I just replaced my brake master cylinder and the brakes still feel soft. What do I need to do after I replace the master cylinder
I just replaced my brake master cylinder and my brakes still feel soft. what do I need to do now after replacing the master cylinder. also I have a check engine light on my dash now. I took it to be read and it states brake booster leak. what could that be?
My car has 240000 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
From what you’ve described you will have to bleed your brakes. Also, I believe you may have a leak in one of the lines. You may want to use a wrench and tighten the lines a little more. If you’re unable to fix this yourself, consider YourMechanic, as one of our mobile technicians can come to your home to bleed your brakes, diagnose the Check Engine Light, and help you make the appropriate repairs to your car.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
Low Brake Fluid Could Trigger Check Engine Light | Auto Lab Libertyville IL.
The metal brake lines attached to the master cylinder can leak fluid at the threaded connections, or from the internal O-rings. When this happens, the fluid will drip down the power brake booster (the booster is what the master cylinder is bolted to).
A: Brake fluid leaks are often caused by a worn seal in the master cylinder, caliper, or wheel cylinder. If you suspect your car is leaking brake fluid, call a tow truck to take your vehicle to a service provider for a brake fluid inspection. Brake fluid leaks can lead to total brake system failure.
Another system that experiences failures that causes illuminated CEL is the brake system. Everything from low fluid levels in the lines to unevenly worn brake pads can cause this light to illuminate.
When you get this combination of warning lights and symptoms it is typically the result of a battery that has failed. If the battery voltage gets low enough then the check engine light and the brake light can come on as they can no longer function without suitable power.
If your foot slowly sinks to the floor with normal pressure on the brake pedal, the master cylinder is leaking internally. To diagnose a clutch master, clamp the rubber fluid line near the slave and press the clutch pedal. If the master cylinder is good, the pedal won`t move.
Failed Brake Booster Seal Causes Master Cylinder Leak.
When a brake leak is present, it affects the fluid pressure in your system. Since it is that pressure that actually causes your wheels to slow or stop when you activate the brake pedal inside your vehicle, your brakes will fail to engage once the fluid levels are too low.
Without question, the most common symptom of a problematic brake master cylinder is a spongey, or even sinking, brake pedal. Brake fluid will also often leak from a faulty cylinder leaving tell-tale fluid puddles underneath your car. Braking performance may also be impeded as the part starts to fail.
If you suspect your brake fluid is leaking, do not attempt to drive it. Look under your hood and check the brake fluid reservoir. An empty reservoir means that your brakes have been leaking for a while. Have your vehicle towed to your mechanic for a professional repair.
In today`s video, the brake brainiacs at Raybestos explain why you should be mindful of not overfilling your master cylinder, because it can lead problems such as: Unwanted brake drag. Brake system overheating. Premature brake pad wear.
The battery and Check Engine Lights coming on may indicate that leaking coolant may have sprayed onto other components like the alternator or possible the serpentine belt which drives the water pump, alternator and air conditioning compressor may have broken off, or may be slipping due to coolant leaking all over it.
Yes! Brake fluid is a very poor lubricator and very damaging to engine parts that require lubrication ,which most engine parts do. Rubber seals and gasket in a engine is not compatible with brake fluids either. Many types of brake fluids Dissolves in water and react like water in a engine.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
I just replaced my brake master cylinder and the brakes still feel soft. What do I need to do after I replace the master cylinder
ANSWER : From what you’ve described you will have to bleed your brakes. Also, I believe you may have a leak in one of the lines. You may want to use a wrench and tighten the lines a little more. If you’re unable to fix this yourself, consider YourMechanic, as one of our mobile technicians can come to your home to bleed your brakes, diagnose the Check Engine Light, and help you make the appropriate repairs to your car.
Soft brake pedal after replacing rear brakes and master cylinder 2003 Audi A4
ANSWER : Hello. If you have no pressure to the rear calipers at all and if the master cylinder is new then you may have forces some debris into the ABS unit when you compressed the pistons in the rear calipers. In some cases the system can be pressure bled to fix it but it may need a new ABS unit.
Low brake pedal and anti-lock brakes are not kicking in.
ANSWER : The brake pedal is working to stop the vehicle, but there may be air in the controller unit causing the ABS brakes to not function. I recommend bleeding the brake system from the farthest location from the master cylinder to the master cylinder including the ABS unit. If the brakes are still spongy after a full bleed, then the controller will need to be replaced. If you need further assistance with your brake pedal being spongy, then seek out a professional, such as one from Your Mechanic, to help you.
Changed brake master cylinder, bled 10 times, and the pedal is soft The rear brakes are not locked but close. Truck now running rough.
ANSWER : You will have to bleed the brakes from the farthest location all the way to the master cylinder. There is still air in the lines causing the issue. Check the vibrations on the vehicle to see if the engine mounts are damaged or if the brakes are not releasing causing the engine to run harder than normal to overcome the braking force. If you need further assistance with your vehicle’s brake system, then seek out a professional, such as one from Your Mechanic, to help you.
Brake pads replaced but still feel soft
ANSWER : It sounds like your 2006 Freestar does have a legitimate brake issue and the mechanics you are currently going to have not identified it. You need to have confidence that your brakes are "working as designed" and will stop your vehicle! You may want to speak with management and give them one more try at making it right. Diagnosing and repairing brakes should be a fairly easy job for a trained mechanic. Make sure that you are using top quality parts and are following correct procedures. If you do not feel comfortable going back to the same shop, have a certified mechanic, such as one from YourMechanic, come to your home or office to diagnose and repair your brake issue.
I replaced the brake light switch. Gear lever unlocked because it had locked. Now the brakes feel hard.
ANSWER : Hi, thanks for writing in. You need to check the brake switch install adjustment. You may have the switch adjusted too tight and it is holding the the brake pedal partly down. This will cause the brake master cylinder to not release the brakes when you let off the pedal. Readjust the switch away from the pedal until you feel some free play again in the pedal. This should fix the problem. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.
Replaced master cylinder and brakes still going to the floor and not working. Bed both master cylinders and each wheel.
ANSWER : Hi, thanks for writing in. At first it sounds like you may still have air in the system. The other option is that you may have a leak somewhere. Try to bleed the master cylinder and the lines again. The new master cylinder must be bench bled off of the vehicle exactly as the instructions say. The other problem could be a leak on the system. You should check for drips, puddles forming, or other signs of leaking brake fluid. Worst case scenario, the replacement master cylinder may have come to you faulty in the first place. This is rare but can happen, especially when it comes to remanufactured master cylinders. New ones typically don’t have issues. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.
I need to replace the master cylinder brake on my 1988 Grand Marquis
ANSWER : The brake master my need to be replaced but you still need to locate the leaks first if you are losing fluid. You should have every brake line checked to see what is leaking. If the lines are rusted and corroded then they all may need to be replaced. The master cylinder can then be replaced by a mechanic like one from YourMechanic. You may need to activate the anti-lock brakes with a scanner in order to bleed out the brakes correctly. Replacing the major components of the brake system take skill and expertise and should not be taken on if you are not experienced or do not have the correct service manuals.
