Hard brake pedal

[amcilwain]

I have an intermittent hard brake pedal. It happens at least once every time I drive it. If I really stand on it and push thru the hard part it gets normal. Or I can let off and press again and it will be normal. It never goes to the floor bits either hard or normal I've already pulled the ABS fuse and it made no difference. Everything I've found here says booster. Is this correct?

Sent from my piece of crap salt water corroded iPhoneusing IH8MUD

 

[bmw635]

Just went through this yesterday. The pedal begin with same sympton a week ago then got worse until it lost total vaccum. Changed check valve didn't help so I changed the booster.

JUST FYI, you can tilt the booster toward fender before pulling out so it'll clear the intake.

 

[mdawg]

Piling on - I am seeing this symptom now as well: intermittent hard brake pedal with diminished braking power. If I depress the pedal again, it goes away, but it now seems like the pedal is traveling farther before the brakes engage. After about 10 to 15 brake cycles, the hard pedal will return.

Also, when engine on and I depress the brake pedal I hear a "hiss". Sounds like air being pushed from the brake pedal. I tested the operation of it according to the FSM, and it seems like it is following the proper operation outlined.

I did bleed the brakes last weekend (thinking it may resolve the hard pedal issue) and it seems to have gotten worse.

Sounds like a brake booster issue, yes? Maybe replace the master cylinder "while I'm in there"?

 

[mdawg]

Saw this thread now: Brake Issue Help

Brake booster seems to be the culprit.

 

[BullElk]

I am also trying to replace a booster but can't seem to get past the hard lines, especially the one going across the top. Some have said on other theads that there was plenty of room to get the booster out but I ain't seeing it.

 

[mdawg]

Yup, I'm fighting with the booster removal now. I may try loosening the driver-side engine mount and lifting engine a little to see if I can squeeze it out.

 

[unklwedy]

It ain't the problem here, but I've seen the vacuum fitting on intake manifold get gumbed up.

 

[Azca]

Booster is difficult to get out. Go under the dash and pull the black support bracket for the pedal assembly off the firewall. Use a bungee cord to pull it away from the firewall and you should be ok.

Also make sure to check the distance from the master cylinder shaft to the booster. Adjust as necessary. I found that this was what appeared to be my spongy brakes.

 

[dan360]

Me, too.....it was the booster. Changed it yesterday. Not too difficult, hardest part was reaching the top bolts under the dash.

Toyota under dash access + fat guy = cussing.

 

[mdawg]

How did you maneuver the booster out? Straight up? Twisted some way?

For me the intake manifold is my biggest barrier to getting the booster out.

 

[mdawg]

How did you maneuver the booster out? Straight up? Twisted some way?

Answering my own question, I hope this helps others. Here is what worked for me:

1. Unmount the pedal bracket assembly from the firewall (thanks Azca!).
2. Remove the booster by pulling far side out toward DS fender.
3. Proceed in an upward-ish motion. If facing the booster, visualize shooting for the 2 o'clock position.
4. Unclip top ABS line and "gently" push the line out of the way to pull the booster out.

 

[itbrokeagain]

Me, too.....it was the booster. Changed it yesterday. Not too difficult, hardest part was reaching the top bolts under the dash.

Toyota under dash access + fat guy = cussing.

I have found in several occasions it is necessary to have hands the size of a 5 year old to do things on my 80.

Sent from my SM-G920V

 

[dan360]

I have found in several occasions it is necessary to have hands the size of a 5 year old to do things on my 80.

Sent from my SM-G920V

lol so true....or a mechanically inclined little asian wife.

 

[mobilemedic]

Had my own brake issue as well and just replaced my booster last night. Yes would be nice if I had smaller hands. I bolt on the top inside left didn't make it yet due to fat hands but rest were cake and the whole job not cracking any brake lines was about an hour. Easy. Night and day change. Had to stand on the brakes before to begin to stop. Now I about launch myself when the truck stops and I don't when I hit the brakes . Need to get used to the pedle working. Lol. Definitely not a task to fear. I scored a used one for 90 bucks shipped from a wrecking yard so donno if being exact oem makes it that easy or not(donno if non oem will be a headache)

Follow the brake lines down about 6 inches on firewall and unbolt the retainer. Then the master cylinder can be moved pretty freely and placed out of the way. Booster pretty much came out and up easy. Back in the same way. (Saying this I realize I have done an egr delete so may have way more room than others)

Glad I got it done