Hi all, It took 5 removal/replaces on my 56 Patrician (yes with the PB auto) to sort out that the main problem was around 0.010 wear on the input shaft where the rear pump pressure goes in. The Packard Ultramatic is a very good box when it is working properly. The unfortunate thing is that most automatic gearbox repairers have no knowledge of converters which "lock-up" or of rear pumps shutting down front pumps.
The problem with any of the modern transmissions and a Packard transmission that does not change over to the rear pump and engage the converter contemporaneously (at the same time) is that the converter overheats and cooks the gearbox. The modern gearboxes get over it with very low stall and lightweight cars. With a Packard Ultra or twin-Ultra you had excellent engine braking and it runs very cool, even towing very heavy trailers. I have had a Torqueflite V8 trans ready to install since 1978, but I cannot convince myself that it is an improvement.
I have tried to second guess Packard engineering on a few occasions without success so I guess that I am either truly brainwashed or a genuine Packard Nut. Peter Toet
P.S. Get the Ultramatic box repaired/ overhauled

Hi Brian and Keith, I'm pleased to see some good info flowing and it is all appreciated. I concur that the most likely culprit was excessive swelling of either the master cylinder primary cup or a faulty residual check valve. All that I know is that the "failure to release pressure" situation has not re-occurred since I conducted a crude blow -out and replacement of the dot 5 with a dot 4 "guaranteed no seal swell" brake fluid. I did replace the primary cup, residual check valve and compensator valve with NOS items when I put the replacement booster in. The NOS items were however 50 years old so they may have been very shelf life affected.
The 56 overhaul manual Section on Brakes has the heading ESAMATIC POWER BRAKES, so I guess the Bendix family name was TREADLE-VAC.
I am hoping that all goes well with my brake system and thanks for your input, which has increased my understanding of the system. Best regards Peter Toet

Hi Packard V8, I suddenly remembered that the seal swell problem related to the main piston seal and the seal swell meant that it did not come back as far, which affected it's ability to tip the compensator valve seal. it did not relate to seal swell on the compensator seal at all. best regards Peter Toet

Hi Packard V8, I just spent 30 minutes drafting a great reply to you about your last three replies then lost the lot when I ran out of your threads, then lost it all. Oh the joy of computers!
Bikes? I am not sure about what green eggs are but I guess that they are Army bikes. I have a 1917 Excelsior Model (1000cc) ex US army, a 1927 Harley J ex army (1000cc), a 1939 Harley WLJ 1200cc, ex Japanese army (repatriated from Sumatra in 1985), a 1941 Indian 741B outfit ex Australian Army . The closest thing to your 48 Chief is my 1928 matchless X3 (1000cc) in which I am running 44 Chief rods, rollers and a hand made crank pin.
You are so right in that the compensator valve appears to be a very crude tipping device and I was very surprised that I achieved the lock-up problem. The trouble-shooting suggested seal swell so i changed the fluid and it has worked since. I am a great believer in "if it aint broke - don't fix it" I did replace the compensator valve with a NOS part when I put the reconditioned vacuum unit in.
You are most probably correct that it it is a Treadle Vac unit and I am not fully up to scratch on the fitments of a 56 You are also correct in that the compensator seal simply sits against a face, but once you have pressure in the master cylinder doesn't the pressure force a pressure seal on the Compensator valve until the master cylinder piston tips the compensator valve rod, to release the pressure? What do you think? Best regards Peter Toet

The only parts which I replaced were in the booster, I flushed out the rest of the system with compressed air, Methelated spirits and compressed air again. I have used this method on quite a few cars (and bikes) without problems, until the Patrician and a late Eighties Nissan. Some vehicles appear to cope with the nominal seal swell (approx 7%)of the SBF, while others cannot.

Hi all, Two posts in the one day, I must be hooked! Please be cautious in changing to silicone brake fluid (SBF)in the Esamatic brake system. I USED to convert all of my hydraulic brake cars to SBF, almost entirely because it was lubricatng to the seals and did not attract/absorb water. (currently have 4 packards on SBF)
I recently had an experience whereby about 6 months after I converted my 56 Patrician to SBF, the brakes started to not release, to the extent that on at least 3 occasions they locked the brakes up completely. My diagnosis was swelling of the main seal covering the compensator port, not allowing fluid to release back to the master cylinder reservoir. It would appear that the nominal 7% seal swell due to the SBF was sufficient to block the system, (and it is one of the most probables in the factory diagnosis). I quickly pumped and relaced the SBF with one of the low hygroscopic DOT 4 fluids and have not had any problems since. I have installed a monitoring light under the dash which indicates when there is pressure in the brake system and so long as it goes off quickly I am happy that the 7% seal swell may not be permanent and shall hopefully have no further system lock-ups. Happy Packarding Peter Toet

Just 2 cents worth and agreeing with Owen Dyneto, the hood of my 54 Caribbean is steel /lead and much heavier than my 53 Clipper steel hood. I would suggest that the brace is an absolute necessity given the lever effect of the modified heavy outer hood (scoop) end, and the marginal upward push of the standard hood springing. Peter Toet

Hi all and thanks for the interest. Araldite is a trade name and is a two pack adhesive with probably at least a dozen equivalents in the US ( J.B Were's liquid metal?) I was very impressed with the quality of the original switch internals with no oxodising or burning after 50 years, and doubt that a modern switch would be any better, apart from the unknown problems of having to adjust one switch to another application.
Before I affected the repair I looked at, and purchased some alternative switches and they all relate "generally" to reversing switches and are useless as they "generally" operate in reverse to our limit switches with less current rating.
I decided to fit the snap connectors because the original wires are long and the unbroken one would be difficult to control in the lathe as you spin off the swage. The whole operation was extremely simple and it is akin to your first swim ,in that you are confident, yet scared to attempt it, but exhiliarated when you succeed. Good luck and don't throw any of the old ones out. Best Regards from Down Under Peter Toet

Hi all , I have a 56 Patrician and recently it sat down at the rear and would not come back to normal height. I switched off the system, put the vehicle on a hoist and discovered that the UP limit switch was open circuited. Immediately adjacent to the up switch (beside the tailshaft) the plastic was ok but it felt a bit soft and sure enought the copper underneath was broken. I checked out the availability of NOS switches and they are about $175 which is OK except that they are also 50 plus YO. I decided to repair and cut the remaining wire about 4 inch from the switch. I put the switch in a lathe and spun the swage off the end to allow the switch to come out. What a well made and solid switch! I soldered new wires onto the contacts, roughed up the interior of the casing with 180 grit, mixed up some 5 minute Araldite which I coated the switch block internals with. Pulled the new wires and block into the housing and left it for 24 hours to set. I fitted snap connecters to the wires and did not have to disconnect anything from the torsion switch box. It works extremely well and I would do it again anyday. i hope that this has been of some help Peter Toet

Hi all, It may appear to be a bit strange to reply to my own thread but, I felt that i should qualify my thread by stating that i have NOT tried to fit the Falcon discs yet. I was probably the first in Australia to fit a 35-38 gearbox top onto an R6 overdrive and make the system work, but that's a different topic. In reading the Brake responses it is pretty obvious that many people have tried and that I may encounter a big problem straight up. I would like to see a disc brake option for the Packards. Good luck guys. Peter Toet.