The Aeroflow brake combination proportioning valve simplifies the brake proportioning adjustments on vehicles with custom brake systems. It allows an easier mounting position right next to the brake master cylinder with the use of the bracket (AF300-149 Sold Separately) as well as less hard-line plumbing. This combination block maintains full isolation between front and rear fluid circuits in the tandem master cylinders. The rear circuit has a single inlet and single outlet with the adjustable proportioning valve. The front circuit has a single inlet with two outlets. It can be run as a single outlet with one outlet plugged, or used to split the plumbing on its way to the front brake calipers. Each inlet and outlet port accepts 3/16” brake lines with 3/8-24” inverted flare females. A cool feature of this unit is the built-in brake light switch. This brake light switch allows you to activate your tail lights with hydraulic pressure from your brake system.
The Aeroflow brake combination proportioning valve simplifies the brake proportioning adjustments on vehicles with custom brake systems. It allows an easier mounting position right next to the brake master cylinder with the use of the bracket (AF300-149 Sold Separately) as well as less hard-line plumbing. This combination block maintains full isolation between front and rear fluid circuits in the tandem master cylinders. The rear circuit has a single inlet and single outlet with the adjustable proportioning valve. The front circuit has a single inlet with two outlets. It can be run as a single outlet with one outlet plugged, or used to split the plumbing on its way to the front brake calipers. Each inlet and outlet port accepts 3/16” brake lines with 3/8-24” inverted flare females. A cool feature of this unit is the built-in brake light switch. This brake light switch allows you to activate your tail lights with hydraulic pressure from your brake system.
AF300-148 Brake Adjustable Combination Proportioning Valve
The Aeroflow brake combination proportioning valve simplifies the brake proportioning adjustments on vehicles with custom brake systems. It allows an easier mounting position right next to the brake master cylinder with the use of the bracket (AF300-149 Sold Separately) as well as less hard-line plumbing. This combination block maintains full isolation between front and rear fluid circuits in the tandem master cylinders. The rear circuit has a single inlet and single outlet with the adjustable proportioning valve. The front circuit has a single inlet with two outlets. It can be run as a single outlet with one outlet plugged, or used to split the plumbing on its way to the front brake calipers. Each inlet and outlet port accepts 3/16” brake lines with 3/8-24” inverted flare females. A cool feature of this unit is the built-in brake light switch. This brake light switch allows you to activate your tail lights with hydraulic pressure from your brake system.
The Aeroflow brake combination proportioning valve simplifies the brake proportioning adjustments on vehicles with custom brake systems. It allows an easier mounting position right next to the brake master cylinder with the use of the bracket (AF300-149 Sold Separately) as well as less hard-line plumbing. This combination block maintains full isolation between front and rear fluid circuits in the tandem master cylinders. The rear circuit has a single inlet and single outlet with the adjustable proportioning valve. The front circuit has a single inlet with two outlets. It can be run as a single outlet with one outlet plugged, or used to split the plumbing on its way to the front brake calipers. Each inlet and outlet port accepts 3/16” brake lines with 3/8-24” inverted flare females. A cool feature of this unit is the built-in brake light switch. This brake light switch allows you to activate your tail lights with hydraulic pressure from your brake system.
in 19 offers
The lowest price for AF300-148 Brake Adjustable Combination Proportioning Valve right now is $129.34 at TrackTheory, compared across 16 retailers.
The all-time low was $79.73 on 13 Sept 2026 — today's price is 62% above the lowest ever. It has been notably cheaper before — worth setting a price alert.
Prices last updated 19 Oct 2026.
Last updated at 19/10/2026 22:10:21
Combo Proportioning Valve Adjustable Brake Valve
Aeroflow Brake Adjustable Combination Proportioning Valve Black
Delivery between Fri – Mon $8.80
Aeroflow AF300-148 Brake Adjustable Combination Proportioning Valve Black Brake Light Switch
Delivery between 20–30 Oct $10.95
Aeroflow AF300-148 Brake Adjustable Combination Proportioning Valve
Next-day delivery $19.99
AF300-148 BRAKE ADJUSTABLE COMBINATION PROPORTIONING VALVE
Delivery $25
COMBO PROPORTIONING VALVE
Delivery between 26–29 Oct $18
AF300-148 - COMBO PROPORTIONING VALVE
Free delivery
AF300-148 - COMBO PROPORTIONING VALVE
Free delivery
AF300-148 Aeroflow Combo Proportioning Valve Adjustable Brake Valve
Combo Proportioning Valve Adjustable Brake Valve | Performance Parts | Traction Auto Parts
Delivery between 23 Oct – 2 Nov $10.95
| Type | Valve |
| Vehicle Location | Rear (circuit), Front (circuit) |
| Application | Custom brake systems |
| Thread Size | 3/8-24" (inverted flare females) |
| Function | Simplifies brake proportioning adjustments, Activates tail lights with hydraulic pressure from brake system |
Combo Proportioning Valve Adjustable Brake Valve
Aeroflow Brake Adjustable Combination Proportioning Valve Black
Delivery between Fri – Mon $8.80
Aeroflow AF300-148 Brake Adjustable Combination Proportioning Valve Black Brake Light Switch
Delivery between 20–30 Oct $10.95
Aeroflow AF300-148 Brake Adjustable Combination Proportioning Valve
Next-day delivery $19.99
AF300-148 BRAKE ADJUSTABLE COMBINATION PROPORTIONING VALVE
Delivery $25
| Type | Valve |
| Vehicle Location | Rear (circuit), Front (circuit) |
| Application | Custom brake systems |
| Thread Size | 3/8-24" (inverted flare females) |
| Function | Simplifies brake proportioning adjustments, Activates tail lights with hydraulic pressure from brake system |
