Bill Smith
Founder, 1929-2014
Speedy Bill
Since 1952
Speedway Motors Logo
America's Oldest Speed Shop ®

Search

Adjustable Proportioning Blocks With Brake Light Switch

SAME DAY SHIPPING! Most orders ship within 24 hours.

Specs
Material Type:
Aluminum
Overall Height:
1.75
Overall Width:
1.00
Overall Length:
4.00
Sold in Quantity:
Each
Finish:
-
Outlet Fitting:
3/8"-24
Garage Sale:
No
Notes
Includes two adapter fittings (7/16"-24) and (5) 3/8"-24 brake line nuts.
Adjustable Proportioning Blocks With Brake Light Switch
Adjustable Proportioning Blocks With Brake Light Switch
Adjustable Proportioning Blocks With Brake Light Switch
Adjustable Proportioning Blocks With Brake Light Switch
Product Video
Adjustable Proportioning Blocks With Brake Light Switch

Click image to enlarge

Watch the video below to learn more about the differences in brake lines, flare types and fittings you may want to consider before plumbing away on your current chassis project.

Details

Reviews

Q & A

What's in the Box

This adjustable proportioning block allows you to run lines from the master cylinder to the block and then to the appropriate wheels. What is neat about it is that it also contains the proportioning valve and brake light switch. This dramatically reduces the amount of fittings needed and potential leaks.

The adjustable proportioning valve regulates rear brake pressure, helping to maintain correct brake bias between front and rear brakes. It is designed for dual bowl master cylinders. The distribution block connects to the master cylinder and distributes brake fluid to all four wheels. An easy to turn handle with directional arrows makes it simple to either increase or decrease rear brake pressure.

The block accepts 3/16" brake lines and the inlets and outlets on this unit are 3/8"-24 inverted flare females.  It has two inlets from the master cylinder, two outlets to the front brakes and one outlet to the rear brakes.  It includes five stainless steel 3/16" fittings and wiring pigtail for rear brake light switch. Mounts to any convenient location. This is not a direct factory replacement for original blocks. Some line modifications may be necessary.

910-31358 Instructions (PDF)

Learn more about how adjustable proportioning valves work by reading our tech article. Brake System Selection.  

Notes

  1. The brake block is plumbed as follows. The port on the proportioning valve end is the "out" line for the rear brakes. The port between th proportioning valve and brake light switch is the "in" line for the rear brakes. The port in front of the brake light switch is the "in" line for the front brakes. The port on the brake light switch end is the "out" line to the passenger front brake while the port on the bottom is the "out" line to the driver front brake.
  2. This block has individual lines for the front wheels and each line would require a residual valve if the master cylinder is mounted under the floor on the frame rail. 2 psi for each front if it has disc brakes and 10 psi for drum brakes. It still will require a residual valve to the rear with the same psi, depending on the brake type used.
  3. Brake System Builder's Tip (Link)

Customer Reviews

Rated 4.4 out of 5 by 15 reviewers.
RATING BREAKDOWN
15 reviews
5 Stars
12
4 Stars
0
3 Stars
1
2 Stars
1
1 Star
1
RECOMMEND THIS PRODUCT:

GOQUICK
Melbourne VIC, Australia
Product Rating

Excelent

March 07, 2015
Very good product save one T piece on front brake split too. Thanks
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

1949shoebox
Verified Purchaser
Tennessee
Product Rating

easily adjusted

October 13, 2014
Great for installation of brake system and eliminates some fittings since the valve has a port for the brake light switch,,,,
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

30scout
Verified Purchaser
Hingham, MA, USA
Product Rating

xlent

August 24, 2013
thanks, im using it on my thunderbolt. 68 427 side oiler with 2 4s, 4 speed with 3.89 gears. im using the adjustable proportion valve for my front and rear disc brakes
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

Angry Hot Rod Builder
Indiana
Product Rating

I'm color blind?

July 10, 2011
There I was,putting a hot rod together,wiring the brake lights. Line 3C states orange wire.Line C4 states white wire. In the picture and on the part,it's red and black. Some one is paying close attention to details.
Pros:
  • Easy To Install
No, I would not recommend this product.
Full Size Image

Was this review helpful? 0 0

partsman
Verified Purchaser
emmons kansas
Product Rating

quality product

June 18, 2012
work well on my 32 ford
Pros:
  • Easy To Install
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

FORDSRULE
Verified Purchaser
NW, WEST COAST
Product Rating

VERY NICE

February 24, 2011
THE SAME AS THE OTHERS BUT HALF THE PRICE
Pros:
  • Easy To Install
  • Lightweight
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

Wayne
Verified Purchaser
New Mexico
Product Rating

Works as it should

August 30, 2010
very good quality product that works as it should.
Pros:
  • Best price by far
  • High Quality Product
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

1965 F350
Fairfield Ca.
Product Rating

Excellent product!

March 14, 2010
Very easy hookup. Also mounts to stock GM proportioning valve bracket, an added plus for a clean installation.
Pros:
  • Great price
Yes, I recommend this product.
Full Size Image

Was this review helpful? 0 0

RACSAN Racing
Verified Purchaser
San Antonio
Product Rating

Cheap switch

August 23, 2011
Electrical tab broke off the pressure switch as soon as I got it out of the box. For a part this expensive it blows my mine there is not a threaded terminals for the pressure switch.
No, I would not recommend this product.
Full Size Image

Was this review helpful? 0 0

Rusted
Product Rating

fittings leaky and poor modulation

October 07, 2013
I would not recommend this product. I have now done several classic car brake jobs and the one using this has been the most difficult. Furthermore tightening the IN fittings is difficult due to location so you better get the flair perfect. Second the valve does not actually shut the flow off to the rear only slows it. I thought it might be more convenient and less hassle but no - far more difficult. The best value is to go with the little brass valve #91031357 for $35 and a brake switch and some fittings. I priced the total difference and found I would spend $15 more for this then for the individual components. The hassle is not worth it.
Pros:
  • one package
Cons:
  • limited modulation
  • difficult to access fittings
  • poor ergonomics/fitting arrangement
  • price - value
  • leaky fittings
No, I would not recommend this product.
Full Size Image

Was this review helpful? 0 0

Page 1 of 2
91031358

Product Q&A

8 questions : 11 answers

1 answers

can this valve be mountes upside down.. switch & adjustment knob pointed down?

fitzwell
June 07, 2014

can this valve be mountes upside down.. switch & adjustment knob pointed down?

Answers

June 09, 2014
EricM
Yes this can be mounted in any position.
2 answers

my front brakes are going to a tee to have one line go to the proportioning valve, can I block one hole on the valve to use just the one front line

bugg
leominster ma
May 04, 2014

my front brakes are going to a tee to have one line go to the proportioning valve, can I block one hole on the valve to use just the one front line

Answers

February 11, 2015
1949shoebox
yes
May 05, 2014
EricM
Yes you can plug one of the front outlet fittings and use a T for your front brakes if desired.
1 answers

Wiring Diagram Can you please tell me how to route the 2 wires on the pigtail that came with it? I assume one is for a dedicated 12v fused line in and the other is to the brake lights out? I misplaced the diagram.

bbl23T
January 24, 2014

Wiring Diagram Can you please tell me how to route the 2 wires on the pigtail that came with it? I assume one is for a dedicated 12v fused line in and the other is to the brake lights out? I misplaced the diagram.

Answers

January 27, 2014
EricM
Yes you will connect one wire to a fused 12v source and the other wire will power your brake lights. The full instruction sheet for this proportioning block can be found here: http://static.speedwaymotors.com/pdf/910-31358.pdf
1 answers

Do the two inlets feed a single reservoir? Do the two inlets feed a single reservoir that then feeds both the front and rear ports or are they separate circuits that feed the front and rear individually?

Ikeracing88
PA
July 23, 2013

Do the two inlets feed a single reservoir? Do the two inlets feed a single reservoir that then feeds both the front and rear ports or are they separate circuits that feed the front and rear individually?

Answers

July 23, 2013
Jason
The proportioning valve in the prop block will be used to adjust the rear brake pressure of the vehicle. The objective is to balance the pressure of the rear brakes to the front so that under hard braking, the rear brakes do not lock up before the fronts.
2 answers

I plumb from the master cylinder directly to this block, after the block, do I still add a 2 PSI residual valve to the front disc brakes and a 10 PSI to the rear drum brakes for my 32 roadster? The master cylinder is located beneath the floor.

Jason
Satsop, WA
October 31, 2011

I plumb from the master cylinder directly to this block, after the block, do I still add a 2 PSI residual valve to the front disc brakes and a 10 PSI to the rear drum brakes for my 32 roadster? The master cylinder is located beneath the floor.

Answers

October 08, 2013
Rusted
yes you need RPVs after.
November 01, 2011
John
Part # 91031358 There are a couple of ways to plumb in the proportioning block. One way is to go from the large reservoir on the master cylinder thru a 2 psi residual valve and to the in port for the front brakes. Then you can run two lines to the front brakes or plug one side and run one line forward and “T” further forward. The other reservoir goes to 10 psi residual and then out to the in port for the rear brakes and one line out of the block to the rear. In the other scenario if we run the residuals after the block and you run two lines to the front each line would require residual valves or you would need to plug one port and T after the residual valve. The rear still runs only one line in and one line out.
1 answers

will this valve work if mounted on its side.

October 18, 2011

will this valve work if mounted on its side.

Answers

October 21, 2011
John
Part # 91031358 This adjustable proportioning block can be mounted vertically or horizontally and is not mount specific. It will work with four wheel drum, disc/drum, or four wheel disc and offers adjustable metering of pressure to the rear brakes or in certain applications the front brakes. It also has a pressure sensitive brake light switch built in.
1 answers

will this work with four wheel drum brakes?

troy
franklin,tn
June 27, 2011

will this work with four wheel drum brakes?

Answers

June 28, 2011
Jason
Yes, this will work with disc, drum or a combination of each
2 answers

must you run two brake lines to the front ?

Carleton Michigan
March 16, 2011

must you run two brake lines to the front ?

Answers

October 08, 2013
Rusted
no - use a 3/8 16 IFM plug
March 23, 2011
Pat
You will need to have one(1) line to each wheel but you can split it up in the front of your car. Just run one line from the block and block off the other. Remember if you master cylinder is below your floor use residual valves 2 psi (disc) 10 psi (drums).
Page 1 of 1

You may also be interested in:

Wilwood 260-11179 Adjustable Proportioning Block
(Part #83526011179)
                        

This block has the proportioning valve built-in to the rear brake ports and a stop light switch built into the front brake ports. All ports are 3/8"-24 inverted flare female.

  • Compact design simplifies mounting, plumbing, & wiring
  • Maintains full isolation between front and rear fluid circuits
  • Rear circuit has a single inlet and single outlet with the adjustable proportioning valve
  • Front circuit has a single inlet with two outlets

Proportioning Valve Installation Instructions (PDF)

Brake System Builder's Tip (Link)

Detailed Schematic of Proportioning Block 

Learn more about how adjustable proportioning valves work by reading our tech article. Brake System Selection.   

Dual Outlet Master Cylinder Stainless Steel Dual Brake Line Kit
(Part #91031802)
                        

This is a pair of steel or stainless steel brake lines intended to simplify plumbing from the master cylinder to a proportioning block, such as our 910-31358 or 835-26011179.

  • Features tight 90° bends at the master cylinder end
  • Both ends of both lines are 3/8"-24 inverted flare nuts
  • The longer of the two lines measures app. 12" from the bend to the end
Dual Outlet Master Cylinder Steel Dual Brake Line Kit
(Part #91031801)
                        

This is a pair of steel or stainless steel brake lines intended to simplify plumbing from the master cylinder to a proportioning block, such as our 910-31358 or 835-26011179.

  • Features tight 90° bends at the master cylinder end
  • Both ends of both lines are 3/8"-24 inverted flare nuts
  • The longer of the two lines measures app. 12" from the bend to the end