21 replies to this topic

[adam]

Hey all,

I've just installed a set of supra brakes on my jzx100 and having bled the system, motor off, undo furthest caliper from master, pump brakes, close valve while pedal is held in.. Etc etc..

I'm having issues with spongy soft pedal feel. There are no leaks. Pedal is very soft to begin with (motor off) but after a few pumps it gets heavy.. As it should. But as soon as the motor has started and do the same process, it just goes right to the floor.

I think it's obvious there's still air in the system but my question is, before I do another bleed, do I have to do anything with the abs module? Will the air trapped in there be released with another bleed ? Or will it now only come out the next time the abs is activated?

Any help is appreciated..

[whiterolla]

Would love to know Adam, been chasing this for ages, even before my brand new supra's went on, have replaced done:

new supra 4pot FR
new rda slotted discs
new jzx100 braided lines
new pads all way around
Bleed the shit out of everything
2nd master and brake booster out of wreck which had mint feeling brakes

I am at the point I think I will pay a pro to look at it.

[Dropbear]

First of all you need to determine where the pedal loss occurs be it the master cylinder or at the wheels.

Preferably you'll need your car up on a hoist or at very least up on stands to allow easy access

Clamp off the flexible lines going to the wheels (if you have braided hoses forget it)

With all wheels isolated check the pedal feel, if it's rock solid the problem lies in the wheels,

If it's shite then more than likely you have a master cylinder issue be it air trapped in the cylinder or damaged cups.

If pedal is good hold light pressure on the pedal and release the hoses one at a time without lifting pressure off

(pedal should drop a little each time) if pedal turns to shit on one wheel then that's where you problem lies.

Now also if you have just installed brand new/reconditioned calipers, pads & rotors they will need to settle in and pedal will improve with time.

And if you just bunged on some 2nd rotors and new pads or vice versa you deserve to have problems,

ALWAYS machine/replace rotors when replacing pads, and replace pads when replacing rotors.

Once you have determined the source of your problem then you can go about rectifying it, this simple check should only take about 5 mins to

do and will save a lot of time and heartache.

[5hu7o]

nice write up!

[Trav555]

http://www.aa1car.co...bs_bleeding.htm

Depending on what the chaser uses might be a job for a toyota mechanic with a service book haha

Look over the abs cylinder for a bleed nipple, also maybe try the repair manual though i think its in russian

Cheers

Travis

[Trav555]

Ok just had a look at The mk4 supra abs and brake repair book

http://www.mediafire...cjyhmm5rfat78n4

Hope it helps mate

Travis

[adam]

That sucks to hear Simo, I've heard about you suffering this issue also but thought you managed to fix it before the last track day.

Awesome reply, Dropbear, cheers. Will definitely give that a go next time.

And thanks Trav, I'll take a look at them after all this christmas stuff is over.

I got around to bleeding the brakes again and yeah, definitely no luck. Will definitely have to try that clamping off each line method.

I think there's air in the stupid abs unit though.. So frustrating.

[Trav555]

I think the trc and abs unit are the same thing in that pdf I posted up so bleed both

Good luck mate and let us know

Cheers

Travis

[whiterolla]

Definitely wasn't sorted before last track day, haha had a go anyways, nice write up dropbear, pretty much where I was at with it was clamping the lines. although I has braided ones :/ but next step was to bleed the master cylinder properly, tried the fingers over the lines method as per toyota guide but no resolve, have some old lines that I will attach and run back into the master and see if perhaps thats the problem.

[Dropbear]

Air in the master cyl can be an issue if you don't bench bleed it properly due to the angle it sits at in the car,

Few ways you can rectify it.

Pull it back off and bench bleed

Park the can on a steep incline to get M/cyl horizontal and bleed, crack both pipes from cyl ,depress pedal ,nip up pipes and release pedal repeat until no more air comes out

Here's mine slid down the hill with brakes locked and came to rest at the bottom  pictureview.jpg   26.96K   13 downloads.

Or you can unbolt M/cyl and rotate until it's beyond horizontal opposite to how it is in the car and lightly jiggle the piston in and out, this will bleed the air back into

the reservoir through the compensation ports.

You may need to use all three to achieve desired result.