon tape can damage the system if it is used on the brake lines.
If the leak is on a branch leading to a brake line, you can use crimping tools to create a seal. This will stop the fluid from leaking and give you full pressure in your other lines.
If you’re using your brake system correctly and don’t need any lubricants or sealers, you can avoid contaminating the system with oil or other fluids by using clean brake fluid.
Using a regular rubber line with a brake system is not recommended due to the high pressure exerted on the line by the brakes. Additionally, brake fluid can damage rubber hoses over time.
To tighten a nut, start by tightening it finger-tight and gradually increase the pressure until you feel it draw down tight. Then tighten by 1/6 turn. Do not over-tighten.
Staying away from Teflon tape on any brake/fuel system is always a good idea, as any good pipe thread sealant (paste) with Teflon or PTFE will do the job just as well.
|Type of Leak||Repair Cost|
|Repair||Parts = $100-$200 Labor = $80-$140|
|Replace||Parts = $200-$300 Labor = $40-$80|
|Brake Line Leak|
If you’re looking to solder brakeline, you need the right flux and silver solder. Use a MAP gas torch to ensure a good connection.
Do not use sealants or lubricants on brake lines; only brake fluid should be used when assembling the brake system. If the flare/cone seal of the brake fittings does not provide a seal, then the parts must be replaced. There are no safe methods to fix these parts if they do not meet this standard.
Seal-All is a household product that can be used on metal, glass, wood and leather. It is the only product I have ever used that will withstand exposure to gasoline or brake fluid (DOT 3 and DOT 4).
If you notice any wet or dry fluid streaks on the inside of your car’s wheels, rust spots along the brake line lines, or any drips, you may have a brake line leak.
Some people believe that it is illegal to make a new section of brake line and splice it into a non-rusted section of your old brake, but this is not actually the case. You must use automotive grade SAE double/inverted flare, SAE “bubble” flare and DIN Single Mushroom flare unions and fittings in order to avoid any problems.
Do not use hydraulic fluid to apply the brakes because it will deteriorate the hose and make it gummy and collapse.
Replacing a hard brake line with a braided one will result in a softer pedal. This is due to the fact that the braided line can expand where the original steel line cannot.
A leaky pipe can be fixed with Flex Seal Tape or Liquid. You’ll be hard pressed to find a repair that can’t be fixed with a Flex Seal product.
Epoxy putty or pipe putty can be used as a temporary fix to a leaky pipe. This type of putty hardens at room temperature and seals the hole or crack.
Fourth, do not over tighten the flare fitting as this can cause leaks. Daikin offers preset torque wrenches that will allow you to properly tighten the flare fitting without over tightening them. Always use a backup wrench when tightening any flare fitting.
You should expect to pay around $150 to $200 for a steel brake line repair. The cost of just the parts is usually between $30 and $50, while the rest of the cost is typically labor involved.
Brake fluid is a liquid that transfers the pressure from your brake pedal to the brakes. Without it, your brakes would not work.
Metal brake lines burst around 15,000 psi. Brake line pressures vary depending on the type of brakes, but are typically around 900–1,000psi (69 bar) with manual brakes and 1,400-pluspsi (96 bar) with power-assisted brakes.
If you are having any problems with your brake line, please do not hesitate to call us. We would be happy to help you out. Thank you for reading.