General Bendix Treadle Vac Question

[MBL]

Also remember!!!!I was able to find that the VW brakelight switch functions in the same way the original T-L switch does and for like 7 bucks.

Tim

MBL

[Karlel]

On the side of the Honda master cylinder:

3D4 13/16 NISSIN

On the side of the power cannister:

type: NM-205V-3

NISSIN KOGYO

UEDA Japan

[Guest imported_PackardV8]

ok, that jives close to mine: 13/16 on cylinder.

Master Power. type:NM 180V. 40S22 2791. Nissan Kogyo. UEDA Japan. on power unit.

I'd still prefer a master cylinder closer to 5/8 but for right now this Honda unit works just fine. DO NOTE that u will need to keep the brake shoes adjusted due to the lesser travel of the Honda unit.

[Karlel]

Well, that's good to know. I just went to the winter storage to look for the diameter of the Packard lines. The diameter of the Honda lines are 1/10 millimeter smaller (0,025 ") then the ones on the Packard but perhaps this is due to dirt. I cannot imagine there are breake lines with this small difference.

If there is a difference like this it wouldn't matter because the (double) flare would compensate this.

[Guest Albert]

The brake lines are the same size on both the Honda and the Packard they both use 3/16, Another method you can use to make a short line with a metric fitting on one end and sae on the other, then use a coupling to join them, or the sell adapters that will screw directly into the master, and give you a female 3/16 SAE line that you can connect directly to the Packard lines

[Karlel]

Looked under my 53 Clipper, saw that the break fluid reservoir of the Honda power/master cylinder unit cannot be installed on the unit. The steering column is in the way, so I'll have to install a remote reservoir. Is there some kind of tube I can install on the master cylinder, so I can fix the reservoir on top of the tube? Anybody a good solution for this one?

[Guest imported_PackardV8]

1. i tilted my civic unit so that the reservoir is pointing toward the fender antenna on an angle. BUT, i eliminated the fresh air tube that runs from the front of the car to the firewall because i have air conditioning. If the fresh air tube is not eliminated then u will probably have to go with the remote reservoir.

[Karlel]

Just removed the Treadle Vac. Drilled new holes for the Civic power unit but it won't fit.

The accelerator rod bracket, mounted against the firewall, is in the way. The shell of the TV vacuum cylinder has a diameter of about 5,5" and the shell of the Honda vac. cyl has a diameter of about 8,5". So the bracket is in the way. How was this problem solved??

[Karlel]

Never mind, I made a mistake. I own a 1953 Clipper. No wonder it doesn't fit. Now I'm stuck with a Honda booster (fitting a a 1956 Clipper) and 4 holes in my fire wall. Stupid, stupid. The booster of the Panther Project won't fit either because it is too long.I'll just rebuild the TV. I've already got a TV overhaul kit. All I need is a new master cylinder piston. I'll buy one at Kanter's. Mine is a little pitted.

Charles

Charles

[MBL]

Did you take a look at how I did mine. Go to a parts store and have them pull a booster for you so you can take a measurement.

Tim

MBL

[WCraigH]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Never mind, I made a mistake. I own a 1953 Clipper. No wonder it doesn't fit. Now I'm stuck with a Honda booster (fitting a a 1956 Clipper) and 4 holes in my fire wall. (snip) </div></div>

There shouldn't be a difference between a 1953 and 1956 as far as the brake mouning is concerned. On the Panther Project, the MPB booster & MC mount to the toe plate, NOT the firewall, as per this picture:

[Karlel]

Read all about the failure of the Treadle vac. I just took apart a TV. Looking at the parts of the TV I cannot imagine how it is possible to suddenly have no brakes due to the TV. Reasoning in the most simple way, is it is nothing but the break pedal pushing the piston into the master cylinder. This displaces the break fluid into the brake lines, even without a working vacuum system. That's it.

So I cannot imagine why anyone can push the break pedal to the floor with no brakes if:

1. The rubber piston seal is in good condition

2. There is enough brake fluid in master brake cylinder.

3. The piston itself is in good condition.

No vacuum doesn't mean no breaks. You only need more force on the pedal.

By the way. I drilled a little hole in the center of the fluid reservoir cap.

and pressed in a tapered pin with some marks on it. That's a good dip stick.

[Guest imported_PackardV8]

"Reasoning in the most simple way, is it is nothing but the break pedal pushing the piston into the ..."

Sure seems that way doesn't it?! BUT, u missed one other critical item: there is a small spring loaded valve that goes between the reservoir and the ram (piston) chamber. The parts ARE very simple for rebuiling the Master cylinder thats true. BUT look at the price and availability of the parts to do it.

[WCraigH]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">(snip) So I cannot imagine why anyone can push the break pedal to the floor with no brakes if:

1. The rubber piston seal is in good condition

2. There is enough brake fluid in master brake cylinder.

3. The piston itself is in good condition.

(snip)</div></div>

The problem is that [color:"red"]WHEN the rubber piston seal leaks, the brake fluid gets sucked up into the engine in rather short order. Below a critical level, the brakes fail completely with no warning! [color:"red"] BELIEVE IT! There is virtually no warning and no reason to check the fluid level. And even if you did check the fluid level, it would look OK immediately beforehand.

I've said it before and I'll state it again emphatically: the Bendix Treadle-Vac is a fatal accident waiting to happen. Imagine the litigation in today's society if the BT-V were manufactured in recent times. <img src="http://www.aaca.org/ubbthreads/images/graemlins/mad.gif" alt="" />

[RO]

Man, can I TESTIFY to the instant brake fluid sucking into the engine!!! Happened on my ill fated '56 Custom. I had driven over to the muffler shop and back with NO problems at all, but when I pulled into the driveway and started my turnaround, the brakes went to about nothing and I cleared out all the mosquitos over an acre. Big white cloud out the tail pipe. I had virtually no brakes at this point. What was left mechanically was practically useless. The master cylinder was dry, nothing, not a drop.

[WCraigH]

As further testimonial to this problem:

1) I've had it happen to me 3 times on 3 different BT-Vs. The first time was instantanteous; one application was OK, the next was NO BRAKES. The 2nd time was a slow leak that allowed me to slowly drive to a shop. The 3rd time was driving locally and within about 3 pedal applications, the brakes were gone!

2) At least 5 other Packard owners that I have personally communicated with (3 by email, 2 face-to-face) had the same problem. One second, brakes are OK, next second, no brakes.

IMO, in the face of this evidence, anyone who retains the BT-V is risking life, limb and at the least, the metal on their Packard.

BTW, the Bendix Treadle-Vac was also used on Pontiacs, Edsels, Fords, Mercs and AMC during the 1950s. There's a good reason why all these manufacturers (who were still in business) quit using the BT-V and switched to something reliable.

[Karlel]

I wonder if the MPB power brake set up of the 1956 Packard Panther project fits a 1953 Packard as well. I just finished rebuilding the T V , but still I don't feel happy about the system, especially after all the comments.

[WCraigH]

I don't see why not. 1951-56 are all "High Pockets" bodies and even through the 1951-54 don't have T-L, the frame & steer column should be the same, per the pre-install pic I posted above.

However, be aware that if you use the MPB, you [color:"red"] MUST change the pedal leverage from 1:1 to at least 3:1. The shoe brakes, being self-energizing, don't require as much pedal pressure as the disc brakes I'm using, but I doubt they'll be enough line pressure to give you the pedal feel you want.

Maybe somebody has installed a MPB with drum brakes and can comment...

[Karlel]

That's it. I'll order the MPB set, used on the Packard Panther project. If there are any special remarks, I'm open for them.

[Guest Albert]

I'am also not that comfortable with the btv, I rebuilt mine in Feburary and a couple of weeks ago they slowly went to the floor. The rubber O-ring in the top of the master cyl that holds the poppet valve started leaking.. but not before i had rolled down a drive way onto a busy street in rush hour, my friends 55 clipper has done the same and now sitting in my driveway waiting to be fixed or sold..

[RO]

EVEN rebuilt along with other new components like wheel cylinders, lines, etc., I have to refill my treadlvacs more often than on any other car. The fluid must be being sucked up into the carburetor because I have no external leaks and it does it on the '53 and both '55s. I have to add fluid about every 200-600 miles consistently among the three cars.

[Guest imported_PackardV8]

Albert wrote: "I rebuilt mine in Feburary ... The rubber O-ring in the top of the master cyl that holds the poppet valve started leaking.."

I'm assuming this is the valve between the reservoir and the ram chamber????

Did u replace the offending o-ring or poppet when u did the rebuild???? If so, where did u ever find one???? I believe that this particular valve is the problem with the TV causing brake failure.

[Guest imported_PackardV8]

i have a BTV master cylinder here that i am disassembling for further analysis. I'm not sure that there is anything inherently wrong with the design or function of the cylinder other than the availability of a COMPLETE kit to rebuild it not to mention the exhorbant cost of whats available now to be just a partial rebuild .

[Guest Albert]

Yes V8 it was the o-ring between the resovor and the ram, all those parts are part of the kit Kanter sells.

[Karlel]

I'm gonna send a fax to MPB asking the best booster/master cylinder set up for drum brakes to replace the BTV. I'm not that familiar with replacing break systems. So I leave it to professionals. I'll wait and see.

[WCraigH]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I'm gonna send a fax to MPB asking the best booster/master cylinder set up for drum brakes to replace the BTV. </div></div>

I expect you'll get the answer that they don't have one.

The booster I used was originally designed for "street rod" use. They may also warn that you need a proportioning valve and an anti-siphon valve. Don't need 'em.

MPB was supposed to be coming out with a dual diaphram varient of their 7" booster that would provide more line pressure. However, there isn't room for it, which is too bad. It might alleviate the need for a reworked pedal leverage.

Let us know about their response.

[Guest imported_PackardV8]

In your fax to MPB be sure to indicate that the Packard Bendix cylinder is a 5/8 inch cylinder (actualy its 0.655). NOTE that the Packard manual indicates it is a 1.00 inch cylinder but that is simply NOT true. There is absolutly NOTHING 1 inch about it. I'll have mine apart in a few hours from now for analysis and measurements.

[Karlel]

Mind this!! I keep my drum brakes at all four wheels.

Am I right when I think I only need (to replace the TV):

*the remote reservoir master cylinder & kit

*the 7" booster

*one 1/2-20 brake adapter

*one 9/16-18 brake adapter

*a push rod w eye

as mentioned in the Panther project.

(Oh boy, how I love this forum!!!!!!!!!!!!!!)

After your answer I'll ask MPB my question

[WCraigH]

I really admire the courage of some of you guys who overhaul and use the BTV. This theory, that theory, maybe this part, maybe that part, how about this brake fluid or that brake fluid...

The [color:"red"] FACT is that for whatever reason, the Bendix Treadle-Vac [color:"red"] WILL sometimes catastrophically fail without warning. If the driving cirucumstances are not benign when that happens, something worse than inconvenience will occur. I don't have that kind of courage.

[WCraigH]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Mind this!! I keep my drum brakes at all four wheels. Am I right when I think I only need (to replace the TV): (snip)</div></div>

That seems right. You keep all the original brake lines, but be sure to bleed them to flush out all the old brake fluid. Adjust all the drums and the parking brake per the service manual.

Once the conversion is completed, test drive it very carefully with no traffic or hills to make sure you can generate enough line pressure with the 1:1 stock pedal. If not, alter the pedal leverage per the Panther Project.

[Guest imported_PackardV8]

Craig wrote:

"generate enough line pressure with the 1:1 stock pedal. If not, alter the pedal leverage per the Panther Project."

YES!!!! and thats why i keep barking about the bore size of the retro unit chosen. Mine is a Masters unit nearly identicale to Craigs but mine came from an late 80's or early 90's Honda Civic wit h a 13/16 bore and my pedal is a bit hard. All the rest of my brake system is Packard. So anything greater than the 13/16 i have will just get damned harder faster.

[Karlel]

CraigH,

Next monday I'll send a fax to MPB. I'll let you what their answer/advice is, if I get any. I'll also refer to the Packard/Panther project, unless you don't want that.

[Guest imported_PackardV8]

BOE: One other thing to note is that the Masters unit i have (and i assume the one that Craig has too) has a shorter stroke than the Packard unit. This is somewhat of an issue trying to get the trade off between stroke and cylinder diameter. The smaller the cylinder diameter then the more stroke on the pedal is needed.

[Guest imported_PackardV8]

The Bendix cylinder has a rather peculiar vent from the reservoir to the OUTER seal of the ram. This vent is more precisely a brake fluid gallery that allows fluid to the OUTER seal of the master cylinder at the ram to keep it lubricated. The vent is ONLy noticeable when the reservoir COVER (not the cap) is removed. So, if there is vacuum leakage from the power unit to the cylinder then it is quite possible that the fluid could be sucked from the reservoir. I see nothing really wrong with the cylinder design but the power unit is a real monkey motion set up.

[Guest BigKev]

I dont mean to reopen an old thread here but I have a question. Would something like this work/fit to replace the Bendix unit (obviously some drilling may be needed for mounting). It looks like a pretty small unit that might fit where the Bendix unit sits now.

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=192851&prmenbr=361

Thanks,

[Guest imported_Speedster]

The master cylinder needs to be mounted level, with that type assembly.

Not enough room under steering column to do that.

You can use a remote reservoir type master cylinder.

It may be easyer to convert to the type unit that mounts behind dash at a 90deg angle, since you will probably want to put in new brake lines anyway. They are completely hidden from view but are hard to refill master cylinder, unless you cut a hole in top of dash and install some kind of cover. But, they can be refilled without the hole in top of dash, just very hard to do without dripping some fluid on carpet. The Pedal assembly would have to be modified also, no matter what type conversion you do.

[WCraigH]

Remote fill master cylinder is what I used on my 55 Patrician. See my website for pics & details.

7-in diameter is about as big as you're going to be able to install.

A dual diaphram will help with the pedal pressure, but I had to devise a 3:1 pedal lever to get enough force. Again this is pictured on my website.

For my Panther, I'm going to use a firewall-mounted Delco unit from a big Chevy. Of course the dash and everything is removed. I wouldn't attempt this otherwise.

[Guest imported_Speedster]

I was wondering if putting an inline fitting, with a very small pin hole, in the vacuum line to T-V, would slow down the brake fluid being pulled from master cylinder, in case of a failure ? Exhaust smoke would let you know there was a problem, giving enough time to safely stop.

If the hole happen to get pluged, you would only loose power assist, which would be better than loosing all brakes very quickly. A small inline filter could also be installed ahead of the orfice fitting, to keep it clear.

[Guest imported_Speedster]

I found a small natural-gas type valve that I'm going to put in vacuum line.

That way I can control the amount of air getting thru. I'll open it just enough to let brakes work okay. <img src="http://www.aaca.org/ubbthreads/images/graemlins/smile.gif" alt="" />

[Guest BigKev]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Remote fill master cylinder is what I used on my 55 Patrician. See my website for pics & details.

7-in diameter is about as big as you're going to be able to install.

A dual diaphram will help with the pedal pressure, but I had to devise a 3:1 pedal lever to get enough force. </div></div>

So if I got this unit and did a remote fill master cylinder, would this unit work? With a dual diaphram would I still have to modify the pedal?

I am trying to figure out the best solution without breaking the bank. I would like to keep it as stocking 'looking' as possible, but without the inherit problems of the Bendix unit. Isn't there some kind of check value that you could put on the vacuum line to keep the Bendix unit from sucking fluid? I noticed that all the bendix rebuild kits offer a leather piston cup seal for an extra price. I am suprised in all these years someone hasn't found a more durable material.

If you had some kind on a catch can on the vacuum line with a float or something in that block off the vacuum line if it got fluid in it that should work. *Wishfull thinking*