2010 CX-9 - New brake booster and now brakes feel squishier than before?

[LordJezo]

Brake booster failure like main others with this model and year, I was unable to stop and the car has been sitting in the garage for a while. I had someone come over and replace it because with how it was I was afraid to even drive it. I was out of warranty and extended warranty since its a 2010 with 140,000 miles on it.

So now I can stop again, the brake pedal moves again and the car is able to stop. Now though the pedal has to be pushed much farther down to get the car to stop. It will stop the car and slam everything dead if I hammer on it but it seems like I need to push more to get the same level of stopping power. I don't think its my mind playing tricks on me but I cant confirm or deny anything since its been a while since it was working right.

Now that I can drive it is it worth taking to a mechanic to have them see what's going on? I don't even know how to describe it other than I was expecting the sensitivity to be a little higher so I could push the pedal less and break more. Does that make sense?

 

[rowlands57]

Did the installer completely pressure bleed the brake system? It really should be done whenever a brake system is 'opened'. You may have some air in the lines and that will give you a softer pedal.

I'll also say that I was never impressed with the brakes in my 2012. This is the first vehicle I owned that made me plan my stops like I was dragging a trailer with no brakes. They are a very weak spot in my opinion.

 

[LordJezo]

Did the installer completely pressure bleed the brake system? It really should be done whenever a brake system is 'opened'. You may have some air in the lines and that will give you a softer pedal.

I'll also say that I was never impressed with the brakes in my 2012. This is the first vehicle I owned that made me plan my stops like I was dragging a trailer with no brakes. They are a very weak spot in my opinion.

He said he did, told me he bled the system and got the air out, but as a regular joe how can I confirm that?

 

[rowlands57]

Hold the pedal at the bottom of travel with even pressure for a few minutes. If it stays in place at that point you should be OK. If you have air in the system it would not be uncommon for the pedal to sink to the floor.

I 'think' you may be OK. As I said prior, this vehicle does not have the best braking given it's weight.

 

[PTguy]

Do these systems have a brake bleed fitting at the master cylinder as well as at each wheel? All must be bled, and in the correct sequence, usually starting with the brake farthest from the master cylinder and working in sequence to the one closest to the master cylinder.

Does the brake pedal feel spongy? If so, does it get firm after you pump it a few times? These are indications of air in the system.

 

[LordJezo]

Turns out it was air in the system and the brake fluid was low. I did the hold the pedal test mentioned and also the keep pushing it a few times to see if it gets tighter test. Both of them happened so took it to a local shop.

$123 later they bled the system the right way, filled the brake fluid the right way, tightened some stuff up in the engine compartment, and now its back to braking as it should have been. While they are not the tightest brakes as mentioned I was basically having to put the pedal to the floor to get it to stop. The brake booster was fine, it was just the other parts around it were not.

One problem solved! Now back to fixing the windows in my other threads...

 

[njaremka]

My first thought was air still in the system. Glad you found the issue.