macanto66

I have a brake question.
I have an 08 Jeep JKU auto with 107,200 miles on it.
With the engine running and in gear if you step hard on the brake pedal and hold it down(try to push it to the floor) it will slowly go down to about two and a half inches from the floor.
My master brake cylinder had debris in it (it looked like black suet) so I took it to the dealer, they confirmed the brake cylinder was bad and changed it out with a new one.
I picked up the Jeep and tried out the brakes. Brakes are responsive, brake nice and smooth, everything seems to be fine... except the brake pedal will still go down just about to the floor.
The dealer says that this is normal for a vehicle with 4 wheel disk antilock brakes.
Dose anyone know if this is true or not?

ronjenx

I just went out and tried mine with the engine running. Depressing the brake pedal and holding pressure on it as if making a hard stop, the pedal goes down to about 3" from the floor and doesn't sink any more. It's not solid like non-powered brakes, but constant pressure doesn't make it come any closer to the floor.

macanto66

I had to correct my post. Mine goes down two and a half inches from the floor. This is the first vehicle that I had with 4 wheel disk brakes. It threw me when the pedal goes down and then continued going down further with extra pressure.
Thank you ronjenx.
I guess it may be normal.

Mountain Man Tim

ya that sounds normal to me for 4 wheel disc brakes with abs.

macanto66

Thanks Mountain Man Tim

airforce26yrs

I think it is a Jeep thing. My WJ did the same thing and my JKU is the same way, but I call BS on what the dealers say. My 2012 Dodge Ram with 4 wheel disc and ABS has a hard pedal and does not sink too far when applying the brakes. Almost all vehicles nowadays have 4 wheel disc and ABS and I will bet most of them do not have the weak brakes that Jeep has. Jeep brakes suck.

Mountain Man Tim

if you hit the petal hard it will be firm, but if you brake lightly and keep light constant pressure the pedal sinks, thats the abs at play. if im not mistaken this is what the op was describing, but ya if you push hard the abs thinks to itself "emergency stop mode" and gives you a firmer petal, light pressure and you likely dont even engage the abs and the pedal will sink till it hits bottom point.

some folk dont remember life without abs, when you actually had to pump your brakes to avoid skids and stop faster! abs is a good thing since few people ever mastered that skill...... traction control is also handy when on road and driving in crap conditions with ice and water. the traction control off switch is nice for offroad and sticky situations.

airforce26yrs

If I hit the pedal hard and the ABS does not engage then it still goes almost to the floor. When the ABS engages yes the pedal is harder and it pulses but that is because the ABS is pumping pressure to the different wheels as necessary. My Ram is firm at all times so I still call BS. How many other people have other vehicles that have a firm pedal? Please post.

Aragorn

I just bled mine yesterday. Mine stop about at about 4.5 inches from the floor and don't fade. Just went outside and measured in the driveway.

airforce26yrs

You are lucky. Mine have faded since day one when I bought it and my WJ did the same thing. I went round and round with Chrysler on my WJ and got no where.