My breaks make a loud huming noise. not the break pads but it sounds like it is a booster problem or something to do with the abs system. the abs light stays on and the break peddle feels good in light breaking and goes slow to the floor in hard breakin. i suspect it is one of the abs sensors on the rear of the vehicle. could it be somthing else or is the sensor the most logical answer?

replace the master cylinder

When you say brake system do you mean rotors and pads or everything including the brake booster, sensors, abs. If you want a good set up go with brembo.

I think I would get the body computer scanned for trouble codes and find out why the ABS warning light is on first.
The hissing noise usually means the booster is leaking vac but if the booster was faulty the brake pedal would be hard to push.

Wheel bearings don't hum. How about a traction control or anti break lock system malfunction? Or maybe something in your powersteering system

Could be .. Low break fluid, worn brake pads, ABS malfuntion,Power Break Booster Failure.Does brake system work? ABS ? Try giong in Reverse and apply break ( make sure breaks work first in drive).Other that checking fluid and the step outlined don't risk driving take it in.Good Luck.

Hi,

New brake pads require 'wearing in' and may make a scraping sound for the first 50km or so.

Re ABS

First, I suggest you remove the PCM "Fuse" (in the main junction box, under bonnet) for 10secs, then re-insert. If you cannot find fuse, then disconnect NEG battery cable for 10secs. This will reset your PCM.

Start engine and allow to idle for 15mins (this allows the PCM to re-learn settings).

Drive car a short distance to determine if ABS light comes back on. If ABS light does come back on, then have the PCM scanned for fault codes. This will identify which ABS component is causing the (warning light) problem.

If light remains off (and the pads are worn in), but you still have scraping noise, then something else is causing this problem and will require further investigation.


Cheers,

check vaccum to break booster . Do you hear air sound when you first push break down if so booster is leaking, replace. checkfor air inABS system lookk for bleeder valve on ABS block, bleed it

This could be caused from a number of things.

Brakes shes or rotors
Worn tires uneven read wear
Bad wheel bearings.

You can rule out the brakes by 50% chance of it being this if when your driving it and you stil hear this noise without applying pressure to the break pedal. Although a pad that came off may be stuck on the rotor causing this.

Tires or more like a huming and vibrating.

Bearings are common and sound like a whirling and more pronounced as the speed picks up in the vehicle.

Sounds like you have a major vacume leak, Chk. line going to break booster. Do you hear a loud hissing or whiseling noise either comming from under the hood or under the dash especily when you apply the break? If under dash could be bad break booster, if under hood still could be booster or a break in the vacume line from engine to booster.

The brake booster/ naster cylinder is located on the firewall on the drivers side of the vehicle. The master cylinder has a resivour (sp) which has a cap and holds brake fluid. The brake booster is right behind that, the master cylinder is bolted right to the booster. The booster looks like a big circle about 10 to 12 inches round and usually 4 to 6 inches thick. It will have a vaccum hose coming off the booster and going to the intake manifold. The master cylinder with have hard lines coming off it which are brake lines. Hope this helps.