Second in a Series DIY Bendix Tredel-Vac Restoration. Vacuum Booster ...

[Continental59]

Second in a Series DIY Bendix Tredel-Vac Restoration. Vacuum Booster ...

[Barry Wolk]

Great write up. Thanks for that. I believe that this is the "sleeve" type of booster that was abandoned early in production. They replaced it with the "poppet" type Treadle-vac. I understand that the latter makes the brakes quite grabby, if that's a word.

I had mine rebuilt by Ed Strain in Florida, and it's done something strange ever since. If the car is at idle at a light with the brakes applied the engine will stumble. Take your foot off and the engine purrs. Does anyone else's car do that?

I'd love to make that go away.

Also, how do you test the vacuum valve on the side of the unit?

One hint. If your car is restored, make sure the vacuum lines are actual vacuum tubing and not gas line. Gas line will collapse, leaving you with little braking power.

[Mad Scientist]

Excellent write up! Thank you for sharing.

If I were to rebuild one I probably would have honed the master cylinder.:(:eek:

[Nick DeSpirito]

Ditto, Continental59, Thanks! The pictures also give us an idea of exactly how the unit operates. Many thanks!

You mention that there are two types of cylinders. Can you explain the difference between them and why they used two?

[Barry Wolk]

Nick, the two types were sleeve and poppet valve. I'm not sure which one this is.:o

[Nick DeSpirito]

Me either. :o Is there a physical difference?

[depmike38]

This is great. I was going to send mine out but with this I can break mine down and repair it at home. I may have missed it to begin with but is there a source for a kit or did you make all of the gaskets/seals, etc?

[Barry Wolk]

Me either. :o Is there a physical difference?


Not externally.

[Continental59]

Yes a big difference it is physically larger is diameter. Inside there are "pop" valves I have a carcass or two laying around....However they are interchangeable with the master cylinder....

[Barry Wolk]

I have never seen a Mark II with a larger diameter booster.

[Barry Wolk]

I have confirmed that this is the sleeve-type. What I don't understand is what it's doing on a '59. I might be wrong but I was led to believe that the sleeve unit was used early on and changed to the poppet-style, pictured below.

I wonder if someone fitted a sleeve-type to the '59 as a retrofit, or did Lincoln go back to the sleeve type due to its smoother operation?

I did get something useful about of this pictorial. I don't think that mine has hose clamps on the horse-shoe vacuum hose. I remember that the hose connections were quite loose.

http://i244.photobucket.com/albums/gg18/barry2952/1%20Mark%20II%20docs/Scan1-2.jpg

[Nick DeSpirito]

Barry,

I think I have the one in this illustration you posted. I have that little tube thingy on the back of the cover of the reservoir too, unless the other style has it too? Since the filler cap is screwed on, I guess it's to let air in the master so the fluid can drain as needed?

[Barry Wolk]

Yes, our system is open to atmosphere. All the more reason to change brake fluid every 2-3 years. Brake fluid is hygroscopic. It picks up water molecules. Like all other water and oil situations, water will accumulate in the lowest portion of the system, the wheel cylinder.

Next time you bleed your brakes, save the changed fluid and let it set. When the water separates and falls to the bottom you'll see why brake cylinders corrode.

Getting rid of old fluid every 2-3 years will prevent damage and restore a spongy pedal to normal. Brake fluid is not compressible. Water is.

[depmike38]

:)Considering that I seem to have A) a spongy pedal & B) a car that has sat up for about ten years I'm getting a bad feeling about my brakes from all of your info. As I've never had another treadle vac system this is all going to be verry handy.

[Barry Wolk]

I love my brakes. They are the best of any pre-disc car I have ever driven.

There is probably some brake cylinder damage if it sat that long. You might want to inspect for rust damage. Replacement cylinders are available as are rebuild kits.

One real important item is replacement of the hardware kit. Springs may look fine, but lose the ability to quickly retract brake shoes. I learned a very expensive lesson once and feel obligated to share it. Hardware kits are cheap, brake drums are not.

Another important aspect is something that goes undone in a brake job these days, arcing of the shoes to match the drum. Actually, they should just slightly rock in the drum. Doing this insures that you have the maximum brake shoe contact, right from the beginning. Wearing in shoes without proper arcing often glazes the shoes, further diminishing the ability to dissipate heat. If your shoes and drums shoes are still good, keep them matched to the drum they came out of.

Pay attention to your hoses. While in park, with the motor running, have someone apply the brakes as you firmly grasp the rubber hose at each front wheel and the differential hose. If you feel expansion of the hoses, replace them. That's where braking capacity is lost and show signs of a future problem.

If your brake lines are in good shape, flush them out with acetone. Rig up a drip so that the fluid passes through the metal pipe work slowly, letting its vapors and fluid cut and flush away contaminates.. I would not flush the rubber hoses as the acetone will make the rubber swell. If I didn't know the history of the brake hoses, I'd replace them as a matter of course. Rubber hoses can clog up and reduce flow that's critical for even braking.

Grease the bearings with high temperature grease. These are pretty heavy cars. New grease seals to protect your hard work, and you're ready for the road.

I don't believe you can spend too much time or money on your brakes.

[2MarkIIs]

Any idea where the write up for this went to?

[Pat Marshall]

Continental59 said it was deleted from Forum. However, he told me where to find it!

http://ford-mel-engine.com/viewtopic.php?f=12&t=150&p=435&hilit=DIY002#p435

[2MarkIIs]

Awesome help Pat, thank you very much