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BBBRRRRRTTTTT
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Discussion Starter · #1 ·
2016 f250 53k miles.

If i pump the peddle it firms up but only for that event. 80+ mph my peddle feels great. After i bleed the brakes, peddle feels good for a while then slowly tapers down to soft again.

Pads have plenty of life.
Cant find ANY leaks and i dont seem to be losing any fluid.
The dealer repaired the pass front hard line many moons ago so i replaced it (thanks ford engineers) as well as the driver side front hard line.

Ive also bleed the brakes with the truck running.

If i slam the peddle, brakes well but if i stop like normal it sucks.

Only other guess i have are the rubber lines or abs module is losing its pressure.

Any ideas?
 

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Have you inspected the firewall for leakage from the master( as if you can see in there)


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If you haven’t yet; I would start with full fluid swap. BF is hygroscopic and absorbs water over time. The water boils and makes a spongy pedal.

Are the rear pads OK? Mine were nearly gone and pedal firmed up after changing.
 

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06 6.0 drw 635 rwhp (retired) 08 KR build in progress
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Make sure you don’t have a pad stuck in the bracket, happens often on any vehicle. All 8 pads need to be free in the bracket. Also make sure the caliper pins are free as well.
 

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BBBRRRRRTTTTT
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Discussion Starter · #6 ·
No fluid coming into the cab.
Its as clear as day (ive run several bottles through bleeding). Front and Rear pads have tons of life left.
I can check the pads and pins i suppose. Im not getting a dragging feeling nor does it feel like the trucks fighting itself to get moving.
 

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Have you checked rotor temps with an infrared thermometer? I wonder if one may be hotter, due to any of the possible problems mentioned.


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I'm one for replacing the caliper brake lines with stainless steel versions.

Are you making any steering inputs while trying to brake??
 

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BBBRRRRRTTTTT
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Discussion Starter · #10 ·
Ill check when i go to the gym, truck doesnt really pull. I did think of glazing but figured id still have good pedle pressure though.

Not specifically. Doesnt matter if im turning or going straight.
 

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BBBRRRRRTTTTT
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Discussion Starter · #11 ·
150 and 160 degreea for rotor temp. 100 and 110 for caliper temp. So good there.

Brakes were also pretty good today, so maybe i got it right. Didnt test drive it after the last power bleed. Wife was helping and said they still felt spongy, wont listen to her again lol
 

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A slow apply with a long/soft pedal, but high and firm with a quick hard apply is a sign of the master cylinder cups leaking, which often happens after a bleeding procedure if the master cylinder is long stroked during manual bleeding.

When lines are replaced there is also a good chance air has gotten into the ABS valving and accumulator, and an electronic bleed is the best way to clear that.

For brake fluid with or without water to boil you would have to do serious mountain braking. The OE brake pads combined with phenolic pistons do a good job of thermal insulation of brake fluid compared to the last century.
 

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BBBRRRRRTTTTT
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Discussion Starter · #15 ·
A slow apply with a long/soft pedal, but high and firm with a quick hard apply is a sign of the master cylinder cups leaking, which often happens after a bleeding procedure if the master cylinder is long stroked during manual bleeding.

When lines are replaced there is also a good chance air has gotten into the ABS valving and accumulator, and an electronic bleed is the best way to clear that.

For brake fluid with or without water to boil you would have to do serious mountain braking. The OE brake pads combined with phenolic pistons do a good job of thermal insulation of brake fluid compared to the last century.
I have forscan but havent found a way to activate the abs module for bleeding. If you know how, please share. There was a steady drip from the line (i kept the reservoir full and routed the new line before removing the old one).
 

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I've not used Forscan for the bleeding procedure. At work, I had bought NGS and IDS, and we used that, and I still have IDS. I haven't needed to use it, I do as follows.

When you are opening up the brake hydraulics, the better procedure is to pull the fuse for the brake lights and put a board between the seat bottom and the brake pedal, so the pedal is engaged by about an inch. Power seats are great for this. By engaging the master cylinder, you closed off the ports, like putting your finger over a straw and taking it out of water. Of course, if you are going to remove the caliper, you have to open a bleeder screw to let out the pressure. And we/I only remove one caliper at a time.

But no matter, anytime a line is open, you have a risk of fluid coming out while air is moving up. That happens with lines that are more horizontal; vertical lines seem to be fine. At least over the thousands of times we had to flip brakes.
 

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BBBRRRRRTTTTT
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Discussion Starter · #17 ·
I had the batteries disconnected.

Filled resevoir to the top.
Removed brake line at abs module and installed new one.
Went to pass. Side, new line was dripping brake fluid so i disconnected the old line and installed the new line.
Removed and installed driver side line.
Bleed brakes with truck off.
Test drove, needs improvement.
Bleed brakes with truck on, posted this post.
Drove truck and seems to be good. Not perfect but i wouldnt be afraid to tow right now.
 

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BBBRRRRRTTTTT
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Discussion Starter · #18 ·
Brakes were still good today. Guess the hardline i replaced was the culprit. Still mad its one piece though lol
 
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