2001 Dodge Ram 1500, 2wd, 4-wheel ABS, 100k miles

Brake pedal travels close to the floor when pressed, than gets hard. Truck stops fine. Master cylinder has just been replaced along with brake lines. Brake pads & shoes are ok also. The same problem existed prior to these parts being replaced.

The entire system has been bled more than once, mc was bench-bled prior to installation - there is no air in the lines.

There is no leaks in the system - mc fluid reservior has the same amount of fluid as when I replaced it 2 months ago.

Rear brakes have been adjusted to where shoes barely touch the drums.

I've noticed similar threads with people having exact same issues, but no solution found.

Please help - thanks!

 

It sounds like they weren't bled properly.
Start with the fronts, and work your way to the back.

Get the proper sized clear tube and a container with some brake fluid in it.
Put the tube over the nipple, loosen it, and have your helper slowly push the brakes to the floor and hold them there.
Tighten it back up, and they can let off the brakes. Loosen it up again, push to the floor and hold, tighten it up, and repeat 4 or 5 times for each cylinder, until there are 0 air bubbles, and you are sure no air is trapped in the lines.

Keep the end of the tube under the brake fluid in the container, to avoid the possibility of sucking in any air ... And keep an eye on the brake fluid level in the MC, refilling as necessary.

Maybe you've done all this, I'd try it again. If theres air pockets trapped in the line, it can take some doing to get them out.
Keep in mind also that cylinder leaks can be elusive and hard to spot, keep an eye out for any small leaks dripping down the rear of the drums.

 

negtive... wrong,

when bleeding brakes you start with the wheel farthest from the master cylinder, and move closer...

 

How long have you had it? Did it do that from day one when you got it? It kinda sounds like you have the wrong mc.

 

I agree with xray. bleed the brakes again. However, to give you piece of mind, with the truck turned off, pump the brakes to build up pressure and make the pedal rock hard. Once it does, hold the brake pedal down and turn the truck on. If the brake goes to the ground, then your brake booster is fine. If not, then you have a problem. I still think you need to bleed the brakes again. When I changed my MC, it took a while to get ALL the air out.

 

hows your brake booster?

 

True that, thats what I was thinking and I stand corrected.
Also might be advisable to put a 2x4 under the brake pedal, to stop if from traveling too far.

 

I've had the truck for 2 years, and it's been doing this from day1.

The brake booster is fine.

MC was bought from autozone & is identical to the factory one that I've replaced. The problem existed prior to MC replacement - in other words, replacing MC didn't change anything.

The truck stops fine - I can engage the ABS by stepping on the breaks hard enough & eventually lock the wheels.

I just don't like the long pedal travel.

 

mine did the same thing....then i adjusted the rear brakes and now its fine