Brake Feel - Takes 100% of pedal travel in order for me to brake hard enough for ABS
07-12-2018, 11:44 PM
#11
I'm having a similar problem and symptoms being vauge and soft the first half of pedal travel and firm the second half of pedal travel. I recently did a StopTech Axle Pack upgrade Front/Rear (Pads, Rotors, Stainless Brake lines) and gravity bled them initially after the swap, then 2-man pressure bled them. When initially bedding the pads I noticed quite a bit more pedal travel but was still able to activate ABS without the pedal going to the floor. Came back and did some research. tried the Billman Pedal hold trick, still soft pedal feel, so I 2-man bled the brakes again. I have the same first half of travel is super soft and long travel, then they "bite" in the 2nd half of pedal travel and grab. May be the different pads I'm not used to. I'm not sure.
What is particularly weird is that the pedal is super hard when the vehicle is off. If I press the pedal and start the car the pedal will sink about 2-3 inches. I shut the car off and pump once, and the pedal is rock hard. After quite a bit of reasearch it seems it's possible to have gotten air in the upper part of the brake system or even the master. Not sure how to fix it, but I've heard reverse bleeding (forcing fluid from the caliper into the master/reservoir) may help get the air out of the upper part of the system. I've also read that I may have screwed the master cylinder by 2-man bleeding, as it can score the piston due to dirt in the master that isn't normally a problem with regular throw of the pedal, but long presses to the floor can allow it to go past where it normally does and get into the "dirty" section of the cylinder.
As of right now it stops fine, but just has a long pedal travel. Unsure what to do next or what exactly the issue is.
What is particularly weird is that the pedal is super hard when the vehicle is off. If I press the pedal and start the car the pedal will sink about 2-3 inches. I shut the car off and pump once, and the pedal is rock hard. After quite a bit of reasearch it seems it's possible to have gotten air in the upper part of the brake system or even the master. Not sure how to fix it, but I've heard reverse bleeding (forcing fluid from the caliper into the master/reservoir) may help get the air out of the upper part of the system. I've also read that I may have screwed the master cylinder by 2-man bleeding, as it can score the piston due to dirt in the master that isn't normally a problem with regular throw of the pedal, but long presses to the floor can allow it to go past where it normally does and get into the "dirty" section of the cylinder.
As of right now it stops fine, but just has a long pedal travel. Unsure what to do next or what exactly the issue is.
07-13-2018, 06:13 AM
#12
Just use a 1 man bleeder. It works quite a bit better/faster than a 2 man bleed. Also, having the engine running will make bleeding easier.
No idea why y'all have so many issues. Maybe there's air in the ABS unit because the master cylinder was run low.
Also...
Has anyone checked pad slides and pad ears?
This is a very common cause of spongy or long travel brakes.
BTW....the 2x4 wedge method stiffens the pedal for a few days at best. Then the pedal goes back to how it was. My theory is that this method compresses the pad material itself. I don't think it does anything with air bubbles. Its not as miraculous as everyone thinks.
No idea why y'all have so many issues. Maybe there's air in the ABS unit because the master cylinder was run low.
Also...
Has anyone checked pad slides and pad ears?
This is a very common cause of spongy or long travel brakes.
BTW....the 2x4 wedge method stiffens the pedal for a few days at best. Then the pedal goes back to how it was. My theory is that this method compresses the pad material itself. I don't think it does anything with air bubbles. Its not as miraculous as everyone thinks.
07-19-2018, 12:17 PM
#13
You are running Stoptech Street pads, what did you expect? Their Sport pads are decent (marginally better than oem). Their Streets are a good step down from their Sport pads, so you are essentially running an inferior pad to oem. Switch to a better pad, and your pedal will change. There is a huge difference in pedal pressure between my Carbotech track setup and Stoptech Sport street setup (and my old oem setup).
07-19-2018, 01:23 PM
#14
Moderator
I have used it countless times throughout most of the 90s, on old difficult to bleed air-over-hydraulic fire trucks as well as box trucks and pickup trucks.
It was taught to me 25 years ago, by the truck shop owner who was 83 years old at the time. The shop still uses it to this day with great success.
The brake pedal is bricked around 4pm, and the truck is ready at 8am the following morning.
Last edited by Billman250; 07-19-2018 at 01:26 PM.
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