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Proportioning Valves or Disc Brake Valves - Proportioning valves are used in disc/drum brake systems to provide the correct pressure for front disc and rear drums. Four wheel disc valves are also available. The valves and distribution blocks available are listed below. 

Proportioning valves come in various shapes and sizes depending on the car you have and modifications to the braking system. 

The first year for disc brakes on GM and Chrysler products was 1967, Ford was 1966. All American cars built prior to this had four wheel drum brakes. Disc brakes were introduced as an option from 1967-1972. Starting in the 1973 model year, front disc brakes were primarily standard and front drums were rarely available. The dual master cylinder that separates the front and rear braking systems was introduced and standard on all cars in 1967. Therefore, all 1967 and newer cars came with dual master cylinders from the factory. Disc brakes require over three times the line pressure of drums, so the master was divided to provide pressure to the front and rear separately. This also meant that if a front line blew out the car would still have pressure to the rear brakes and vice versa.

All 1967-68 GM factory disc brake cars came with dual piston calipers. If the car is a 1969 or newer car, it came with single piston calipers. All aftermarket conversions come with the single piston calipers, but they are not factory correct for the 1967-68 cars. The single piston conversion will bolt on 1964-72 GM A-Bodies, 1967-69 F-Bodies and 1968-74 X-Bodies and function perfectly.

Since disc brakes were new in 1967, the valve was still being worked out for the next few years. The 1967-70 valves could consist of as many as three elements and the valves would not work properly without all the pieces. Both 1967-70 factory drum and factory disc cars have (or had) a distribution block which is identical whether the car was drum or disc. Although very similar in appearance to a proportioning valve, the distribution block does not alter brake line pressure. The distribution block keeps front and rear systems separate, splits the left and right front lines and houses the sending unit for the brake failure warning light. The 1967-1970 factory disc vehicles employed an additional valve, referred to as a hold-off valve, mounted at the master cylinder. The final component in the 1967-70 factory disc brake systems was a correction valve typically located in the front to rear brake line for the rear brakes. This valve was not used in every factory disc brake car, but would make the front to rear line two pieces with the valve usually found mounted near the floor pan of the car. An original 1967-70 disc car can be factory correct without the correction valve, but not without the hold-off valve at the master cylinder.

In 1971 for GM and 1972 for Chrysler, the one piece combination valve replaced the multiple piece design. The combination valve keeps front and rear systems separate, splits the left and right front lines, houses the sending unit for the brake failure warning light and provides the proper brake line pressure for the front disc and rear drum systems. This is why it is important to know what is correct for your car and how your car can (or will) be converted from drum to disc. There are three basic disc conversions for 1967-70 cars: 1) Factory original conversion, 2) Combination valve conversion and 3) Adjustable valve conversion. Each conversion has its benefits. The staff at Inline Tube will help you determine the best disc conversion configuration for your vehicle. Valves, distribution blocks and dual master conversions are illustrated and listed below.

Mopar Prop Valves / Distribution Blocks - Inline Tube Exclusive

Details:
Now available for the first time, all the hard to find disc / drum Mopar valves that connect your lines. Inline Tube has manufactured an impressive list of valves and blocks for all popular applications. No longer will you have to deal with rusted, stripped out brake components. These new valves feature correct size and shape castings, gold silver and zinc brackets, and all the features that make a concourse part. Inline Tube is dedicated to manufacturing what you need so your car can be the very best.

All valves listed at bottom of page in MOPAR section.

Distribution Blocks - Inline Tube Exclusive

1967-69 GM F-Body Camaro / Firebird 
1968-72 GM X-Body Nova / Ventura
1967-70 Chevy / GMC Truck

Details:
Now available: 1967-69 GM F-Body Camaro/Firebird distribution block. This block was used on all cars, either disc or drum. The block is bolted below the master cylinder and is not a proportioning valve as it does not modulate line pressure. If there is a loss of pressure in either the front or rear braking systems, it will activate the brake warning light in the dash. From 1967-74 this block was used on all drum cars and with the round hold-off valve at the master on 1967-70 disc brake cars. In 1971, disc brake cars used a different one piece valve and the drum brake applications continue to use the distribution block. Since this block provides equal pressure to the front and rear brakes it is also great for 4 wheel disc applications.

Also available are the 1967 and 1968-70 Chevy/GMC truck valves. All trucks came from the factory with drum brakes until 1970. The only brake-related option available was power assist. In 1971 all trucks went to disc brakes. All 1970 and older original trucks had drum brakes and all 1971 and newer trucks had disc brakes.

These valves are exact reproductions featuring a cast black body, the correct mounting bracket and fully functional internals. You will also find with our current manufacturing procedures the reproduction has no tool stamping marks and the edges of the part are cleaner than the original.

1967-72 GM A-Body Distribution Blocks - Inline Tube Exclusive

Details:
Now available 1967, 1968-69, 1970-72 GM A-Body (Chevelle / GTO / Cutlass / Skylark) distribution blocks: This block was used on all cars, either disc or drum, and is located down on the frame below the master cylinder. This is not a proportioning valve because it does not modulate pressure. If there is a loss of pressure in either the front or rear braking systems, it will activate the brake warning light in the dash. From 1968-72 this block was used on all drum brake cars and with the round hold off valve at the master on disc brake cars from 1967-70. In 1971, disc brake cars used a one piece proportioning valve and the drum brake applications continued to use the distribution block. This block provides equal pressure to the front and rear brakes so it is also great for 4 wheel disc applications. 1968-69 and 1970-72 are very similar blocks except the fitting sizes change for the different production years. This item is an exact reproduction featuring a brass body, the correct bracket, phosphate plating and fully functional internals. You will also find with our current manufacturing procedures, the reproduction has no tool stamping marks and the edges of the part are cleaner than the original.

1971-77 GM Prop Valve - Inline Tube Exclusive

Applications:
71-77 A-body Chevelle / El Camino
71-77 F-body Camaro / Firebird
71-77 X-body Nova
71-77 Pontiac LeMans / GTO
71-77 Olds Cutlass / 442
71-77 Buick Skylark

Details:
Finally the correct 71-77 GM Prop. Valve. For years other companies have been selling and reproducing the 78 and newer valve with the plastic incorrect wire lead designed for the 78 and newer GM cars. This valve is exact to the factory original so your stock wiring lead will hook right up with out having to cut and splice any wiring. We have heard all the installation problems with the wrong lead wire and for years we also sold the other lead wire ($8.00) that would have to be spliced in so your $85.00 valve just turned into a $93.00 valve and more work to install it. Now it is correct - so all the install problems will be eliminated. This is an Inline Tube exclusive and available only Here!
This is a concourse level Inline Tube reproduction it comes complete with the brass valve and features the correct wiring lead. It is made to NOS specifications with all the details so it is identical to the factory original.

1967-70 Disc Brake Hold-Off Valve - Inline Tube Exclusive

Details:
This item is an exact reproduction disc brake correction valve. This valve was used to hold off pressure to the rear brakes so the front brakes would go on a split second before the rears. This was also considered a correction valve for several model years. During extreme braking conditions, this valve prevented the rear of the car from washing out sideways and evened out braking loads. Inline Tube has reproduced this valve for every application. This item is an exact reproduction featuring a brass body, the correct bracket, phosphate plating and functioning internals. The reproduction has no tool stamping marks and the edges of the part are cleaner than the original. When you expect the best, Inline Tube is your first choice.

1967-70 GM Hold-Off Valve 

Details:
This is the hold-off valve that mounts on the stud of the master cylinder on all factory 1967-70 disc brake cars. It is used in conjunction with the distribution block mounted on the frame, which is the same on factory disc and drum cars. This valve holds off the front brakes to give time for the rears to activate. At a calibrated pressure, the valve allows fluid to pass and engages the front brakes. This valve is the same on all GM cars, but the bracket is different for applications NOT listed below.

     

Now Available, Chrome Parts:

Chrome Valves

                       
       
                     PR120                                            PR121

New 1964-67 GM A-Body Chevelle Distribution Blocks 

Another Exclusive Inline Tube Product

New 1965-66 GM B-Body Impala Distribution Blocks 

New 1966 GM B-Body Pontiac Distribution Blocks

New GM Corvette Distribution Blocks 

Details:
Inline Tube is proud to introduce factory correct brake blocks. These are exact reproductions of the originals, down to every detail. They are the correct size, shape and thickness. The block mounts to the frame and the single master cylinder line screws into the top while the left and right front screws to the sides and the front to rear screws into the back. These blocks are often discarded, missing or stripped. One tee is used per car. If you are a dealer looking for quantity pricing call Inline Tube sales: (586) 532-1338.

New GM Blocks and Lines for Converting to Dual Master

Details:
Inline Tube has introduced dual master conversion blocks and we now offer the entire assembly that includes the master to block lines. To switch to a dual master cylinder, mount the brass block on the frame and install your master cylinder lines. Our conversion will work with the original left and right front and front to rear lines. This kit completes what you need to upgrade safety to your classic. It separates the front brakes from the rear so that losing a brake line does not cripple the entire system. This conversion is made to look as original as possible and blend in with the factory components. If you are a dealer looking for quantity pricing, call Inline Tube sales: (586) 532-1338.

Brake Light Lead Wire

Details:
This is the connector and lead wire that is located at the top of the proportioning valve. If your vehicle does not have the matching connector this lead wire plugs directly into the valve and is wired into the warning light wiring harness. 

Factory Prop Valve Brackets

Details:
Inline Tube has made factory correct proportioning valve brackets so you can mount your valve in the factory correct location. You will also find with our current manufacturing procedures, the reproduction has no tool stamping marks and the edges of the part are cleaner than the original with superior finish coatings. When you expect the very best, Inline Tube is your only choice.

Disc Brake Conversion Valves & Lines

Details:
Inline Tube has made all the factory correct proportioning valves, lines and brackets so that these components will route and mount correctly. You will also find that our reproductions have no tool stamping marks and the edges of the part are cleaner than the original with superior finish coatings. When you expect the very best, Inline Tube is your first choice.

Application List
Buick

Cadillac

Chevrolet

Chevrolet Truck

Oldsmobile

Pontiac

GM Valve Notes:
1966 and earlier cars originally had a single master cylinder with drum brakes. There was no proportional valve or disc brakes available prior to 1967 from the factory. The tee block that mounted to the frame served as the distribution block. When converting to disc brakes the system will need a proportioning valve. There are two basic disc conversions for 1966 and earlier cars: 1) Combination valve conversion and 2) Adjustable valve conversion. Each conversion has its benefits. The staff at Inline Tube will help you determine the best disc conversion configuration for your vehicle.

1967 was the first year for disc brakes for GM and Chrysler and 1966 for Ford. 1967 cars all had a dual master cylinder. If the car had drum brakes, there was a distribution block with a built-in brake warning switch. If the car had factory disc brakes, it used the drum distribution block in conjunction with a disc brake hold-off valve, which made the disc cars a 2 part valve. With some vehicles, a third component, a correction valve, was also part of the system. There are three basic disc conversions for 1967-70 cars: 1) Factory original conversion, 2) Combination valve conversion and 3) Adjustable valve conversion. Each conversion has its benefits. For disc brake conversions, replacement aftermarket one piece valves are available. See the listing above. This valve will NOT plumb into existing factory lines. The staff at Inline Tube will help you determine the best disc conversion for your vehicle.

If converting any of the above disc/drum cars into 4 wheel disc, Inline Tube offers a disc/disc valve that is identical to the disc/drum valve. This valve is metered for 4 wheel disc pressures and is $99.00. This valve can save considerable time and expense and can allow use of existing brake lines and routing. Proportioning valve brackets are also available for cars and trucks with disc conversions for $18.00.

Mopar - Jeep (New Mopar Valves in stock)

Ford Truck

Street Rod

Street Rod Valve Notes:
The adjustable valve is designed for both street rods and conversions using factory front brake lines. Of all the disc brake conversion configurations, using the adjustable proportional line valve is typically the easiest proportioning solution because it is installed anywhere in the rear lines between the master and the rear hose and controls only the pressure to the back brakes. No line pattern changes are necessary for installation. The front brakes get full pressure and the rears are turned down until they do not lock up and provide a smooth stop. Adjustment depends on tire, caliper and rotor size and is different for all cars. Adjustable valves can also be used on factory or race cars to fine tune the rear brakes or because of mismatched components.

Residual Valves:
These valves are used in brake systems where the master cylinder is mounted lower than the calipers, typically under the floor. This is a check valve that keeps either 2lb (disc) or 10lb (drum) of pressure in the system to prevent the fluid from running back and overflowing the master cylinder. These valves should be mounted as close as possible to the master before the proportioning valve. These valves are not needed on firewall mounted master cylinders. 

Quick Tip - Prop Valves

Inline Tube is the only company that offers the factory original valves for you classic car.