Single 7 Inch Brake Booster Master Cylinder Combo, 1 Inch Bore

#91031409

Single 7 Inch Brake Booster Master Cylinder Combo, 1 Inch Bore

Name: Single 7 Inch Brake Booster Master Cylinder Combo, 1 Inch Bore
Brand: Speedway Motors
SKU: 91031409
Price: 175.99 USD
Availability: InStock
Rating: 4.8 (55 reviews)

55 Reviews

23 Questions

Compact design adds vacuum assist for increased brake pedal response, easily mounted under the hood or floor of most vehicles
NEW heavy duty steel booster measures 7" in diameter and has a zinc plated finish for corrosion resistance
Master cylinder has a 1" bore with 3/8"-24 IFF outlets on both sides of the M/C allowing for brake lines to be run specific for your needs

Master Cylinder Bore Diameter:

1 Inch

1-1/8 Inch

$175.99

/kit

In Stock

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Product Summary

Universal Fit, 7 Inch Brake Booster Diameter

Compact design adds vacuum assist for increased brake pedal response, easily mounted under the hood or floor of most vehicles
NEW heavy duty steel booster measures 7" in diameter and has a zinc plated finish for corrosion resistance
Master cylinder has a 1" bore with 3/8"-24 IFF outlets on both sides of the M/C allowing for brake lines to be run specific for your needs
Mounting for the booster has 3-3/8" on center, 4 bolt pattern to simplify installation
Mounted overall length is 11.75"

Comes as a Kit

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Key Specs

MFG. Part #	91031409
Brand	Speedway Motors
Brake Booster Diameter	7 Inch
Master Cylinder Material	Steel

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Speedway Motors 91031409 Details

Compact for installation under floor or on firewall of almost any vehicle. Booster measures only 7" in diameter. Cast iron master cylinder has a 1" bore and is suited for disc-disc or disc-drum combinations.

Master cylinder features two 3/8"-24 inverted flare ports on each side (plugs are included for ports not in use).

Compact design to fit into small spaces under the hood
Universal in design, makes for a simple install
Heavy-duty zinc-plated steel construction to provide years of service
Uses standard DOT 3 or DOT 4 brake fluids

Learn more about selecting the proper master cylinder for your vehicle by reading our tech article. Brake System Selection.

Specs

Pushrod-to-mounting flange is 5-1/2"
Four bolts on 3-3/8" centers
Booster is 3.75" thick
Master cylinder combo is 11.875" from end of the master cylinder to the firewall
(4) qty 3/8"-24 outlet ports (2 plugs included)
8" from mount to outer edge

Guides & Documents

Effects of Master Cylinder Bore Size on Your Brake System

Master Cylinders Technical Information (91031445)

Brake Boosters Technical Information (91031430)

Speedway Motors 91031409 Specifications

KEY SPECS
MFG. Part #	91031409
Brand	Speedway Motors
Brake Booster Diameter	7 Inch
Master Cylinder Material	Steel

GENERAL
Brake Booster Type	Vacuum Diaphragm Single
Outlet Count	Tandem/Both Sides
Outlet Fitting	3/8"-24
Master Cylinder Bore Size	1 Inch
Brake Booster Material	Steel
Overall Length	11.75"
Master Cylinder Port Sizes	3/8"-24 IFF
Bolt Hole Pattern	3.38" x 3.38"
Centerline of Holes	3.38"
Reservoir Included	Yes
Sold in Quantity	Kit

Ratings & Reviews

4.8

55 Reviews

Overall Assessment

Customers highly recommend our product for its excellent quality, ease of installation, and compact design. They found it to be a great upgrade and a fit for various car models like the '56 Dodge, '49 Chev, and '37 Chevy coupe. Specific comments highlight the product's high performance, great braking improvement, and perfect fit in small areas. However, users note needing clear instructions for better usability. It's also praised for requiring minimal modifications, making it practical for those restoring older models. Repeated purchases reflect customer satisfaction and faith in the product's efficiency and top-notch material quality. A few highlighted the product's safety, stating the improved brake systems. The product stood out in its category, with many choosing it over competitors.

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4.8

55 reviews

Most Liked Positive Review

5.0

Master Cylinder & Booster

Bought to replace leaking system under the floor of my Model A. It was a direct bolt-in, all fittings and mounts were lined up and only had to fab a new pedal to booster connection. Very straight forward install, and now have plenty of brake (disk/drum). Now the car stops as well as it goes, has been a bit of a problem in the past. Should have replaced the system a couple of years ago.

Most Liked Negative Review

3.0

Booster and Master Cylinder

Lack of ANY INSTRUCTIONS resulted in me having to call the tech line TWICE!!! Even the calls did not resolve all of my issues with these units. There also should be a simple bracket to mount the booster to the firewall. I bench bled the Master cylinder, vacuum bled each wheel twice and still could not achieve a normal pedal height. Adjusted pedal push rod and booster push rod and still very low pedal.

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5.0

4 months ago

Jimmy

Maui, Hawaii

Verified

I haven't installed it yet, gotta wait for the rain to stop so we can get into the car to remove the old one

Would Recommend

Great brake package for a small space

5.0

5 months ago

Chuck

Verified

The brake set up is nice and works great.

Would Recommend

Worked great

5.0

6 months ago

Omaha

Verified

Had to shorten plunger in master cylinder but fit my application well

Would Recommend

I happy with product

5.0

7 months ago

Padeaux

Gonzales, Louisiana

Verified

Product was as expected, fairly easy to install. I'm still having issues with my brakes locking up. Haven't quite figured out what's the problem. Possibly valve. Will replace it.

Would Recommend

I have good power brakes again

5.0

8 months ago

Kevin Hotrod

Queen Creek, AZ

Verified

I purchased this for my 36 Ford Hotrod. about 20+ years ago when I got the car and new to hotrodding, the master cylinder went out. I took it to my Oreillys to match it up. I was paying more attention to the port size and location and overall appearance. I did not know anything about bore sizing. Drove it for 20 yrs with a high, HARD pedal. So, replaced everything under the floor and man, what a difference. Stops with toe pressure rather than leg pressure.

Would Recommend

Product is very flexible and effective

5.0

a year ago

Mike honcho

Dewees texas

Verified

The product went on my 1971 wagoneer and didn't seem like it would go on original brackets. Managed to get it on anyways and was able to buy some pushrod extension parts to get it to the pedal

Would Recommend

Brake system

5.0

a year ago

The 40

Palmdale CA

Verified

Goes in a 40s frame with cross member and fits great

Would Recommend

yes

5.0

a year ago

bob

Mora, MN 55051

won't use until spring

Would Recommend

Would buy again

4.0

2 years ago

Toledo, WA

Verified

Updated my brakes to front discs, exactly what I needed. Thank you

Would Recommend

I would buy this booster, master cylinder combo again.

5.0

2 years ago

Dan

Northern e

Verified

I used it to replace an old 77 Camaro set up that was leaking on my 1950 Pontiac custom hot rod. It gave me more room on the fire wall and in the engine bay. It

Would Recommend

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Questions & Answers

23 Questions • 11 Answers

Sort Questions

What happens if the the rod between the booster and master is not adjusted to the 1/16 gap? Will the pedal go all the way to the floor and not return on its own?

by Brian

• 5 years ago

1 answer

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If this booster has a 7" diameter, what does the 8" center to outer edge refer to? If the center to outer edge is 8", the is the maximum diameter 16"?

by Reinout

• 6 years ago

1 answer

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Hi I have this item and are running disc disc I have 2psi valves front and rear. The brake works but at the end of the travel the pedal goes hard and only just stops the car ( hotrod) after talking with friends I have realised I did not bleed the master on the bench first.but have bled brakes 3 times with no air coming out.also when I was bleeding them with master cap off fluid squirted up from resovoir.does this indicate anything .also I'm running a tunnel ram with 1 4bbl edelbrock carb many thanks

by Mark

• 6 years ago

1 answer

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I have a 1948 Ford F1, with a flat head 6 cyl, will this brake booster/master cylinder combo kit fit this truck?

by Kevin

• 8 years ago

1 answer

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Would this set up work for a 1958 Ford F100? If not what set up would work?

by Austin

• 8 years ago

1 answer

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Will this unit bolt up perfectly to the fire wall of my 1961 Ford f100 pickup, if not what unit would you recommend?

by mort

• 8 years ago

1 answer

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I see by another question on here that a recommended master cyl/booster kit for a 1950 F1 Ford pickup is a #91031409. My '50 F1 has a big engine/radical cam and I don't have the vac needed for power booster and don't want to install a vac pump. I do need to update my master cyl though. Can you tell me what part number I need for a manual master cyl update? (for disc/drum setup) Thanks.

by hillcogolfer

• 8 years ago

2 answers

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I bought this product about a year ago and I am just now getting around to installing it. I took it out of the box and saw that I do not have the slug that goes in the backside of the master cylinder to take up the deep hole for the push rod. Do you sell the slug or cylinder and what is the size I need? Thank you.

by Jeff

• 8 years ago

1 answer

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Hello,I bought an master sylinder with 4 ports.Is IT possible to use one front port to the right front wheel and the other front port to the left front wheel ?

by Petter

• 8 years ago

1 answer

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I did purchase the under the dash mounting assembly for my 1954 chevy wagon from Speedway to relocate the master cylinder from the stock floor location and mount on the firewall. I now need a master cylinder/power booster for the 4 drum brake system what else will I need to complete this brake system a switch,proportioning? Thanks

by 2 Feathers

• 10 years ago

1 answer

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