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DisgruntleD
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Discussion Starter · #1 ·
I'm having some brake troubles. It must have just happened over time and I got used to it, but my dad drove it and almost ran through the garage, and then I drove his and its like a night and day difference.

It's not spongy, there's no air in the lines that I could get out, I've put new rotors and pads on it, rebuilt the rears with all new hardware, one of the front calipers is new. I've bled it three times at least now, so I don't believe that's the issue, that and it doesn't pump up. After bleeding it all those times, the fluid is nice and clean and new now.

It's soft enough that I can push it to the floor, on gravel, going less than 5 mph and not lock up tires, I just roll to a stop. Going 30, same thing, to the floor, roll to a stop, 60, same thing. I can't get the ABS to kick in at all because I'm not getting enough pressure to even lock up the brakes.

I've taken it to a supposed brake shop around here, who charged me 86 bucks to bleed the brakes with absolutely no improvement and then proceeded to tell me that my new rotors were too thin and that I needed to start throwing money at it to fix it. For the record, my rotors were at the upper limit of the spec, so that's not the issue.

My next thought was the master cylinder, so in order to test that, I plugged both of the output lines and then applied the brake pedal, in theory, if the mc was bad and it was blowing past the piston, I would have been able to push it to the floor again. Well, by doing that I get about 1/2 inch of free travel, 1/2 inch of spongy travel from what little air got in before I got the plugs in, and then it stopped, I couldn't push it more than an inch.

Replace the brakes lines and apply the pedal, all 4 inches or so of travel and to the floor it goes.

I've been driving my truck as little as possible until I can actually stop safely, but I don't really know where to turn next.

I've considered installing the stainless steel brake line kit, because I know that helps give a firmer pedal, but I guess my thinking is that if I have bad line that is bulging, I would have a spongy pedal. It's not spongy at all, it doesn't pump up any after repeated pumping, it just goes to the floor.

When stopped, say at a light, the pedal doesn't fall away, but you have to hold it about 3/4 of the way in to hold the truck, and at that point you can easily push it to the floor if you want.

So I guess it could be a bad line somewhere, or it could be air in the ABS system, which I would have to take somewhere to get bled.

Where do I look next?
 

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You need someone with a snap-on scanner or the equivalent to do a brake bleeding procedure thru the computer. You dont even need to crack the lines open at all it just tells the abs pump to do some procedure.
 

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DisgruntleD
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3,822 Posts
Discussion Starter · #5 ·
You need someone with a snap-on scanner or the equivalent to do a brake bleeding procedure thru the computer. You dont even need to crack the lines open at all it just tells the abs pump to do some procedure.
That's one of the things that I've been concerned about, but I haven't found anyone to do that yet, I'm going to start calling around.
 

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Would converting to Hydroboost help this issue? I'm thinking it would some, but I still think there is something wrong downstream.
Hydroboost definitely creates more pressure but the pump would still need to be bled IMO
 

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DisgruntleD
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3,822 Posts
Discussion Starter · #10 ·
I do believe I've fixed it.

In my research I read that sometimes the ABS system needs to be reset after you've done brake work, such as new pads, that changes piston travel. They recommended getting the ABS to actuate a few times it may reset itself.

So... Last night it was raining and the roads were wet, so I was able to get my ABS to kick in, and right away it seemed better.

Today I put new pads and rotors on the front, and a new hub assembly on the passenger side. I bought a vacuum bleeder, and sucked all of the fluid out of the master cylinder that I could get, put new in, and then bled the brakes to get any air and old fluid out.

So after I did that, I went to an empty parking lot, and did 15 stops from 30 and then drove for 10 minutes without touching the brakes. On the way home I tested a few panic stops and now it locks right up and screeches to a halt. Well, as much as ABS would allow. :pepper:
 
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