Brake pedal biting point

[DBoy]

I have just got my 87' Aw11 back from having its road worthy done, and one of the things they had to do was flush the brake fluid and replace the switch for the brake lights.

After they have done this the brakes don't start to bite until the pedal almost hits the floor. It brakes fine when it does get there and there isn't really any resistance till it does bite. So i wouldn't really say it was soft, it just has way too much travel. Is it air in the brake lines? i tried pumping the pedal fast and it doesn't start to bite any higher, which i thought would happen if there was air in the system. Is there some sort of adjustment for the biting point?

I checked the aw11 bgb and i could only see adjustments for break pedal hight. I am gonna call up the mechanic tomorrow when i get a chance but i wanted to ask some people who know stuff about Toyota's.

[jezza323]

brake pedal height is the adjustment you want

[naten]

i have the same thing in my ma61

brakes are good but the feeling is it doesnt start to bite very low in the travel of the pedal

my other car (nissan bluebird) is the exact oppisite, its really touchy from the top of the pedal.

maybe its just design? but id be interested to find out if it isnt

as for adjustment the pedal height adjustment wont fix this, you can adjust the throw between the brake booster and master cylinder but mine was already adjusted out so i dont know if this would cause it either.

[DBoy]

are u sure that i want brake pedal hight? because its not the hight of the pedal when its resting that i have a problem with. its when the brakes kick in when i depress the pedal.

Oh and i know theres a certain amount that i can be expected to put up with, but this is really bad, theres only about 1cm between the carpet and the pedal when its depressed fully.

[2jzhilux]

air in the system
get the brakes rebled

[MR22ZZ]

or they used a lower grade hydraulic fluid to what was in there

[lexsmaz]

Did they change any brake pads ? if they did, the pads may have to bed in first, could have a lip on the discs .. Sounds like the pedal is lower than it was before ? If it has air in the system the pedal will be soft ...
Wrong grade brake fluid wont be an issue unless you have cooked the fluid, & induced air into the system

[2jzhilux]

possibly master cylinder seals bypassing

[lexsmaz]

possibly master cylinder seals bypassing

I agree, except that he said the brakes stop well, when applied ...

[2jzhilux]

even if its bypassing there will be a little bit of pedal at the end and it will be hard, but youre right it wont stop well
must have missed that bit

[allencr]

It brakes fine when it does get there and there isn't really any resistance till it does bite.

Theoretically it should be solid as stepping on a rock, after the pads make contact, but since everything flexes, pedal, firewall, booster, hoses & calipers - that's hard to get.
If it doesn't feel spongy, then it isn't compressing air, and it wouldn't matter if it was filled with urine because no fluid is going to compress, so that rules out the MC, type of fluid and any benefit from bleeding it.
All you've got is freeplay somewhere - Pedal to booster, booster to MC, piston to pad and pad to disk, with the only thing having any real adjustablility being the booster to MC's pushrod. That pushrod shouldn't have been touched unless the MC was replaced, and even then it shouldn't be out by that much.

I think the pads were re-arranged and have some taper & grooves that make it need a little distance to make decent contact.

[jezza323]

pedal height is not just the pedal at rest, it also affects the pickup point, same as adjusting a clutch pedal height.

[DBoy]

ok well i changed the pads and front rotors myself before the road worthy. before i did this the pedal went down a fair bit before i would bite, but after i replaced them it was solid as a rock. Then i took it to the mechanic and hes done something to it. I am gonna call him now and see what he says. I'll look into adjusting the pedal hight on the weekend and see what differnece it makes.

[lexsmaz]

Check the pedal pushrod clearance if you need to, but the mechanic would not have touched it, & you have to make sure if you adjust the pushrod length you leave a bit of clearance otherwise you could be making the brakes drag ( ie stay on ) ...

[DBoy]

well i got it back and he adjusted something slightly. not sure what as my mum had to take the car down there. She says its not much different and the mechanic said he thinks the brake booster may be on the way out. so I'll check out the push rod adjustment on the weekend and if that doesn't work then i have to replace something.