disc coversion k/H under dash puzziled

[jacob80]

Alright guys, I took yellowbird's advice and pulled the trigger on the ABS Power Brake unit. The guy there knew exactly what I needed and hooked me up. I suggest this route for anyone else that wants front disks with the under-dash booster. Very relieved to have finally found a solution for this **** brake kit!

**** you SSBC!

[Astrowing]

Are any of these AC equipped cars? How much does the bracket move the assembly up and away from firewall?

[simplyconnected]

Are any of these AC equipped cars? How much does the bracket move the assembly up and away from firewall?

Howard's is a 430 w/AC. The bracket moves the booster up five inches and out from the firewall five inches.

Squarebird's original manual M/C mounts on the firewall so low, it has its own bolt pattern (and part number) which is not shared with full size Ford cars. Directly below the M/C is your steering linkage, making a 10" booster retrofit impossible without moving it.

[Guest]

Same situation here. I am in the process of gathering parts for my front disc brake conversion, Scarebird bracket etc. The ABS company master cylinder that yellowbird used does that require the special bracket to mount to the firewall? I have an AC car with the Kelsey Hayes under dash power brake unit.

[Astrowing]

Ok, does the ABS bracket raise and project 5 and 5 and does the 4 bolt m/c pattern match that of 58 with under dash k/h?

Or is the 4 bolt pattern different on full size Fords? Did full size Fords ever have a under dash k/h?

Pictures and dimensions would be great if anyone has one.

[simplyconnected]

Jim, many cars used the same 'bellows-type, variation 1, Kelsey-Hayes booster:
1956-61 Chrysler
1956 Desoto
1956 Dodge
1959-60 Edsel
1957-1960 Ford
1956-61 Imperial
1957-61 Plymouth
1958-59 Squarebirds

It does not interfere with the brake pedal rod or the M/C. In fact, it is connected to the Brake Pedal itself and it uses vacuum to help pull the pedal. When the pedal is depressed, it opens a valve. The more you press, the more the assist (so it is a proportional servo valve).

This booster never worked very well so Ford dropped them in favor of the Bendix booster and never went back. All the other manufacturers followed suit. For the consumer, to have a car with 'POWER BRAKES' was a big deal back then. Even the full-size Ford cars came with manual brakes.

Now that we understand that this booster is independent from the M/C, YES, the ABS firewall bracket has slotted holes that fit the bolt pattern of a Squarebird OR full-size Ford. Yes, it hikes the booster up and out 5"-and-5". The four-bolt pattern on full-size Ford M/Cs is spread out a little more, top to bottom. That's why Squarebird M/Cs have a different part number. - Dave

[Guest]

Just got off the phone with ABS. They did confirm that the part number for master cylinder and booster was 9787 Price today was $325.00. My question is when I asked the tech about the kelsey hayes under dash booster he said we needed to remove the entire unit and use the booster they supply for the firewall. Could the kelsey hayes unit stay in place and work alongside the brake booster on the firewall or will I have to disconnect the unit?

[jopizz]

You do not need to remove the KH booster under the dash. Ray Clark and others have left theirs in place and haven't had any issue with it.

John

[Guest]

Hooked up and connected?

[jopizz]

All it does is assist the brake pedal. It has no connection to the master cylinder or the new brake booster you will install. You can leave it connected. It won't help or hurt anything.

John

[simplyconnected]

Dan, it's personal preference. You can leave it connected or you can remove the whole thing.

1960 Thunderbirds don't have the bellows booster at all. So I doubt if anyone will be looking for yours. Booster Dewey told me that the materials back then were really bad and that these boosters simply failed from age. They are not cheap to rebuild because of supply and demand.

The real point is, they don't help much. Everything you need will be in the new booster including the reservoir (vacuum chamber) and check valve.

It's your car to do what you wish. Someone told me that they couldn't tell a difference when the bellows was connected or when it wasn't. You can do the test on your car. If it were my car I would take the bellows out. It's just another thing that can go wrong and I don't want to fight the thing if it stops working.

I should tell you that most of us are using the same type (Corvette) M/C BUT ours have a 1" bore, not 1-1/8". The one inch makes an easier pedal but the larger bore uses a shorter stroke. I have tried them both and I prefer the one inch M/C. - Dave