Squishy / spongy brakes

[MikeinNH67]

I took a look around and didn't see much for hits on this. My brakes all around including calipers have been replaced within the last couple years. All still look good, nothing sticking closed. The last couple months the brake pedal feel has gotten progressively spongier, like 3/4 the way down for the pedal before they really grab. If you give it a quick pedal pump or 2 it will seem normal. I do plan on bleeding them (no time lately) but not sure how air would have gotten in there but they feel like brakes that need bleeding. I did do a visual on them all today and all the pads are thick and wearing evenly. The thing I have little knowledge on is the electronic master cylinder and if it can give these symptoms. I do hear it run when pressing the brake. Just curious if others have seen anything odd like this with that master cylinder. I will post progress on this for future folks.

 

[rdruss]

Watched a YOUTUBE on this recently, check all your slider pins make sure they are free and well greased.

 

[message]

Brake fluid should be clear, if it is not, time to flush it in my mind.
As brake fluid is hygroscopic it absorbs moisture rather quickly thus shortening it's lifespan. The general recommendation is to flush brake fluid every 2 years or 30,000 miles. I flush mine every 2 years.
Here in the Midwest an indicator of moisture in the brake lines is when it drops well below zero and your brake pedal is rock hard but not stopping you. In turn when it is hot the pedal is generally spongy when there is moisture in the fluid.

 

[MikeinNH67]

Watched a YOUTUBE on this recently, check all your slider pins make sure they are free and well greased.

The calipers are all pretty new and I watched them all squeeze the rotor when brakes are applied, it all seems to work smoothly just delayed.

Brake fluid should be clear, if it is not, time to flush it in my mind.
As brake fluid is hygroscopic it absorbs moisture rather quickly thus shortening it's lifespan. The general recommendation is to flush brake fluid every 2 years or 30,000 miles. I flush mine every 2 years.
Here in the Midwest an indicator of moisture in the brake lines is when it drops well below zero and your brake pedal is rock hard but not stopping you. In turn when it is hot the pedal is generally spongy when there is moisture in the fluid.

Brake fluid is not too old as it has new-ish calipers and brake lines. Hopefully the weather will be good enough to try bleeding on Saturday.

Thank you both for you thoughts.

 

[AuSeeker]

I think you're familiar with the "40 pumps" procedure, but not sure if you did it when you did your brakes, if you did I would try it again before bleeding to see if it helps, if not or if so be sure to include this procedure when you do bleed the brakes.

Here's link to a topic very similar to yours except he didn't have a spongy pedal just brake pedal going down to far, he tried it and said it didn't help but wasn't sure if he did it right and was going to try again but never posted an update of the second try,I posted a link to another topic that has a PDF that explains how to do the procedure, my post is #3.

Brake Pedal travel question

 

[MikeinNH67]

I think you're familiar with the "40 pumps" procedure, but not sure if you did it when you did your brakes, if you did I would try it again before bleeding to see if it helps, if not or if so be sure to include this procedure when you do bleed the brakes.

Here's link to a topic very similar to yours except he didn't have a spongy pedal just brake pedal going down to far, he tried it and said it didn't help but wasn't sure if he did it right and was going to try again but never posted an update of the second try,I posted a link to another topic that has a PDF that explains how to do the procedure, my post is #3.

Brake Pedal travel question

I did try it a couple times and you can hear something change on one of the higher pumps, maybe a click or similar. It seemed to help for a couple stops but then would go back to the same issue. I will print the directions and add them to my bleeding procedure as I don't recall if I did it when the calipers were replaced. I do have a bi-directional scan tool now so maybe I can even follow the steps that list using one.

Thanks for the info!

 

[Soneill]

I took a look around and didn't see much for hits on this. My brakes all around including calipers have been replaced within the last couple years. All still look good, nothing sticking closed. The last couple months the brake pedal feel has gotten progressively spongier, like 3/4 the way down for the pedal before they really grab. If you give it a quick pedal pump or 2 it will seem normal. I do plan on bleeding them (no time lately) but not sure how air would have gotten in there but they feel like brakes that need bleeding. I did do a visual on them all today and all the pads are thick and wearing evenly. The thing I have little knowledge on is the electronic master cylinder and if it can give these symptoms. I do hear it run when pressing the brake. Just curious if others have seen anything odd like this with that master cylinder. I will post progress on this for future folks.

Hopefully this is not the case for you but..... I used to sell used cars and the one time I dealt with this on a 4th gen, we had to replace to whole booster assembly. We sent it to the shop and they tried everything and that's the only thing that fixed it.

 

[MikeinNH67]

Hopefully this is not the case for you but..... I used to sell used cars and the one time I dealt with this on a 4th gen, we had to replace to whole booster assembly. We sent it to the shop and they tried everything and that's the only thing that fixed it.

I hope that's not the case, thanks for the info.

 

[MikeinNH67]

Well I spent a couple hours on this issue today to no avail. Bled the system per the process with the scanner, didn't see any air. Compressed the rear calipers one at a time with my caliper tool, no change. They are still very squishy, may even be slightly worse. I hear the pump run and stop as it should, I hope it's not that unit.

I looked at the fronts again and did notice the passenger side inner pad is worn more than the rest. Also the driver's side inner seems to back off a bit as I can see light between the rotor and pad. Maybe a sheet of paper thickness. I'm thinking about replacing the calipers and pads to see if that helps but they are only 3 years old I think. Kinda pricey to shotgun. Maybe I'll try to clamp each one fully open to see if that helps to narrow it down but I ran out of time for today.
:hurt:

 

[MikeinNH67]

spongy brake fixed

I spent some time today looking at why I have the gap on one side mentioned in above post. The pad with the gap was frozen in place in the caliper. It looked fine until taken apart.

I pulled both sides completely apart, removed the rust and reassembled with lube on the proper parts. The pedal feels normal again. These were mid-priced coated rotors with Akebono pads, maybe 4 years old and 30k. All but one pad is still quite thick. The rotor that pad ran on was rusted pretty badly and I think wore it prematurely, inside so hard to see. I knocked all the scale off the rusty rotor. Both rotors have lost a decent amount of thickness but it still brakes super smoothly with no pulsation. I may go to the Gen5 brake setup in the fall but for now it's good the way it is.

Thanks for the replies!