Thanks Mal, I have to be a bit careful here as I am about to sell the Daimler and you may be accused of "RAISING THE SHARE VALUE, ETC,. Please be advised that ALL Packard owners are invited to have their radiators cleared out if :

1. they can help with the task

2. They can put up with the bad language if I can't get the right size hose clips

3. If they are not involved in my losing keys that are not actually lost.

It was great to see the car in Canberra, Mal and Lindsay allowed me to drive it and no matter how many times I tried to fry the clutch and keep the engine in the red line ( sort of valve bounce if no tacho) , they kept their cool. I could hear someone reloading a firearm in the back but they were great! Mal offered to take one of my cars to Bonneville (not sure what for?) He says that next time I come to Sydney he will fix me up real good.
Thanks Mal and Lindsay. P.S. Our Swap Meet was down about 50 % in vendors ( 250 vendors), but we had approximately the same number of punters through the gates (1600)

Thanks for the visit and we should keep in touch. Peter Toet

G'day Eric, Is this a conversion for 12V only or is it able to be adapted for 6V systems. Best regards Peter Toet

Well, Gentlemen, you have certainly convinced me that the Treadle-Vac has a potentially serious problem, far worse than any conventional single master cylinder problem such as on all of the non Treadle Vac Packards. There are undoubtably a large number of Packards on the road with Treadle ? Vacs or single cylinder master units.
Do we have a ?duty of care? to warn them?
I think not, because
1. Each Packard is equipped with an emergency cable brake on the rear brake shoes, the system should be in good operating condition.
2. Each Packard has a manual or auto gearbox in which a lower gear may be selected to assist in retardation.
3. Each Packard is equipped with an ignition switch which cuts the engine ignition.

I have had a number of complete brake failures, the most notable was in 1967 on the Sydney Harbour Bridge, in a 1939 Chev Master Deluxe, when I broke an axle which moved out and rendered me brakeless, gearless and speechless. The incident wrecked a good car and a potentially good relationship with my then girlfriend.
Notwithstanding that service records do not exist for over 50 year old vehicles, bad news travels via Service Bulletins, Jungle Telegraph and the Mechanic's grape vine. I have heard many stories about car's weaknesses but I have heard none about the treadle ?vac. I hope that mine continues to give good service in the 56. I am about to fit a remote power booster ( non treadle ?vac) to my 1938 Packard 120 and that may be another thread. Best regards and it has been a very interesting item, once again I am sorry that I unfairly involved Silicone brake fluid. Peter Toet

"Cutting to the chase", has anyone documented a case where the compensator port spring has actually failed in operation? I would doubt it as the spring is a very relaxed spiral, and does not compress in operation, simply holds a few pounds closing pressure tilting the seal underneath the port. My vocation takes me to a number of vehicle accident repairers, jam-packed with damaged current 2007 model BMW's, Mercedes, Saab and other vehicles with "fail-safe" braking systems. I would rate the "loose nut at the wheel" ahead of any perceived problem with the treadle-vac system on my 56. I am not sure but I understand that the spring is not included in the Bendix repair kit for the treadle vac. I would certainly check any springs such as these out for corrosion or damage during overhaul but where do you draw the line in overhauling and driving 50 to 100 year old vehicles? I recently had the steering head of my 1907 Triumph 500cc motor bike break off completely at 25 mph whilst negotiating a bridge crossing. I am sure that it never happened before and I have replaced the item and am confident of another 100 years on the bike ( I wish!) Risk Management is the key to survival in any vehicle, old or new. Peter Toet

Hi Turbopackman, I feel that I may be inserting my head into a hole in the fence not knowing what is on the other side, and I may get it kicked but, what is so unsafe about the treadle-vac? Peter Toet

The NOS compensator valve was amongst a box full of NOS brake parts which I inherited wth the 56. The parts were NOS from one of the two Australian Packard Dealers in 1956. IRA BERKS in Sydney. It was not in it's original packaging but had no seating marks on the seal to indicate that it was used. The break was clean and I can only assume that it had been stressed during storage or was faulty from new. I doubt that it would be a common fault and I was amazed to see the part broken. The interesting thing about the pressurising of the brake system is that towards the end you could sit in the car after driving and watch the light come on after 5 minutes, without touching the brake, indicating the role that the compensating valve has in allowing the expanded system fluid to escape from the master cylinder to the reservoir. I am going to recondition one of my spare Treadle -vac units with some of the same NOS spares and be a bit more observant this time. Peter Toet

Hi BH and Packard V8, Hopefully the end of the story. I pulled the Treadle-Vac out and on inspection, found that the bottom tip of the Compensator valve (below the seal) had broken off completely. Hence no cylinder to reservoir transfer and no temperature compensation, etc and a good reason for system build-up. I find it most interesting that it took so many applications of the pedal to induce the symptoms of system pressurisation. I now have way too much pedal travel and fear that the rear linings are "toast". They certainly smoked as much as 5 minute toast anyway. I am pleased to advise that I am going to revert the system back to Dot 5 Silicone as soon as I have checked on the linings etc, and that I am sorry to have blamed Silicone in the first place. Best regards and thanks for the responses. Peter Toet

thanks for the tip on the vent and the hose, I shall check them on stripdown..

Sorry, I was not clear in that I only have to bleed any one of the four wheel cylinders to relieve the pressure. I inserted a tell-tale light under the dash which glows whenever I pressurise the brake system. It normally goes out immediately I release the brake pedal, but lately it has remained on after about 5-10 applications, this is accompanied by a loss of pedal travel as the system does not release. The brakes do not release themselves within a half-hour (the longest that I have left the pressurised situation). It also makes no difference if the vacuum system is operating or not. I am very interested to find out the cause. I have lots of spares so I shall start the replacement program as soon as I get some time.

Ahem! Well it has developed into a case that the system blocks up with pressure after about 5 - 10 brake appliations, then you have to hydraulically release one of the wheel cylinders. It came to a head (literally) when we were returning on a 200 mile trip, towing about 750kg of motorbikes. Because it occurs at all wheel cylinders I have determined that it is in the Boost Cylinder. I shall remove it and replace the residual check valve with a NOS item and advise if it cures the problem. I shall also comment on any swelling of the parts as I still do not blame silicone brake fluids at this stage. I agree with previous comments that it is unlikely to be the compensating port. best regards Peter toet