HH56

If pedal went to floor, then most likely cause is compensator valve in MC. This is essentially a large piece of rubber that is held up in position by a spring. When brake relaxed, the valve is tipped away from port so fluid can replenish MC from reservoir, but when brake applied, spring is supposed to pull valve back straight to cover port and the pressure inside MC forces it to seal tight and pressure goes to wheels. If that valve didn't seal or cover port, then fluid in MC would go back into reservoir, not to wheels and pedal goes to floor. Maybe there is a speck of gasket or something floating and trapped in MC that kept it from sealing well or the spring might be weak. Depending on which cover, you have, removing the fill plug will give a view of the port and spring part of valve. With pedal relaxed, valve shaft will be at an angle, but with brakes applied should be straight up.

I can vouch for RO saying there was almost no brakes. Even if hydraulics perfect, with the treadlevac, you have no mechanical advantage as there is with manual brakes or other design power assist units TVac is a straight 1:1 and the entire power is devised from vacuum plus what little you put in. Other systems utilize mechanical advantage as well usually around 3 or 4 to 1 so if you are standing on TVac brakes with 150 psi foot pressure you get that to wheels wheras other designs might get 4-500 lbs with no vacuum. On a trip to Yosemite, in a 56 Pat that developed vapor lock and stalled, we started going backwards. The driver, a rather robust individual, literally stood on pedal and was pulling hard enough on steering wheel for extra leverage to bend it was barely able to bring it to a stop before we went off road. That was too much like excitement for my taste. I believe Packard Panther site has an article about Tvacs and his efforts to adapt modern units with a mech. advantage.

A sticky vacuum check valve is one possibility as is the hose inner liner collapsing from the vacuum especially if its an old one. Valve might break free as it heats, but hose would probably stay collapsed until engine stopped. If seal failed in past and there is any brake fluid in vacuum side of treadlevac, it might have stuck poppet valves which finally broke free.

A method I've used is to spray the area, then let dry just a bit. Have a small block of wood size and shape to span 2 or 3 letters and wrapped with a layer or two of cloth (something like a T shirt) and damp with laquer thinner. When the paint is just tacky carefully wipe the letters. The wood will ride the letters and paint on top will come off leaving the paint in depressed areas. It is tedious and be careful not to let the cloth get too wet or be so thick or loose it will compress down into depressed areas. Do it once or twice, using clean areas of cloth, then let paint dry some more and do again if needed to clean up any smudges. A bit of experimenting will let you judge the thicknes of cloth and technique.

Fred Mauck in Santa Ana has them as well as fuel pump & tune up kits too if needed.

I think new would be the way to go unless you could latch onto a complete working system and transplant that -- which would be a project and a half and frankly, not that great a system IMHO. It would be a challenge to make just the compressor work with other modern stuff even. I'm kinda in the same dilemma with my 56 and the Leheigh compressor which needs apparently non existant parts. Am seriously considering a new Sanden replacement but toying with the idea of some kind of fibreglass cover that would disguise it somewhat. Maybe thats a really stupid idea for reasons besides the ones I've already thought of but if I go that route, would like it to look somewhat original at first glance.

It does appear to be the correct 53-4. I hope the new owner will also have the brackets and idler pulley setup already because they will probably be just as expensive and harder to find intact.

Expensive! 750 for the pair last year. I did check with several others (including local talent) and some prices were lower, but I liked the answers to questions the serv mgr gave and the fact he actually knew a Packard with Rochesters wasn't built by GM.

Might also check out www.carbsonly.com in Burbank, CA. I had my 56 Rochesters done (with restoration- rebushing, replating etc) and recommend them also. Carbs look and run like new.

Just for grins measured my 56 this AM. When going thru level area it is pretty consistently 14-16 amps either direction, but when nearing either extreme it goes up to 22-24 amps. Packard changed the fuse to 30A in 56 but the rest of circuit, aside from the relocated components and slightly different switches on the control side, is pretty much identical to 55. If after checking the items everyone has suggested and finding things OK, if your fuse is still 20A maybe a change would help. The fact it worked until recently makes me think you will find something amiss though.

Anything on tech bulletin 55-T2 applicable (on PackardInfo site)? Also, any corrosion or poor connections between starter, fuse, solenoids (even internal in solenoid), and motor would cause an increased current draw and blown fuse as well. On my car the most work seems to be in the up direction the last few inches, so possibly yours is just about maximum and the little extra required in the last quadrant is enough to blow the fuse.

I can send a few pages from a Motors Manual re testing and operation of the different brand instruments and what symptoms are for various faults--also a service counselor (Vol 22-3) for 48 with a procedure if it's not on PackardInfo site. The question is what type/make you actually have. I just looked at my 47 Custom (currently apart) and surprise-surprise found it has a clearly labeled Stewart Warner resistance type whereas another 47 I did a few years ago had bimetal. Don't even remember reading that Packard had used S-W instruments. I always thought the different part numbers between jr & sr cars & various models was due to tank capacity & gauge color but am not sure now they weren't still facing shortages and used what was available or maybe different instruments for different models like the Delco-Autolite stuff. At any rate, the test procedure would have to be determined by the type and they all suggest use of a spare tank unit. Since the Packard procedure for temp test uses a gas sender, don't see any reason a temp sender and boiling water couldn't be used for gas--just don't know which way it would read hot vs cold-but there should be some change.

I believe a change might have been made on the 24th series from the King-Seely bimetal type (as 49Packard mentioned and also used on 47) to the AC or Autolite type with resistance units. The service training book for the 51 models describe a "new style temp sender with compressing resistance discs" so gas amd oil would have gone along for the ride. BigKevs numbers sound about right from what I remember. I have had several apart and 3 things stand out for examination. The rivet area where the flexible brass strap to contact arm and the bottom end of the resistance unit attaches to can, the entire gauge assy and where it attaches to the round plate mount to tank. These areas can both corrode-the rivet to can or strip and between the plate and can. Any extra resistance in either place will cause faulty/no reading. On one unit the brass strip inside was broken. So far the contact and resistance wire have been OK.

If all else fails in finding an original, this gentleman might be a possibility. He manufactures an aluminum setup and advertises in various Stude & Packard publications-not cheap though. Jack Nordstrom, 4975 IH-35 South, New Braunfels TX 78132, phone 800- 775-7077.