Replaced pads and rotors, brake pedal sinking to floor now?!?

[UniqueTII]

2003XLT. started it up, gave it a minute for idle to drop to ~900. step on brake / firm pressure. it goes about 2/3 of way to floor and holds for a few seconds then **** drops all the way to floor. release & press again ... goes all the way to the floor

curious about your statement "stopping wasn't really the issue before, either" and my experience with my brake pedal and wonder if your chasing a non existent problem

Thanks for checking! The spongy, sinking pedal is definitely a new characteristic since I changed out the brakes. I'm just saying I can get enough pressure to stop the truck. The initial bite is pretty high in the pedal travel but it takes a significant amount of additional travel to increase braking force.

I checked in my other vehicle (Subaru WRX STI) and it stays firm no matter how much pressure I apply. My wife's Odyssey, however, goes to the floor fairly easily. To be fair, it needs front brakes soon.

EDIT: Also, I should add that I never get firm pressure on the first push. It goes right to the floor unless I pump it 3-4 times.

 

[UniqueTII]

Short additional update: I went out to bed the brakes per Powerstop's recommendation and lost most of my pedal pressure once the brakes got hot. It got to the point where I'd have to go all the way to the floor to get the truck to slow down and the truck started pulling to the right, although that could have been due to the road crown. After letting them cool down for a few miles, I had to slow down for a red light. I still had very little pedal pressure and had to go nearly to the floor to get any feedback.

I'm going to do some more troubleshooting before contacting the dealership again. I'll pinch all 4 lines to see if that changes the behavior at all.

 

[Plati]

Short additional update: I went out to bed the brakes per Powerstop's recommendation and lost most of my pedal pressure once the brakes got hot. It got to the point where I'd have to go all the way to the floor to get the truck to slow down and the truck started pulling to the right, although that could have been due to the road crown. After letting them cool down for a few miles, I had to slow down for a red light. I still had very little pedal pressure and had to go nearly to the floor to get any feedback.

I'm going to do some more troubleshooting before contacting the dealership again. I'll pinch all 4 lines to see if that changes the behavior at all.

btw ... i never really believed that this problem doesn't exist for you.
what a pain in the A$$ it must be for you. Sorry Dude - seriously
If my 2003 was doing that I would launch it down the bank into Irondequoit Creek

 

[Plati]

OK ... this is really humorous. I just went out to drive my 2003 to The Depot. Brake pedal goes right to the floor. Pump it couple times, same. Put in reverse ... NO BRAKES or very little. I was able to stop it, just barely after a few feet. Crap on driveway!!! Gotta be brake fluid I would guess. No brakes.

I can drive my 2014EL until I get the 2003 repaired. I'm gonna take the attitude that you helped me out by precipitating a failure in a safe location (driveway) rather than out in traffic where it would SUCK. TFF



Once I look at it, I'll post up what broke

 

[UniqueTII]

btw ... i never really believed that this problem doesn't exist for you.
what a pain in the A$$ it must be for you. Sorry Dude - seriously
If my 2003 was doing that I would launch it down the bank into Irondequoit Creek

I'd do that but it's too flat here in Iowa. lol. I love the Irondequoit area! I drive through there going between my dad's place in Rochester and my sister's house in Oswego.

 

[UniqueTII]

OK ... this is really humorous. I just went out to drive my 2003 to The Depot. Brake pedal goes right to the floor. Pump it couple times, same. Put in reverse ... NO BRAKES or very little. I was able to stop it, just barely after a few feet. Crap on driveway!!! Gotta be brake fluid I would guess. No brakes.

I can drive my 2014EL until I get the 2003 repaired. I'm gonna take the attitude that you helped me out by precipitating a failure in a safe location (driveway) rather than out in traffic where it would SUCK. TFF

View attachment 38270

Once I look at it, I'll post up what broke

Whoa, glad you found that safely! One of the worst mechanical failures I've had was a front control arm breaking in half on my old Mazda. Thankfully it happened at about 5 MPH in my apartment parking lot, not traveling highway speeds. Very lucky!

 

[Plati]

......Once I look at it, I'll post up what broke

Yes my superhuman leg strength blew out the 99% corroded front passenger steel brake line. I had already replaced the 2 steel lines to the rear so now I will do the 2 to the front. Need to do a couple other things at this time so a few jobs to do on the BEAST to keep it on life support. The flexible line on the driver side is original so I will do that at the same time since wrenching it is sketchy with all the corrosion. I hate corrosion. I could probably skip the driver side steel and flexible lines ... but thats like driving past a rest stop on I80 about an hour after a large coffee.

 

[UniqueTII]

Dang, that's one reason I don't miss living in NY! Not as much rust here in Iowa.

 

[riphip]

Could be your brake hoses from frame to calipers. They do go bad inside & deteriorate. Check rockauto.com

 

[UniqueTII]

Could be your brake hoses from frame to calipers. They do go bad inside & deteriorate. Check rockauto.com

I changed the front ones already, but I'll try to see if the rears are an issue. Thanks!

 

[07navi]

delete

 

[riphip]

I also have all 4 hoses purchased to replace on mine.

 

[Trainmaster]

My 08 had spongy brakes which replacement hoses helped a bit. The brakes still tend to sink when applying pressure after a stop. When I release them and press down they come up a bit again. They won't sink anywhere near the floor but they sink none the less. I've adjusted the booster pushrod (which may not have been mentioned here but is one service cure) and it may have helped a little more. After reading these and F150 forums, I've accepted "spongy feeling brakes" as a normal characteristic of these trucks.

 

[07navi]

Mine is spongy too and I also just accepted that they will sink a bit if you press them hard. It always stops fine, especially after I flushed all the fluid.

 

[UniqueTII]

I can get used to spongy, but this is way worse than anything I've experienced with this truck before. I get almost no feedback from the pedal until I'm about at the floor.

Messing with it again tonight, I pinched all 4 brake lines and got good pedal pressure. I released the clamps on the rear lines and I'd get slightly more pedal travel but no sinking. Opening up either of the front lines would result in the pedal losing pressure and sinking to the floor. I pulled the wheels and noticed a strange contact patch on the outer passenger pad where it looked like the outer 1/3 of the pad wasn't contacting the rotor enough to clean it off. Not sure what to think of that, but the driver's side looked better. I didn't really notice anything else odd with the pads, rotors or calipers. I was going to start putting old hardware back on but I realized that I already threw away my old pads.

One thing that was recommended that I've tried before is removing the vacuum going to the booster, which results in a solid pedal. I did that again tonight with the same result, but I can't wrap my head around how a failing booster would cause this issue, but I have heard people with other makes of vehicles say that it did for them. The vacuum pump is pulling 25inHg so I don't think that's the issue.

 

[UniqueTII]

I've read about a few other people having this issue, specifically with Powerstop brakes. One of the stories I read stated that the pedal firmed up after about a week of driving, so the assumption was that the pads and rotors weren't parallel (which would make sense given the uneven wear I observed above). I went out and did a bunch more hard stops with it but haven't noticed any improvement yet.

 

[Langer]

I've read about a few other people having this issue, specifically with Powerstop brakes. One of the stories I read stated that the pedal firmed up after about a week of driving, so the assumption was that the pads and rotors weren't parallel (which would make sense given the uneven wear I observed above). I went out and did a bunch more hard stops with it but haven't noticed any improvement yet.

When I did mine, I didn’t love how the pedal felt, I thought I messed something up (this was my first brake job solo). After doing the break-in procedure, I was back to a comfortable feeling in the pedal. I know that doesn’t help you much except to confirm what you’ve already read online, but maybe try the break-in procedure, again?

 

[riphip]

I've not had any problems with my Powerstop brake setup. I have experienced a need to use the anti-lock braking system since install . Truck is 16 years old w/original calipers,MC & booster. Will change all of that at once when time comes. Accruing parts a little at a time at present.
I have already changed all the vacuum lines, etc after I bought it. Knew what kind of problems those would cause if unchecked.

 

[07navi]

My pedal goes to the floor also if I press hard for 30 seconds but has no effect on braking or stopping.

 

[UniqueTII]

Thanks guys! I did go do the break in procedure again and I think it feels a little better (or maybe I just want that to be true...haha) but it's still super easy to push it straight to the floor. Having to hold it for ~30 seconds is more like what I'd expect! I don't think it's a safety issue at this point since the brakes stop fine unless they're super hot, so I'll drive it this week to see if it keeps improving.

Not sure if I already mentioned this, but I thought about putting the old rotors and pads back on the front to test if that was the issue but I already got rid of the pads, unfortunately.