Master cylinder needs replacing. Dealer told me fluid is leaking and making the traction light come on. Is this true?

well that is a 2 man test (PERSONS)
onE steps on brake, person 2 see leak source, (ACTUALLY)
the car dealer sells the parts, no year car told at all .
parts are last , diagnosis is first,and a full brake inspection is NOW, do not drive cars with bad brakes tow it to a shop.
the MC can like down to the ground, via firewall MC mount
mc = BRAKE MASTER CYLINDER,
if ABS CAR, IT TOO CAN LEAK AS CAN FRONT CALIPERS.
FLUID CAN SQUIRT, AND FOOL YOU SO THE 2 PERSON RULE IS IT.
TESTING, 1,2,3.

Needs to have code reset for abs by a obd2 code reader with abs or find a parts house or shop that will reset it. Brake light coming on did you bleed the master cylinder out by connecting rubber lines to ths plastic insert ******* then acuating the master cylinder til all air is pumped out of master cylinder if that was not done then you will need to bleed all brakes until air is out of system that should turn brake light off

Hi Jacki, If you are losing brake fluid it must be leaking from somewhere and the places are limited. Fluid can leak from any one of the four wheel brake cylinders, the master cylinder, the ABS pump and valve unit, the master cylinder or cracked or broken metal or flexible brake pipes. Wherever the leakage is, it must be visible and detectable, as the fluid will make the area wet, If you look at each one of the four wheels, I'm sure one will have been marked by the leakage. The ABS / Traction control are separate from the Emergency brake warning light. The latter (E Brake) warns of loss of brake fluid. Whenever you top up it will extinguish, but illuminating again when the fluid has leaked out! The ABS and Traction control warnings will come on when an electronic signal fail to be transmitted and thereby triggering a fault code. These codes will be extinguished when the vehicle is connected to a scanner and the faults are deleted from the vehicle computers memory. You will most likely find that the wheel cylinder which is leaking has contaminated the pick up sensor which sends the signal to the ABS / Traction system. It will likely need removing, cleaning and then refitting. I am very sure that if you take a flashlight and lay down, even without crawling under the vehicle, you can identify where the leakage is, and point it out to those experts who it would seem have been misleading you. I doubt the leakage will be on the master cylinder, as having two unrelated faults would seem to be stretching coincidence a little far. (But I may be wrong and two problems may have come separately together! I believe the two are related to one wheel cylinder which has contaminated a sensors, The leakage is the most serious problem, as it can leave you without brakes! have that seen to very urgently! In fact NOW!!!! Regards John

check inner side of tires for wetness,make sure no leaks at wheels,then check floor board for wetness on drivers side,sounds like bad master cylinder for brakes,or really bad brakes,need to check to see if pads are bad as all fluid will go to the wheels when pads are bad then when you replace and calipers are squeezd back the fluid goes back to resvior,have someone help you check,but could be bad brakes,sound like bad master cylinder though.

The Golf has a hydraulic type clutch, it works off a master cylinder and uses a slave cylinder to engage and disengage. It has a hydraulic line, hose and tubing. Have you checked the fluid level in the master cylinder? Are there any leaks under your car? Often the seals go out on the slave cylinder and the fluid bypasses not allowing any pressure to build, resulting in a soft pedal that goes to the floor. Fill the master cylinder with approved fluid and "pump" the pedal by hand, you should start feeling some pressure build. Then check for leaks. if that is not the problem, you will need to troubleshoot the clutch for pressure plate problems or possible faulty master cylinder. Good luck, i hope this helps.

mcdevito75 here, True a bad Master cylinder but you can"t rule out a major leak, look carefully for brake fluid leak, also chek fluid in master cylinder if low, fluid going someplace, have the shop check it out.

yes it must be replaced very true.

I will assume you know there is a button on the dash to turn the TCS on and off. Make sure that button has not been pushed. The brake light can be on due to worn brake pads or low fluid level. If the TCS is not turned off then I suggest you take the car to a trusted mechanic or to your local Honda dealer and have it looked at. It takes skill, knowledge, and the proper tools to diagnose this type problem. It can be many things including a sensor, and you can spend lots of money guessing. Spend the money to have it repaired by someone who knows what they are doing. You will be money ahead and have it done right the first time.

The master cylinder supplies the pressure to the brake fluid that travels between the maste brake cylinder resevoir and the brake caliper pistons (through the brake lines. If the master cylinder fails there will be insufficient compression of the brake fluid to make the calipers operate as designed. Leaks in the brake lines and/or cylinders is a possibility, and unrelated to functionality of the master cylinder. Also, pistons located in the brake calipers can form a corrosion ring on their inside walls if there is breakdown in the brake fluid or moisture that gets into the lines. Operating the vehicle when there is insufficient brake fluid in the master cylinder resevoir can also lead to air getting into the brake lines, causing bad working brakes. Air compresses more than brake fluid, and the master cylinder isn't designed to compress air in the brake lines. Sounds like a bad case of "lack of maintenance", as opposed to bad advice from the mechanics. That said, there's no excuse for bad installation. But, it's tough to improperly install a brake line since they are nothing more than hollow metal tubes. There should be no rubber connectors installed in the brake lines. When bleeding the brake lines one must remove all of the trapped air before you will see any fluid appear. If the valves in the master cylinder are not properly operating the master cylinder will not allow the brake fluid to get into the brake lines.

Hope this helps.

The red brake light is the key here. That usually indicateds a hydraulic problem. Check you fluid level in master cylinder and see if it is low. Also the level indicator sensor there in the master cylinder maybe sticking or corrioded. If ABS sees the red brake light it will shut off and turn on the ABS light,also traction control would be disabled as well.