Spongy brakes after rotor/pad change

[daesonn]

Hey guys, I recently decided to do a total brake pad change and rotor swap up front after I was experiencing some warped rotor issues. Since the swap, my vibratory issues have dissipated however my brakes feel sort of spongy. Sometimes my truck seems to get away from me that last few feet, if you know what I mean. I've put several thousand miles on the truck now since the change. The brake fluid looked clear in the reservoir when I did the swap and was limited on time so I figured I would be safe not bleeding the brakes.

Do you think this is just a simple matter of air in the brake lines? I've never had air enter the brake lines on a brake pad and rotor swap on previous vehicles....

Thanks

 

[Lester Lugnut]

Assuming you have a 5th Gen 4R.

The following is from a Tacoma site, but specific models of that vehicle use the same electric master cyl setup that 5th Gen 4Rs use.

In the thread below, the poster talks about using speed bleeders. You do not need to do that. What's important to know is that Toyota was kind enough to provide an auto-bleeder function for the rear brakes. The fronts are bled using the old 2 man method.

DIY, Brake fluid flush, 4x4 - TRD Off-Road with Speed Bleeders | Tacoma World

You can find similar info here at this site using the SEARCH function.

 

[Jivewalker]

I did my rotors a while back without bleeding the brakes and had no issues. Not sure how you would get air in the lines if you didn't bleed. The only sponginess would be the first time or two you press the pedal after forcing the caliper pistons in to accommodate new pads. My money is on something else, low fluid, or something not mechanically correct in the install. Did you use OEM parts or upgrade to something else?

 

[btcsxj]

what process did you follow for bedding your new brakes?

 

[BobsTrail]

Time to do all 4, the rear is easy, front is old school or I used a Motiv vacuum tank for Mine. I used DOT 4 fluid and emptied most from the master cylinder first. Got out all the older fluid first.

 

[daesonn]

I used some how-to I found. I don't remember exactly but I was pretty confident in my work. I also greased every God damn metal-on-metal surface and still ended up with a damn squeal. I have no idea how I ended up with air in the brake like but I definitely did. Noticed air bubbles in front left side during and brakes feel much better now. Problem solved.

 

[N6WRV]

I used some how-to I found. I don't remember exactly but I was pretty confident in my work. I also greased every God damn metal-on-metal surface and still ended up with a damn squeal. I have no idea how I ended up with air in the brake like but I definitely did. Noticed air bubbles in front left side during and brakes feel much better now. Problem solved.

Be aware that brake fluid is hydroscopic. Namely, it attracts water. Since brake fluid is lighter than water, water and dirt in the brake system will tend to accumulate in the wheel cylinders. Brake bleeding will clean the bad stuff out.