Single Diaphragm Power Brake Booster, 7 Inch, Chromate Finish

#91031430

Single Diaphragm Power Brake Booster, 7 Inch, Chromate Finish

Name: Single Diaphragm Power Brake Booster, 7 Inch, Chromate Finish
Brand: Speedway Motors
SKU: 91031430
Price: 156.99 USD
Availability: InStock
Rating: 5 (15 reviews)

15 Reviews

12 Questions

Compact for installation under floor or on firewall of almost any vehicle
Single diaphragm booster measures 7" in diameter and fits in the tightest spaces possible
Booster has four bolts on 3 3/8" centers which fits a variety of mounting brackets and pedal assemblies

Booster Type:

Single

Dual

Finish:

Zinc

BlackChrome

$156.99

/each

In Stock

Garage Sale alternatives: from $125.99

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Product Summary

Universal Fit, 3.70" Overall Thickness, Steel

Compact for installation under floor or on firewall of almost any vehicle
Single diaphragm booster measures 7" in diameter and fits in the tightest spaces possible
Booster has four bolts on 3 3/8" centers which fits a variety of mounting brackets and pedal assemblies
The length 4 bolt mounting face to master cylinder mount face is 3-5/8"
Zinc plated for corrosion resistance

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Key Specs

MFG. Part #	91031430
Brand	Speedway Motors
Outside Diameter	7"
Material Type	Steel
Finish	Zinc Plated

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Need To Know

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Installation Details

Installation Tips

How to test your brake booster vacuum:

The valve where the vacuum line plugs in is a one way valve and is the first thing to check. Next with the car not running pump the brakes several times to remove any residual vacuum in the booster. Now push the brake pedal firmly down and hold pressure on the pedal, start the engine and when the vacuum reaches the booster the pedal should go down slightly. If it doesn’t move at all or if it goes down over an inch or more there is probable cause for concern. Next install a vacuum gauge in the line at the booster, start the engine and check the available vacuum. For full assist you need 18-20” of vacuum available.

This booster accepts master cylinders designed for a boosted brake system that have 3-3/8” center to center mount pattern. Depending on the application Speedway offers 1” bore GM style master cylinders for the front disc and rear drum vehicles under part number 91031445 or for the four wheel disc applications we offer a 1-1/8” bore master cylinder under part number 91031440. We also carry several other options in chrome, polished aluminum, and performance versions from CPP.

Installation Note: Before installing the master cylinder onto the booster, you may need to make an adjustment. The pushrod on the brake booster should protrude 1/16" from the face of the booster to insure proper engagement with the master cylinder.

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Speedway Motors 91031430 Details

Single diaphragm boosters are compact for installation under floor or on firewall of almost any vehicle. Booster measures only 7" in diameter. Zinc chromate finish. The single diaphragm is usually used on lighter vehicles. In the heavier applications of 3000-3500 pounds or more we normally use the dual diaphragm boosters.

You will need full manifold vacuum available to the booster. Manufacturer requirements vary between 18 and 20 inches of vacuum. With radical cams there are many cases where there is a loss of the necessary vacuum and the only option is a 12 volt vacuum pump available from Speedway under part number 91028146.

O.D. is 7" Length from mount surface to master cylinder mount surface is 3-5/8" (this does not include the shoulder that extends into the master cylinder)
3/8 x 24 thread pushrod that is 4" long from mount surface to end of the threads (pushrod nut included)
4 bolt mount pattern on 3-3/8" centers
Mount bolts are 5/16 x 20 and 7/8" long and nuts are included
Master cylinder mount studs are 3/8 x 18 and 1-1/16" long and 3-3/8" on center

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

Charts

Booster Tech Tip (GIF)

Guides & Documents

Brake Boosters Technical Information (91031430)

CA Prop 65

Speedway Motors 91031430 Specifications

KEY SPECS
MFG. Part #	91031430
Brand	Speedway Motors
Outside Diameter	7"
Material Type	Steel
Finish	Zinc Plated

GENERAL
Overall Thickness	3.70"
Bolt Hole Pattern	3.38" x 3.38"
Centerline of Holes	3.38"
Brake Booster Type	Vacuum Diaphragm Single
Sold in Quantity	Each
Notes	Length from mount face to M.C. mount face is 3-5/8". Pushrod extends 4" from mount face and has 3/8"-24 threads. Mount bolts are 5/16"-20 x 7/8". M.C. mount studs are 3/8"-18 x 1-1/16".

Ratings & Reviews

15 Reviews

Overall Assessment

Reviewers praise the product for its excellent quality, practical use and high performance in various vehicles ranging from a '63 Nova SS to a '30 Model A Pickup. Its compact design enables fitment even in minimal space without compromising functionality. The product is appreciated for working perfectly right upon installation, indicating ease of use and reliability. Its compatibility with different vehicles exemplifies its versatility. The product appears to be recommended for its perfect fit, easy adjustment and operational success, with many customers inclined to repurchase for future needs, signifying high customer satisfaction.

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15 reviews

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Yes

5.0

a year ago

Pres

Gainesville, Ga

Verified

Replacement Booster 1934 Ford Streetrod

Would Recommend

Great fit.

5.0

a year ago

Verified

Love the size it's going in a very tight area again. Going to work out great.

Would Recommend

I would definitely buy this booster again

5.0

2 years ago

Bill

Miami, Fl.

Verified

Everything on this booster was correct. No installation problems.

Would Recommend

.Great product at a decent price.

5.0

2 years ago

JAKE

western Iowa

Verified

I installed this on a 1963 Nova SS. It now has a V8 and auto trans.

Would Recommend

I would buy again

5.0

3 years ago

Hot Rod Lane

Sheridan Mi

Verified

it worked when installed, doesn,t get any better than that

Would Recommend

I would definitely buy this booster again

5.0

4 years ago

Rooster

Panama City, Fl

Verified

It fit perfect and works great.

Would Recommend

If I needed another I would buy this again

5.0

5 years ago

Glwhite

Shellsburg iowa

Verified

Bolted right up on my 42 ford business coupe and worked great

Would Recommend

I would buy this product for future projects

5.0

5 years ago

racerdave

Lake Havasu city az.

Verified

I was worried about the small space I had to work with but it clears all other components just fine

Good quality in a compact size ! Worked perfect !

5.0

5 years ago

Eduardo

Elephant Butte, New Mexico

Verified

The booster worked perfect to operate the rear brakes on my V8 trike project.

Would Recommend

Great quality parts!!

5.0

5 years ago

DrC10

Tucson az

Verified

Worked great in a 68 Jeep with only minor modification. Priced well and shipped rapidly... another win for Speedway!

Would Recommend

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Questions & Answers

12 Questions • 10 Answers

Sort Questions

I have this booster in my 53 Chevy truck and the rear plunger seal just tore and is leaking vacuum. Is there a replacement seal available? Or do I have to purchase a new brake booster?

by Jeff

• 7 years ago

1 answer

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I have a 7" single Diaphragm brake booster. I have some play in the pedal. What can i do to correct this. it is mounted under the cab. Thanks, Joe

by Joe

• 8 years ago

1 answer

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Will this booster work with the T,A and 32 pedal master cylinder kit you sell ?

by Thomas

• 8 years ago

1 answer

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this booster ships with a rubber plug in the M/C hole. Is it for shipping purposes only or is it used when installed?

by chuck

• 10 years ago

1 answer

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I am mounting this booster in a 58 f100. The mounting bolts do not line up with the original holes. Do you make an adapter that the booster will blot to and then bolt to the original firewall mounting holes? Also which push rod should I use and do you have a tech bulletin to adjust the length of the push rod?

by Jack

• 10 years ago

1 answer

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Do you have a dual booster with 1" master cylinder that will direct bolt-on for a 1984 Toyota 4x4?

by 84Toy

• 11 years ago

1 answer

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Manual Drum Master Cylinder I have a '68 C10 with a 6 cylinder and four wheel manual drum brakes. Can I use this booster with my factory master cylinder? I would like to run power drum brakes on the truck; not looking to convert to front disks. The master cylinder on the truck currently has a 1" bore.

by rustyf1968

• 12 years ago

1 answer

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Where is the best place for connect is hoose on a 350 small block chevy ZZ4 with original manifold and cams and a 750 Holley carb. thanks a lot

by Philou

• 15 years ago

1 answer

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hello, how I can test my brake booster for know if it works well may be with a vacum pump?

by Philou

• 15 years ago

1 answer

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Was wondering if I can use this booter with four wheel disk. With a master cylinder that has a one and a eight inch bore.

• 15 years ago

1 answer

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