ST141 corona, brake booster no pressure

[StuRT104]

Howdi all i have recently only had front brakes because of my rear drums deciding to break from a meeting with a curb.....anyway i have now got all new drums on the back courtesy of u pull it and lines. i have bled them all but i cant keep pressure in them. There is no air what so ever in the lines. My mate said it could be my inlet leaking so i took off my manifolds and checked gasket and tightened both manifolds.still hardly any pressure, the line that goes from the booster to the inlet is sucking a little bit but my mate says that if u put ur thumb on it u shouldnt be able to pull it off, this has very little pressure. There is also no vacume lines on the car since the new engine was installed as i didnt know where everything went.

Any ideas as to why i cant keep pressure on the brake pedal?

[StuRT104]

By the way when i was running only front brakes i had enough pressure to use them and didnt have any problems, i had a bolt in the booster where the rear line was meant to go.

[StuRT104]

Anyone out there?

[StuRT104]

Cmon guys someones gotta know, someone at least reply and say they dont know anythin i need my car back on the road asap

[YLD-16L]

Driving with only front brakes........


Anyway, your description of the problem and your mates advice make internet diagnosis difficult.

There is no air what so ever in the lines.

Ok, we'll take your word for this but how do you know for sure? What was your bleeding method and how much fluid did you run through the system?

i have bled them all but i cant keep pressure in them.

What do you mean by this? Do you mean you push the pedal and it moves the pistons at all 4 wheels but the pedal just keeps sinking to the floor?

My mate said it could be my inlet leaking so i took off my manifolds and checked gasket and tightened both manifolds.still hardly any pressure

See now it's getting confusing, is the pedal rock hard when you push it (like on a functioning car when you push it a few times while the car isn't running) which means brake line pressure is fine and it's a vacuum issue.

the line that goes from the booster to the inlet is sucking a little bit but my mate says that if u put ur thumb on it u shouldnt be able to pull it off, this has very little pressure.

So there is vacuum, the peak vacuum that assists your booster comes at decelleration and is stored between the booster and check valve.

There is also no vacume lines on the car since the new engine was installed as i didnt know where everything went.

So your manifold is leaking to buggery all over the place then because it has nothing connected to vac lines and nipples?

Any ideas as to why i cant keep pressure on the brake pedal?

What do you mean by this? Because the correct answer to that question would be that you have a weak leg.
State the question correctly if you want an answer.


I would suggest that you don't fuk around with brakes if you have no idea as it's a danger to yourself and others on the road. Get it sorted out by a professional, even if you just get one of those free or $25 brake safety inspections to get it diagnosed.


Oh and I'm guessing the reason no one else has offered advice is because it is one of the most difficult to understand questions ever posted due to the poor wording and incorrect and contradictory terms used.

Hope you get it sorted.

Oh and one more thing, if that bolt you used to blank the rear line port while you were driving around on only front brakes was a bees dick too long you've more than likely phucked the master cylinder.

[StuRT104]

Cheers for that, yeh sorry about that post i dont know anything about brakes so its kind of hard to fully explain everything. Im gonna check the master cylinder because i checked the gasket on the inlet and everything seems to be ok. and btw the car wasnt on the road while it only had front brakes i was rallyin it around my property, im not that stupid.