Has anyone done that?  Thinking of doing that and would like to call on anyone who has and what problems I could encounter.

The OEM booster is not sufficient for all four corners, when converting to disc brakes. It can be used for the front or rear, if you are converting to a dual-circuit master cylinder as well. you will need an aftermarket booster for all four corners, which will require relocating the battery. 

I can't speak for the booster but can say that I have front discs and rear drums on my 55 Bird for the last 25 years. My pedal is hard and the effort is way less then the original with all drums and stops way better. So I would say try it without a booster and you can always add one if you need to. You can always size the master cylinder and calipers to increase force also.

  Vic Correnti

I bought a front disc/power booster kit from one of the Thunderbird supplier (they retired, I think Hill’s acquired them) back in 1999. It used a disc/drum dual master and the booster on the front disc only. I don’t recall if there was a different rear wheel cylinder (for balance adjustment) or if it would be different with the front booster. But most of the bird suppliers would know.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Vic, glad to hear you are happy with your brake setup. I bought Wilwood 4-piston Dynalite calipers and 1 1/2 drop spindles from Dave (Drop em Stop em), Wilwood 15/16ths master/w proportioning valve, retaining OEM 11" rear drums, but no booster. I'm still working on put my 55 back on the road, but it sounds like I'll be happy with my brakes. I do intend to put automatic adjusters on the rear and can provide parts list for same if you're interested. PM works for me.

Not on a Thunderbird but I installed the Wilwood 7/8” MC, prop valve, and 4 piston calipers on my 56 Victoria and 11 x 2-1/4” F-150 rear drums on the 8.8 rear I installed. No booster and it stops great. Pedal pressure is less than all drums.
At a Thunderbird gathering I noticed quite a few with front discs and a Bendix Booster on the left fender and found out Prestige Thunderbird in Sante Fe Springs Ca. does this installation. They use the 4 piston front Mustang calipers. The owners I talked were very pleased. I see no reason not to add this style of assist if you feel it’s necessary with the Wilwood calipers. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I have heard that running the stock booster on just the front brakes (disc) is something many people do.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

According to Gil Baumgartner ay CTCI , using the stock booster for the front disc brakes wont help at all because it can provide a 600-800 psi assist and front disc brakes require a boost of at least 1200 psi to provide a noticeable assist.

Disc brake calipers are designed to operate at higher hydraulic line pressure than original drum brakes, as a result it is very beneficial to have a power brake booster. These steps are written presuming you have a power booster on your car. If not, the brake fluid lines would be slightly different. A booster is highly recommended. Even with a booster these brakes will not give you the feel of the disc brakes on your new vehicle, it still takes a bit of pedal pressure. The biggest advantage is the straight, true stopping, and the resistance to fade.

SOURCE - https://www.ctci.org/disc-brake-conversion/

A MIDLAND BOOSTER is designed for one circuit only as was common in pre-1967 cars (SGL RESVR MC). To keep the disc conversion somewhat OEM appearing, the front disc circuit (primary reservoir) will be plumbed through the BOOSTER HYD CYLINDER for disc power assist and the rear drum circuit plumbed straight from the MC secondary reservoir as they require less line pressure their being self-energizing.

The original kit design included different size rear wheel cylinders and was later changed to a universal PPV. Both methods seem to be hit and miss on brake bias. The booster will give enough assist to be noticeable.

The nice thing about this conversion is that the KH 4-Piston Caliper can be adapted to the OEM spindle (and keep original 14" wheels - 57 BIRD) and can be easily changed back to 4-wheel drum if the car goes to a dedicated restoration.

CTCI Install Photo Showing Rough Plumbing -

____________________________

I did a Granada conversion on my 54 Ford.  Went non power.  Used the Granada dual master for non-power brakes.  Brakes improved with stopping and don't miss the power set up at all.

A friend with a 56 Bird just went to front discs, non power.  As far as I know, he is very happy with it.  I think he used the 4 piston calipers.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ