Brake Pedal Feel...spongy

[Koffee-Black]

Hey guys, i know Supra brakes feel a bit "mushier" than others, but my car hasnt been right since day one.
Symptoms:
No feel untill half way
Pump brakes while car is on, and it does not get hard
Pump brakes while car is off, and it does hard. but not that hard.
Almost no bite whatsoever.

Pads, not sure, whatever was in there, but have ordered some Hawk.
Check Master cylinder, and it looks all dry in that area.
Have bled brakes, even from the Master Cylinder. Looked like it had never been bled before. The Fluid was black as, and even had some skin!!

So any suggestions lads??

[blacktop]

Brake booster might have a leak

[rob]

looking at the master cylinder will not tell much

the seals in the master cylinder are most likely fucked from gunk in the fluid. So when u press on the brake the fluid rather than being pushed into the brake circuit, gets past the seal in back into the reservior.

a full fluid flush and master cylinder rebuild would be my first step, especially as u say it looked like the fluid has never been flushed.

[jimmmayyy]

agreed. flush fluid first and then see where you stand. if it is still spongy after, then new cyl seals and check booster for leaks.

[Koffee-Black]

thansk guys, so if i do a full flush again, and it happens, how the hell do i rebuild the MC?

Could my calipers need rebuilding?

[DRIFTAMK3]

they preety much hone the sleeve that the piston goes in dependin on wear replace the piston in the cylinder as well as new seals and grommets

also are you sure its not just crappy old fluid...

brake fluid tends to gather moisture over time which thins the fluid that would explain a spongy feeling as well as air in the line etc.

thats why you should bleed and change fluid at least once or twice a year

[wa5]

80 series Supra? Your car has ABS?..... Be very careful bleeding the brakes, IE doing a full fluid change, I dont think getting air in the ABS unit would be a good thing.

[amichie]

Make sure you bleed the rears also. Air in the rears will make it feel spongy also.

[Koffee-Black]

yeah it has ABS, and yeah A80 Supra

[wa5]

Perhaps there is someone here with some experience of bleeding ABS equipped brakes.... Any tips?

[1jz68u]

My brakes faded the other night slowing down from a decent speed, the strange thing is i have slotted rotors and greenstuff pads. took it to someone today and the think that the fluid could be the problem.

he said he has seen heaps of imports that have never had the fluid changed and he said it always causes dramas.

also asked him about bleeding brakes with ABS he said you sometimes need to bleed the abs unit as well.

my 2cents

[oldcorollas]

brake fluid MUST be changed every 1 or 2 years at the japanese Shaken inspections...
imports should have had their fluid changed at the previous shaken.. but that could be a few years ago if they have been sitting in a yard or on docks.
when mine was changed at last shaken, it made good brakes feel much better,, and that fluid was only a year old (as i rebuilt calipers a year before)

definitely flush out the whole system.... fluash once at all points, drive for a while, then maybe flush again once dislodged crap comes out.

maybe it has had incompatible brake fluids mixed??? ie 5 and 5.1 or whatever?
go back to the toyota recommended 3 or 4 to start...
and as mentioned above and elsewhere on forum, ABS can be a bitch to get air out of....

[GUN METAL]

Yep give it a good flush first.

if it not leaking anywhere there could be a soft spot in one of the flexible brake lines, get someone to load up the brakes and check for balooning brake lines.

I assume the pedal is not dropping all the way to the floor right ?