need help with spongy brakes 80 series

Sounds liike an air lock in front brakes. Try having someone push pedal down then open brake bleeder then closeit & repeate & see if any air bubles come out. Some systems are prone to air locks.

Hi. Flexible hose/s swelling under pressure. Caliper/s speading under pressure. Maybe try clamping each side flexible hose one at a time. Did the problem occur quickly or over time? Maybe try to think back as to things that were done to cause the problem. Other than that I would be curious to know what has happened when you finally work it out. Bob.

Hi this is a common problem. have seen it on other forums.http://www.lcool.org/technical/technical.html replace the front flexable brake lines with braided hoses .http://www.braidedhoses.com.au/wherebuy.html

I will need to do mine very soon i have that sinking feeling,around $200 for two hoses.
But they say it improves the brakes %100.
Rob.

What about a leaking brake booster perhaps????

Hi i would agree with the hoses expanding had the same thing happen to an old holden years ago, they don't need to expand much for the pedal to start to go down.

Hi peejay,

I am with Toyocrusa, Rob & Pat - replace those hoses. I was not really a believer a while back as I could not 'see' the hoses swelling and thought that it could not be the problem. Changed the hoses and problem disappeared.

Another possibility is that there is air in the lines but it is trapped behind the pistons in the wheel cylinders. Normal bleeding only clears the line down to the bleed nipple and not all the way to the piston. To effectively bleed the brakes you need to push the pistons right back with something like a 'gee' clamp.

KK

A mate of mine had a similar problem with a GQ.
After days of bleeding in every way including pressure bleeding
he noticed someone before him had put a left hand side calliper on the right side. That worked fine except the bleeder is at the bottom. He took it off , turned it upside down, gravity bled it then put it back on and has had no problems since

peejay

My cruiser is 80 series 97 model, had the pads replaced all round and the hand brake adjusted.

When i got vehicle back same prob as you, went back to repairer who i knew, he said no worry just come back in a week and we will see how they are then,(yea right thanks),

As i was leaving next morning for caravanning trip had to cancel that idea and took vehicle to the biggest and the best and the most reputable clutch and brake repairer in my area.

They test drove vehicle and advised me to leave vehicle with them a not to attempt to drive it home.

They had the cruiser for a week, they tried everything, overhauled master cylinder, booster you name they did it, some of their men are veterans with 30 yrs experience, they could not work out what was wrong.

After one week of tearing there hair out they very apologetically returned the vehicle to me, said it had them stumped, they only charged me there actual costs for the booster and master cylinder.

I continued to drive the vehicle around, as despite the brakes slowly sinking to the floor as you describe, they still provided braking when required and i felt it was still safe to do so.

They came good on their own and they are working fine, still no idea ?????
of what the problem was or how it resolved itself.

Geoff43