Packard Forum Index » V-8 (1955-56)

Howard I agree with everything you said except 1. The easy to return to stock... I have no problem with over restoring and
if I had won powerball to pay for it or still physically doing things myself I would have no problem mounting a conceiled unit under dash totally hidden and 100% vetted and safe behind there and eliminating the old altogether. Why a need to go back to stock if stock is substandard and unsafe? But I understand the mentality. I did skim thru some other threads. Beating a dead horse here? If ac cars are not addressed then I guess a real solution is not finalized and I am not sure the other retros have been "out of sight or subtle" enough. I believe a HD unit with a sm master and relocated pedal bracket may be a solution to keep all on the engine side low under the steering shaft as inconspicuous as poss and keeping the mod inside confined to the removeable toe plate say except for poss 2 sm holes to mt the upper bracket of the pedal pivot securly to the fire wall and have the correct ratio pedeal and feel and location as poss. Then to go back stock you fill 2 holes and return the stock plate and master. Viola. I know it can be done!

In response to post 47. Sorry no name to ref by. If you do your research you will see how many makes and applications used the hydro boost. Also all discussions are for very standard, industry accepted norms for brake systems. If you look at the similarities and interchangability of chrysler mc 72-80s and gm and ford of similar eras you will see that the mounting,bores,strokes,ratios are all in these standards. We are talking 7/8- 1-1/8 bores with 4-1 or 5-1 power ratios pedals. pls look at the charts and info, If you use different ratios and then need to adj bore sizes considerably to band aid it you will have issues. There are no dramatic differences in mc strokes or bore lengths or mc casting size. Did you ck the tech info on Master powers site or piratejack?



Dan

Well maybe I can blame the day on Halloween. I received a purported NOS check valve from Merritt and planned to follow the suggestions posted on the thread. Turns out that the valve afforded no vacuum and probably was not NOS. I am sure they will send another when I return this one.
I reinstalled the old valve with Teflon tape shot starting fluid around the carb bases and intake to assure no leaks and checked idle vacuum at the carb, t- fitting to the unit and at tank and got a consistent 18 inches of vacuum at idle.
The pedal remained hard on testing with foot on pedal,and eBrake,set when the car was started. I was able to get some pedal relief by bleeding the BTV but as soon as the car was started, the pedal was again firm.
My guess is that the BTV is the problem but I will pull all four drums,to see if there is any obstruction.
I hate the thought of pulling the carpeting, brake and gas pedal to remove this BTV and send it back for refund.
I will probably talk to the guy in Florida that everyone recommended to see what he wants for a rebuild.
In the long run I would prefer to find a replacement system that affords the dual master cylinder.
As soon as I get a reply from the tech guys at HydroBoost about whether their unit with a Wilwood master cylinder with remote reservoir will work if connected to the original pedal on the 55, I will post the info.
I checked the HydroBoost on a Chevy pickup today and it runs 3 lines from the power steering pump rather than the two coming off the pump on the Packard
. Have to see if the current pump can be used.
It was a frustrating afternoon.

OK. Interested to hear how it turns out. The extra hose on the hd setup you looked at may just be a return. If that is the case you are still in good shape . Ref these hyd diagrams of the system. Return may be TEE d together. Was the 3rd hose a rubber hose n clamp or a threadded fitting?

https://www.google.com/search?q=hydro+boost+brakes&rlz=1C1_____enUS428US428&espv=2&biw=1010&bih=615&tbm=isch&imgil=WWAGGGUCWSFiWM%253A%253B_hH0vpqE6xd6PM%253Bhttp%25253A%25252F%25252Fdieselscout.ning.com%25252Fprofiles%25252Fblogs%25252Fhydroboost-your-brakes&source=iu&pf=m&fir=WWAGGGUCWSFiWM%253A%252C_hH0vpqE6xd6PM%252C_&usg=__ib-0mtRa5E5cT4CYhfCT1nWR4xU%3D&ved=0CD0Qyjc&ei=tSdWVP6oI-mBsQTfv4HADA#facrc=_&imgdii=_&imgrc=cqAoJJgj6LcrEM%253A%3BINFe_69aIF3wKM%3Bhttp%253A%252F%252Fi205.photobucket.com%252Falbums%252Fbb17%252Fben_2_go%252FMercury%252520Blue%252520Max%252520Cougar%252FhydroboostzzProper.jpg%3Bhttp%253A%252F%252Fwww.network54.com%252FForum%252F436002%252Fthread%252F1334415911%252Flast-1334587755%252Fnew%252Bbrakes%252B%252526gt%25253B%252Bhydroboost%3B522%3B560

Certainly the Gm Hydro boost is a nice compact set up. HOWEVER, studied all of the pics in the above link but could not find any pic of the pedal assymbly to determine how ez or how difficult it mite be to adapt to the Packard.

BTW. Yes, i looked at the Pirate website. Excelleent chart for pedal ratios.

Question for group with factory AC:
Can we all be in agreement that for factory AC equiped cars then a 1:1 pedal ratio is mandatory requirement????

Sorry. still not on board with the pedal ratio. But we will see what that aftermarket manuf. says. here is a short list of vehicles poss equipped with hyd boost. 1996 and newer Cobras and all V8 Mustang; gmc astro

* Most 2500 and 3500 series GMC/Chevy trucks;

* Dodge Ram equipped with Cummins turbo diesel;

* Ford Super Duty series trucks equipped with Diesel; and

* All Hummers -
I see reman units from auto parts supp at 190-285 and up. Rather than design a system with an exotic expensive part wouldnt it be wiser to use a less exp, readily avail over the counter unit for others interested and for servicability though these are fairly durable units. As it turns out ,is this a bendix unit used accross manufacturers? repl a bendix TV with a bendix HV? interesting

If I were involved in designing this retro I would
1 start with a toe plate from a doner 55. 55 and 56 are the same I assume?
2 fab a plate same size
3 examine and source the smallest unit from the list above
4 mock up/determine how high on the toe board the unit can be moved up and mounted with a single output master and dual "mini" master say the type like willwood has.
5 Determine if the assembly can be moved up sufficiently to relocate the rod to acquire the proper pedal ratio and maintain stock (or close to stock) pedal position, either with stock type pedal arm or redesigned bolt on pedal bracket and pedal assem.
If the ratio cannot be achieved this way, can it be done with the smaller aftermarket unit albeit at a greater expense.(does this unit have an accumulator and a back up reserve?) If not explore other options because if the correct pedal ratio and force multiplication cannot be achieved excessive pedal pressures, fire wall flex, toe board fatigue/failure will result, or non recommended bore sizes, fluid volume issues and improper power assist will be the outcome.

Quote:

On AC cars, any kind of replacement unit can mount no higher than the bottom of vent opening. The AC blower and ducting takes over the entire firewall and essentially the entire drivers side corner of engine compt from the opening up. For all practical purposes you are limited to the factory spot and ratio for a booster assy -- unless you get creative and modify the arm and add linkage to point the unit in a different direction. Fortunately, AC cars are so few this is not something most need to worry about.

Quote:

Thanks to the steering column right above the booster you can move upwards maybe 1-2" max unless you can change the linkage and angle the assy to point the cylinder end off to the side or find a shorter assy. I believe Craig determined a single 7 with dual master was about the optimum that could be fitted in the original space and orientation. No idea how long a hydroboost assy might be but a booster and cylinder will not clear the steering box and column otherwise. Even doing that you can only gain a tiny amount of ratio change and will still have issues getting a rod thru the floor at a higher point. Keeping and repairing the original carpet is another issue because there will be a large hole where the old rod use to be. I tried that angle approach and higher rod with my first lever experiments. That approach had promise but looked horrible on engine side.

The current way I have mine arranged moved the top end pivot of pedal up and out by extending and reinforcing the original 56 brackets. The AC evaporator box prevents more than about 1 1/2" extension in both directions. That would not be an issue in regular cars so could go higher. With that new pivot, I made a new longer arm which is angled and has the take off at the top of vent opening. The arm and pedal readily visible looks identical to stock except there is no rod thru the floor. Made an open bellcrank assy which fits entirely in the vent opening and redirects the linkage in a space between the firewall and sound deadener. It connects to an almost vertical booster assy off to the side toward the engine. That location is mostly out of sight because of the AC components and works for me with electric shift but may not work with conventional shift levers..The bellcrank being open was able to keep the airflow function for AC and still maintain the closed vent tube so no engine fumes. It all works but problem remaining is it is too sensitive. Barely touching the pedal stops the car.

That is the status now and the point where I got tired of messing with it and moved on to other projects. Not 100 percent sure where the sensitivity problem is but the ratio being around 3:1, thinking with the dual 7 1/2" unit I used it could be overboosted. Because of some concerns noted when I received the unit, it may even be a defective booster. Have a new single 7" booster to try if I ever get back to it.

It is conceivable that if a smaller and shorter hydroboost or electroboost could be mounted somewhat vertically in similar fashion, the fit and ratio problem could be solved. Without the large booster it might even work on 55 cars with shift levers & could be angled toward the fender side. I think you would still need the 56 pedal arrangement though. On non AC cars just a modified pedal and use the vent opening to mount the unit would be fairly doable.

I understand the challenges and the effort you put in already. The 7 in single may lessen the over sensitive pedal you have. I assume you still run the drums. For those undertaking a disc conv also my resources say a 7 dbl or even an 8 may bu UNDER boosted. The hyd boost unit seems smaller in over all size to the round vac booster so are you saying it may be able to move the rod up 2 or 2.5 inch? this and that sm mod to the pedal you stated may be all that is needed.
Since the 4:1 ratio seems standard for power units and all the hyd units were designed for disc drum or disc disc setups, poss a 3:1 ratio is ok for drum? I would start with a 1 in bore master then after final install and test- could "fine tune" with a 1-1/8 or a 7?8 bore master. they are cheap. Could you try a 1-1/8 bore mc on yours to alieviate your super sensitive pedal? What bore size is installed now?

Agree the discs need more pressure and volume. I believe Craig is using the 1" master with a 7" single booster on his discs but don't remember what his final ratio was -- more than my 3:1 though. If the pedal on that arrangement didn't need to be so visibly modified and relocated, IMO it would be a done deal

I am running a 1" dual master with Packard standard drums and standard wheel cylinder sizes. At the time because of the ratio and vehicle weight, was concerned the 7" single might be marginal so opted for the dual 7 1/2". That unit looked used when I got it and could well have been a return. Since there was only one company I found selling it and it took forever to arrive, I kept it. In hindsight that may not have been a wise decision. I ordered the single 7" and it sits on the shelf awaiting the mood to crawl under the car again.

If that turns out too small then I may opt for another direction and get rid of the vacuum setup and some of the extra linkage. Have been giving the electroboost a lot of thought since this thread started. Pictures I've seen of the hydroboost configuration still look a bit large for my purpose but electroboost has a remote fill pedal unit roughly 3 1/2 x 2 x 8. Keeping the basic pedal arrangement as is for the ratio, even though a bit lower than desired I think could work. Those running the electroboost at 1:1 report no stopping issues (yet) but I want the additional margin at least a 3:1 would give. With judicious plumbing and packaging I think there might be a way to mount the elctroboost remote fill cylinder higher in the vent tube area and still clear the blower assy. Have to give it some more thought and do a few measurements.

I received an email from Classic Performance that affords some clarification. HydroBoost is a copyrighted name controlled by Bosch. This is probably the unit employed by GM.
The unit to which I have referred is a hydraulic booster produced by Classic Performance CP 3100R.
The initial good news is that it is smaller in dimension than the BTV and can be mounted on an angle. The pedal ratio of 1-1 is not an issue either since the unit generates boost over 100 times the boost of the original. There is a reserve unit to provide braking in the event of stalling or hydraulic loss. The master cylinder is activated by the unit and can be a dual system with recommendation of a larger diameter piston of at least 11/4. Still need to get details on plumbing and ability to utilize existing power steering pump.
I have a number for their engineer and he believes the system will work . I anticipate that my reply will be delayed since they will be at the SEMA show this week.
I am not an engineer and frankly not that great a mechanic but I would like to assemble enough accurate information to discuss the application intelligently.
If there is a good diagram of the BTV showing dimensions and line and pedal connections, please post or direct me to the info. Someone on this post set forth the pressure output of the two power steering pumps which I hope is accurate. I believe I have a good diagram of the pump and hose assemblies for the Bendix and Monroe systems.
I would like to assemble this info with some photos and send it to CP to see if it is a viable replacement.
If preliminary findings bear out, it may afford a dual master cylinder with remote reservoir that affords safe braking with reserve for engine stall but essentially invisible.
If anyone has time to forward diagrams to me directly, the email address is rjrussell13@atlanticbb.net.
I will forward anything I gather.
Thanks
RJR