aw11 brake pedal goes to the floor sometimes

[KLR16V]

i have an aw11 mr2 and since i have had it, occasionally while driving the brake pedal will go straight to the floor and the car will only slightly brake. then if i pump the brakes once it fine, stops perfectly.

this problem only happens once about every 5-10 mins of driving

i checked my brake fluid and that seems ok.

does this mean i have air in the lines somewhere?

how can this be fixed?

cheer, Daniel

[monkeymajik]

Most probably.


Bleed your brakes and see how it goes.

[30psi 4agte]

sounds like air you will need to bleed the brakes starting furthest from the brake master.

push down on brake pedal while someone cracks open the nipple on the brake caliper. then close the nipple and lift foot off pedal. repeat process on all calipers till all air is out.

May pay to check all brake components for leaks! esp brake lines

[Bananaman]

One man bleeding kits are well worth the $10 or so, beats getting the gf/wife/mum to assist in pumping the pedal, thats for sure. Seems to work better too.

[mullett]

Man, that IS NOT good. Firstly, bleed the brakes, if you're unsure how to do it, or don't have a mate and a couple of axle stands, get someone else to do it. If it still happens, rebuild your callipers and master cylinder.

RM.

[EldarO]

dont they have a vacuum assist? maybe the line is loose/ leaking...?

Eldar.O.

[ra23celica]

If not air in the system, which 90% sounds like it is, then fluid is leaking past the seal inside the MC, which should be honed and rebuilt with a new seal kit.

[feral4mr2]

indeed, given the age of these cars you will probably find the master cylinder has pitts on the bottom of the bore from moisture in the brake fluid (we all leave it in too mong between flushing it)...
i sent my master cylinder away to get a stainless sleeve put in it and then i used a hiace seal kit to re-kit it. works great now.

[KLR16V]

thanks for your help guys, il probably go and buy one of those bleed kits today or tomorrow and give that a go. il let u know what happens

thanks again,
daniel

[mullett]

If you can find one, get a vaccuum bleeding kit. They are teh leet

RM.

[oldcorollas]

the rubber seal on the plungers can also break internally, allowing you to sometimes brake and sometimes not...

not braking is a serious problem
if if does it at all after bleeding, then pull apart master and then calipers. no point taking a chance with your life and a good time to do an overhaul

upgrade?

[Arch]

whats a one man bleeding kit?

[30psi 4agte]

its a one way valve that you put on the bleed nipple so that when you lift up on the pedal you dont suck in air.

[feral4mr2]

whats a one man bleeding kit?

a peice of plastic pipe stuck into the top of an empty 700ml plastic coke bottle that 1/2 full of fluid and some fencing wire to tie it higher than the bleed nipple...

[KLR16V]

i went out and bought the kit today and i have bled all the brakes.

i took it out for a drive and the brakes still occasionally feel spongy,like once every few minutes it will feel really soft then if i pump it it goes back to normal... but at least the pedal doesnt completly go straight to the floor.

i have noticed it doesnt really seem to happen while driving fast, it mainly happens when im waiting at trafic lights and slowly moving.

btw, when i bled the brakes i didnt notice any air bubbles coming out of the nipple into the tube. there was only old brake fluid so i kept pumping the brake till the new brake fluid came out.

should i bleed the mater cylinder too???