[steven.wright]

I have a similar feel in my brakes, and the abs and slip lights are on.

Did you find your problem?

Abs and slip light together you should check your wheel bearings if you are having a week feel in your brakes at the same time. Bearing wobble will also push the piston/pad back in the bore and use up pedel travel presenting itself as a soft pedel.

 

[Clint]

Any spongy or mushy pedal is always a hydraulic issue, the pads stop the vehicle but don't compress as they are hard surfaced items.
Unless synthetic fluid is used brake fluid absorbs moisture and NEEDS to be replaced after a period of time but most people never bother to do it. Once you change the fluid you'd be very pleasantly surprised at how much better the pedal feel is.
My guess is back feeding the old fluid at pad change affected the master cylinder at worst or at best affected the calipers but a fluid replacement will correct this issue.
There is a HUGE difference between maintaining a vehicle and doing repairs when something breaks or wears out. The average vehicle owner only does what they HAVE to do.

Clint

 

[msk59]

@msk59 did you ever get a resolution to this brake issue?

No after installing OEM front pads, the brake improved about 10 percent and during my move I hauled u-haul trailers about twice and the brakes worked the same. I think there is air somewhere in the abs system, since initially I did not bled the system properly.

Yes I know about cracking the bleeder open when pushing the caliper piston back so the crud can get out and not go back into the system. I also bled all brakes until I see clear fluid.

 

[2013Pro4X]

You guys know you are supposed to crack the bleeder to let the trash out as you press the piston back into its bore, right? Pushing nasty corroded crappy fluid up into the abs pump motor and the master cyl is just not good.

I just did my pads/rotors, and I did not know this.

Even though I've done 10 or more rotor/pad changes on other vehicles, I still made sure to read and follow the FSM for the fronty before I did it, and the FSM makes no mention of this.

What you say does make sense though, hopefully I have not done any damage.

I'm going to do a full bleed and replace of the fluid shortly, since I'm probably due anyway at 35K and 2 years.

and since I have a horrendous history of being a lousy bleeder (or having a bad assistant) , I just ordered this:

0117 Black Label Ford / Import 3-Tab Power Bleeder

so hopefully I can do a nice job this time on this vehicle.

 

[AndysLog]

yea it makes sense for sure and sounds like good practice. over the last ten years on im honestly going to guess in the nearly 100 different vehicles or more ive never popped open the lines as i walked the piston back.
and ive never seen anything in any FSM recommending me do so.

i do think its a good idea for sure. but you would still need a bleed in my eyes once its done. unless you are a robot that can push the cylinder back and open and close the valve and perfect moments.

 

[Dark Night 18]

You guys know you are supposed to crack the bleeder to let the trash out as you press the piston back into its bore, right? Pushing nasty corroded crappy fluid up into the abs pump motor and the master cyl is just not good. If your caliper slides are not corroded solid you just set a pan under the caliper, crack the bleeder and pull the caliper so the piston retracts. Try it. You will see big chunks of black nasty crap in dark fluid. Then change pads like normal, clean and properly lube sliders, reassemble, refill master cyl, replace cap, pump brakes slowly and firmly till you contact pads to rotor, then refill master to the fill line. Then dont touch the fluid it is set so that when it looks low your brakes are almost worn out, the sensor is there to tell you it is low.

When people complain of a soft mushy pedal but the brakes are known air free (properly pressure bled) almost always you will find sticky slides, or a combination of sticky slides and rotor surface runout that pushes the pad/piston back, then that uses up pedal travel so the driver feels that the pedal is soft with poor stopping power.

If your rotors have runout, are you talking about warped rotors?
If that's the case you WILL feel the pads moving in and out as a pulsing in your pedal.

Oh and Clint is 100% correct about moisture in the fluid.
Good call. ?

 

[mtyler11]

I just did my pads/rotors, and I did not know this.

Even though I've done 10 or more rotor/pad changes on other vehicles, I still made sure to read and follow the FSM for the fronty before I did it, and the FSM makes no mention of this.

What you say does make sense though, hopefully I have not done any damage.

I'm going to do a full bleed and replace of the fluid shortly, since I'm probably due anyway at 35K and 2 years.

and since I have a horrendous history of being a lousy bleeder (or having a bad assistant) , I just ordered this:

0117 Black Label Ford / Import 3-Tab Power Bleeder

so hopefully I can do a nice job this time on this vehicle.

found this write-up over at the Z-car site... bleed your brake fluid using motive power bleeder 0117

I like the look of that bleeder... a bit pricey ($75) but the Mityvac kit is $40-50 so all's relative... And if you can get a few friends to go in on it with you or get them to give you $10 plus fluid per change... I know I'd give a friend $10 to change my brake fluid

 

[2013Pro4X]

found this write-up over at the Z-car site... bleed your brake fluid using motive power bleeder 0117

I like the look of that bleeder... a bit pricey ($75) but the Mityvac kit is $40-50 so all's relative... And if you can get a few friends to go in on it with you or get them to give you $10 plus fluid per change... I know I'd give a friend $10 to change my brake fluid

Thanks for the link! The comment in step 8 about needing at least 13psi to open the abs valve is good info (and new to me), not sure if that is the same for the fronty, but that is a good reminder to keep checking pressure and keep it at 15 psi.

 

[mtyler11]

Found the Motive on Amazon, for those who are interested, for $55. Comes with 2 adapters, says it'll fit Nissan & a slew of others... power bleeder

 

[steven.wright]

Opening bleeder valve is considered a best practice. Many shops require it. Some after paying for abs pump motors, most just do it since it is easy, efficient, fast, and saves come backs. You immediately know if the slides are frozen. It just works great. Air doesn't just jump in the system. It is a smooth process, break the bleedee loose but still sealed, twist the quarter inch ratchet while pulling firmly towards you on caliper to a stop. Twist ratchet to tight. Remove lower slider bolt. Twist caliper up, remove pads, clean seating surface, slide caliper off upper pin, clean and lube slides, reinstall pads and go to the other side. Our policy was do it this way here or however you like somewhere else. Comebacks cost to much money, and time. Say the OP paid someone to do his truck and he had this problem, would he keep paying or would the shop lose money. I know some shops are crappy but most are very professional.

 

[steven.wright]

Yes you will feel runout. Even very small amounts, some people never said a word about what I thought was tooth rattling. Once I was able to explain the reasons for on car brake lathes, and proper tourqe on wheels they were my best advertising, the words smooth as glass and like silk is how it was described.

 

[adamjt]

Has anyone solved this yet? I had the same thing happen. Must have flushed to 32 oz bottles of brake fluid through the system. Didn't drive the truck for a month later on and now it feels really really spongy to me.

 

[still truckin]

No, I didn't resurface or replace the rotors. The rotors were in great shape. I have done hundreds of brake jobs and never had a pedal go from rock solid to spongy as hell just by put front pads on even if the rotors were a little imperfect.

I pressure bleed the whole brake system yesterday with no change in the brake pedal travel. I KNOW there is NO air in the brake system. The pedal is rock solid and feels great with the truck not running. There is no bleed off in the pedal holding pressure on it with the truck off but as soon as I start the truck you have to pressure the pedal half way down to stop the truck. Instead rock hard once stopped the pedal is spongy and I can push it to the floor.

I will drive the truck some more to see if the pads just need some more bed-in time.

I have the exact same issue. I'm at 175,000 miles. I have replaced pads and rotors on all 4 wheels 3 times. Brakes always felt good and solid. After this last time the pedal travels halfway down before anything happens and coming to a stop theres always a little lurch and squeak. No matter how I feather the pedal. I'm wondering about the Master Cylinder.

 

[Dark Night 18]

Master. Would be my next guess. However, was the pedal feel OK before you changed out your brakes? If the answer is yes it was, then your problem is not likely the master. It could be a coincidence, but I personally don't believe in coincidence. Good luck and keep us updated.

 

[mxtreme30]

Haven't read thru the whole thread so if this has been discussed then disregard... I think where a lot of people get into problems with changing then bleeding brakes is when they use the old school method of pump pump push to floor. Well after so many thousands of miles with master cylinder only going a set amount of distance each stroke then all of a sudden you require it to double the stroke which takes the seals past the normal wear pattern it is possible to damage piston seals. Kinda like if you rebuild an engine with new bearings and rings but fail to bore and hone rim of each cylinder. As soon as you fire it up and rev the piss out of it you'll more than likely shatter the rings or seriously screw up the lands. It's best to either vacuum bleed or pressure bleed using master cylinder adapter. That way you don't ever go past the normal wear pattern of master cylinder piston.

 

[bajasam]

or you can just place a piece of 2x4 under your pedal so it doesn't go to the floor when pumping pedal.