Hi everyone, have a small issue with my 2012 ISF; hopefully someone can help me solve this.

Symptoms:
1. I am a new owner of the car so I am not 100% sure on how stiff/ spongy the brake pedal should feel; however, it does feel spongy compared to other car I driven.
2. Sometime the braking distance is inconsistent. I am not talking about race track braking, but just day to day driving. Once every few months, there will be one time where when I depressed the brake pedal, the car does not seem to be slowing down until I depressed the pedal further than usual.
3. After I park the car overnight, everyone morning the brake pedal is always stiff. Impossible to depress fully, but just enough that the car recognized the pedal is depress for me to start the car.

I did not think these were big issue when I bought the car back in September 2018; but thinking about it now, it might be best to fix this.

I also did some research myself and found a few potential reason for these symptoms. Please correct me or confirm it for me if you seen these issue before.
1. Brake fluid needs to be changed. Maybe some moisture got in to the systems hence the spongy feel.
2. No idea on the reason, but possibility due to 1 & 3.
3. Possible vacuum line leak. Need to replace vacuum line.

 

Sounds like a small leak in in the PB vacuum storage canister.

Lou

 

HI Lou,

Do you think the canister is the issue for all 3 symptoms? Would you happen to have the part # for this?

Thanks in advance!

 

Stiff Brakes: https://www.clublexus.com/forums/is-...or-awhile.html

Unless you depress your brakes several times after you shut down the engine, you may need to replace this ~$30ish part. I did it and it resolved mine.

 

This has been discussed in a number of threads. If you want to try cheap, you can clean the booster check valve with brake cleaner first. A few have tried this and it worked a little longer, but ultimately, you'll end up replacing the check valve. A few owners have had the booster itself fail. That's a much bigger job to replace, but it is also a possibility.

 

First thing first, is the brake system flushed and fluid replaced at all? What is the color of fluid?

 

No, not first thing first at all. The brake booster check valve has been problematic for a long time on the 2IS platform.

 

This is my daily and I do plan on keep the car running in optimum condition for a long time. Definitely want to have the booster check valve replaced.
Is this doable without a car lift? Or is there service manual online so I can take a look myself?

Thanks!

 

Thanks for this. I've been having the same problem, but I didn't know it was a problem, just sort of figured.

 

It's dead easy to get to. You just have to remove the plastic engine cover up top on the driver's side and you can see the valve in the brake booster with a big fat hose on it. Pull the valve out after pumping the brakes to be sure there is no residual vacuum, pull the valve off the hose, stick the new valve on the hose then into the booster. Might take 10 minutes if you work slow.

 

 

Although the explanation in the previous post was easy to understand. Picture worth a thousand words.

 

Just an update on this fix.

I changed my brake fluid and changed the brake booster check valve 2 days ago. The brake is still stiff after parking over night; however, it is not as "extreme". I have never sit in a new ISF before so not sure if this is considered normal.

The shop that I went to did suggest that maybe I should change my brake pads based on the first and second issue I have. Since I do not know what brake pads the previous owner changed to, I kind of agree that maybe these are only economical pads hence impacting the braking feel of the car.

I will be upgrading my tires in the summer and maybe brake as well. Anyone has any recommendation for brake pads?


ps. Please don't hate me for going through a shop for this 10 minute fix I prefer to use this small fix to find the shop that I can later trust for bigger job

 

 

I struggled for two years with brakes that felt like there was air in the fluid on the wife's Scion tC. I replaced the rotors and pads with OEM and all the issues disappeared. It wasn't the cheapest solution, but it worked for sure.