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Yep. That is the second time it happened in 18mths. Really weird fault and I do need some help on finding a cause here.

Let me lay out the scenario:

Only happened twice in the 1982 wagons long life. The first was last year sometime and I had just driven a long haul to Sydney on the expressway towing a trailer. Coming off the exit at beverley hills NO BRAKES, nothing, foot straight to the floor. I heaved on the hand brake and all the occupants gave a sigh of relief.

I crept into the nearest side street and we cooled our heels. I bled the brakes a bit (no air noticeable), still soft, then over an hour the brakes come back to life. Not trusting them I limped on using the back streets and the handbrake just in case.

I did a full strip and clean of the forward system including the mastercylinder where i put a new kit in it was in good nick except for some grit in the end of the main cylinder). I thought the grit might have got stuck under a cup and prevented seasling ? New fluid and it worked OK fror a year or more.

Then last week it happened again, in Sydney after using the M4 for 20 km, with a trailer (unloaded). Came off the exit ramp and volia - NO BRAKES !

Stopped the car, bled the master cylinder of some fluid to see if air was in there, none at all. Pumped the brakes a lot and eventually life came back and it has worked ever since, though I just do not have the confidence in the system that I should. So it is sitting idle in the yard until I can figure it out.

The only symptom I can add is there was a faint smell of brake fluid when the vehicle was started. It happens occasionally without any obvious fluid around the vehicle (have looked several times). It did happen on the morning of the last NO BRAKES incident.

when did you replace the MC last? what grade brake fluid are you using? is there a brake dragging?

when pedal goes straight to the floor it usually means theres a leak somewhere...eg Brake Hose Broken.

but if it comes good again i cant think of nething.

have u checked out ur wheel cylinders or Drums lately.

Sounds like Master Cylinder is on way out.. time for Liberty Master Cylinder upgrade
Cheers
AP

Yeah if you can smell it then theres bound to be a leak somewhere. Maybe only when that part gets really hot though (like on a long trip on the expressway with one caliper or cylinder partially locked on perhaps).

It might be worth considering taking it into a brake place, brakes are one thing you don't want to take too many chances with - you've had two near misses already!

AndrewT wrote:
It might be worth considering taking it into a brake place, brakes are one thing you don't want to take too many chances with - you've had two near misses already!

I'm on his side - best take to brake place - if it fails you can go back and tell em off or sue them, if it was you doing the brakes and it fails and hurts someone which is your fault for "playing" with the brakes - will have to put that in your heart for rest of your life...
Happened to me once with the Commodore and I played around with the brakes (upgraded from V6 to V8 brakes which the calipers failed) and run thru red light with near misses... that what i realised about...
Cheers
AP

Its a great way of testing out the clamping force of your ring isn't it - real pucker factor stuff.

It happened to me in Ireland - in a brand new 2001 (1500 miles) Fiat Ducaro 6 berth campervan - coming down a hill to a roundabout. I had the entire family (5 of us) on board - and the brake pedal went to the floor at 100kph. Handbrake full on and down through the gears - revved its tits off. It turned out that the engine hit the pipe out of the master cylinder and broke it off - so no hydraulics whatsoever. No dual circuit. There won't ever be another Fix It Again Tony (FIAT) in my life.

If you are smelling brake fluid - its leaking. I'd be looking in the booster then each potential leak point - or, as has been said - take it to someone. If you want some practice first - I've got a Jensen Interceptor here that has a siezed caliper by the look of it. ..........

If you want to locate the fault try clamping off the hoses to the calipers(gently so as not to crush them,there are plastic pliers for this purpose)and the same at the rear and if the problem is still there then it is either in the Master Cyl or the pipes(what about the hill holder?) and if it is fixed then the problem lays in the caliper,pads or wheel cyls. Maybe check the wheel bearings too because if the wheels are wobbling too much it can cause the rotors to push the pads back in? Dont drive it but with the hoses clamped or maybe not drive it at all.

Same thing happened to me about 4 days ago coming down a steep near Mt Coatha. I replaced my rear drums to discs about 3 months ago. When I did the replacement I failed to check the 2 bolts that hold the pads in. (just dumped the whole assembly on, no need to touch the pads) well those 2 bolts had fallen out and the pads went walkabout. going down the hill foot on pedal .. too the floor my foot went .. fortunately handbrake saved the day ..


250 dollars later after tow and new parts soob is back on the road .

One thing to check, if the diaphram in the brake booster gets a small enough hole in it, the brakes still work, untill enough fluid gets on the wrong side of the diaphram...

Daza.

Thanks all for the ideas and advice !

It sure has me stumped. I will try the clamping the hoses (like that test method with the plastic clamps).

The brake MC was done just after it happened last year, checked out carefully, cleaned and all new rubbers. All fluid flushed and replaced with new non synthetic. It does not consume brake fluid at all, have not had to top it up in the year and it had not dropped level at all ?

I have a 1984 model in the back yard, I might look at swapping the brake components from it (has different disk rotors).

Ciao

So, will a liberty master cylinder bolt straight in to an 1982 model ? How about an L series ? Do you need the vacumn drum as well ?

Yes it will go straight on... as long as u get the one that has the outlets at the bottom. You may need to go to a hydrolic joint to get some fittings to block off the other 2 ports found on the side of the lib master cylinders though.

My personal opinion would be to buy another MY wagon for a few hundred dollars and swap all the brake parts except the metal brake lines. This fault would scare the hell out of me... ya NEED to trust your brakes.

Forgot to add... lib brake booster will also fit but ya need to use the brake pedal bracket off the MY booster and make sure u use the metal spacer that is on the MY booster too. You may need to slightly kiss the side of the engine bay wiht a hammer to get it in.


Dave

Just throwing something else out there as a possibility (it has happened to me): buggered front hub / hubs. The play spread the front brakes away from the discs and can cause intermittent apparent brake failure or at the least a need for pumping the pedal.