I need to replace the master cylinder brake on my 1988 Grand Marquis
I just recently had a brake line break, well I think it broke, the pedal just kind of felt a push like it broke something or soemthing to that effect & almost went to the floor then graudally I lost brake fluid & brakes were not working since no pressure. I replaced both front & middle brake line & bled them & made sure everything was tight but still leaking fluid & no pressure at all even with fluid now. I don't know what to do, someone I know says its the master brake pump thingy. So how do I replace that??? HELP!
My car has 23 miles.
My car has an automatic
Experienced mechanics share their insights in answering this question :
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.
How to Identify and Fix Common car Problems ?
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The warning signs you might need to replace this essential component are: Your brake pedal feels spongy or goes to the floor, brake fluid is leaking or looks dirty, your check engine or brake warning light comes on, or your car “weaves” when braking. If your master cylinder fails, your brakes could fail.
The classic symptom of a failing master cylinder is a brake pedal that “dives” or sinks slowly to the floor while pedal pressure is being applied. Another sign to look out for is any leaks around the master cylinder. If a seal is worn out, it may leak past the seal and onto the pushrod that attaches to the brake pedal.
After you change your brake/clutch master cylinder kit or replace the master cylinder assembly, you must bleed air/fluid to prevent `trapped air` in the system after installing. There would be an `air pocket` in the line.
Like all mechanical and hydraulic devices, the master cylinder will eventually wear out. Depending on use, the typical master cylinder might last 60,000 to 200,000 miles. Highway commuters use the brakes less often than city taxis, for example, so their master cylinders tend to last longer.
Master cylinders should last between 70,000 and 110,000 miles. They could last forever, but they have rubber seals that wear out over time. A bad master cylinder compromises your vehicle`s stopping power.
There is also a deeper hole for the brake pedal push rod. Now you can use a manual brake master cylinder to operate power brakes but not vice versa. Power brake master cylinders have a larger piston bore diameter and are not able to supply the fluid pressure required to operate a manual brake system.
If your master cylinder is underperforming, you may not need to replace the entire cylinder. A master cylinder kit will allow you to replace and upgrade the piston, seals, snap ring and the dust boot.
Use a screwdriver to press and hold the plunger in the rear of the master cylinder. The plunger should be very firm, if not immovable, past a few millimeters. If the plunger keeps moving in, this indicates a fault of at least one of the internal seals.
A bad master cylinder can cause your brakes to fail, which can be extremely dangerous. If you`re experiencing any brake problems, make sure to take your car to a mechanic right away to have it checked out or change the master cylinder yourself.
Brake Master Cylinder Replacement vs Repair
After a few years, the seals in your brake master cylinder can wear out and start to leak. It is possible to repair this type of leak instead of having to replace the entire cylinder. If, however, your master cylinder is broken or is faulty, you should replace it.
Bench bleeding is especially useful with new master cylinders. It`s a great way to get air out of the cylinder itself and begin your brake bleeding process quickly and easily. You can get bench bleeding kits from any number of places, but we picked ours up at Classic Performance Parts when obtaining a brake kit.
This pressure travels from the master cylinder, through the brake line, and acts on the brake caliper and brake rotor. However, if air bubbles are in the brake line, hydraulic pressure is reduced, making your entire braking system less effective and your vehicle more difficult to control.
Cause: Chronic master cylinder failure due to fluid leaking past secondary seal in the master cylinder bore. A defective master cylinder pushrod seal in the power brake booster allows vacuum to draw fluid past secondary seal of the master cylinder. Solution: Replace both master cylinder and power brake unit.
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.
It can take between one and four hours to replace a brake master cylinder depending on your skill level and the type of vehicle you`re working on.
A 1” master cylinder creates 127.4 PSI as compared to a 7/8” master cylinder which is 166.7 PSI based on your foot making 100 pounds of force at the master cylinder. It is important to consider that the smaller cylinder makes more pressure but the smaller bore will move less fluid.
All AP Racing master cylinders have their part number, nominal bore size laser marked on the body together with batch codes. This allows full manufacturing traceability.
Look inside the master cylinder.
The brake fluid should be up to the “Full” line on the side of the cylinder or within 1⁄2 inch of the top of each chamber. If it isn`t, buy the proper brake fluid for your vehicle and add it until the level meets the line.
Use a screwdriver to press and hold the plunger in the rear of the master cylinder. The plunger should be very firm, if not immovable, past a few millimeters. If the plunger keeps moving in, this indicates a fault of at least one of the internal seals.
Yes master cylinders can fail without leakage, the clutch master cylinder has a piston inside and there are separate channels for hi-pressure line and return(low pressure) line and their location in the cylinder differs for manufacturers.
A failed master cylinder can cause a low or spongy brake pedal but generally does not make any noises. If however you hear a loud hissing sound when the brakes are applied, the power/vacuum brake booster may have a vacuum leak.
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.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
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.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
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.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
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.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
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.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
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.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
EPC light on 2004 Jetta. Code said brake switch faulty, but brakes lights worked. Replaced brake switch, now no brake lights.
ANSWER : Hi there. The first thing that pops in my mind beyond of what you have listed is perhaps the electrical harness attached to the brake switch. Perhaps the harness itself is damaged or you have an exposed wire, loose ground wire somewhere. You might want to have a professional mobile mechanic come to your location and complete a brake lights not working inspection to help you diagnose this issue.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
I have an 05 Grand am and I just replaced the booster master cylinder calipers and lines and still have no brakes why?
ANSWER : Hi there. What you are describing could possibly be caused by a leak somewhere in the master cylinder. When the master cylinder is leaking, the pressure in your braking system will dissipate rapidly. As the pressure in the system goes, so too does the pressure in the pedal. However, this could be multiple issues as diagnosing a brake pedal issue is very difficult without being there to complete a brake pedal is not solid inspection. You might want to have one of our mobile mechanics come to your location to help diagnose this issue.
Read Full Q/A … : I need to replace the master cylinder brake on my 1988 Grand Marquis
