Hydraulic Clutch Slave Retrofit Kit

for

Buick Bellhousings

Hydraulic clutch release systems have gained wide acceptance in the aftermarket as a keen solution to both engine conversion and stock clutch linkage replacement scenarios.

Novak's Hydraulic Clutch Slave Retrofit has evolved into its best rendition, as our #HCRB. This version bolts to Buick V6 & Buick V8 bellhousings, as found in many Jeep and GM applications.

Our #HCRB clutch kit has been engineered to bolt to most Buick 90 degree style bellhousings and to work with their associated pressure plates.

All included components work as a system to insure a straightforward installation. The arm provides the proper ratio for the great majority of pressure plates and the T6 hardened and hard anodized billet aluminum slave cylinder and piston are absolutely durable, yet rebuildable or replaceable down the road, if necessary.

3/4" Slave Version

• Our most popular diameter - if you are in doubt which to choose for your Jeep, start here
• e.g., Jeep CJ, XJ, YJ, TJ vehicles with factory 3/4" hydraulic master cylinders
• Other types of factory or custom vehicles
• Note that the Novak 3/4" slave is usually compatible with many 7/8" master cylinders, but will increase required pedal pressure and give a less precise feel

7/8" Slave Version

• e.g., Jeep CJ vehicles with factory hydraulic release though our usual recommendation is to use the 3/4" version for adequate throw. The 7/8" slave with stock CJ master cylinder will have to be adjusted and set up to exact minimum clearance specifications to function properly
• Other types of factory or custom vehicles

1971 Variant

1971 Jeep Buick bellhousings are a different animal. This was the year they tried a cable clutch release mechanism, and the bellhousing geometry is different than most earlier Jeep and other Buick bellhousings. The kit is the same but the bracket is longer to accomodate the difference.

Applications & Compatibility

Available Kit Versions

Hydraulic clutch release systems are typically engineered to have a 1:1 master-to-slave ratio, where the leverage is not obtained through differential hydraulics. The force is obtained through the leverage provided by the clutch pedal and then the release arm / fork at the throwout bearing, like a conventional mechanical clutch; the method of transmitting the force is the only difference. These principles are discussed here.

As such, the installer will generally choose between our 3/4" bore version or our 7/8" bore version to best match the diameter of their master cylinder.

• Choosing a larger slave for a smaller master may create a situation where the pedal pressure is reduced, but the lessened travel may not fully release a clutch.
• Choosing a smaller slave for a larger master may create a situation where there is excessive pedal pressure. However, the Novak 3/4" bore slave has more travel than OEM units and typically work with 7/8" master cylinders without blowing out. This is helpful if the throwout bearing needs more travel for release, but note that this is not a substitute for not choosing the right length throwout bearing.
• Keep in mind these ratios are based on the area of the bores, not the diameter so, πr² to calculate either master or slave area. Small changes in the bore size can yield a large change in distance or force. 3/4" bore yields .442 sq. in. whereas the 7/8" is .601 sq. in. Travel is a linear function of the area x the distance equals volume. The volume of fluid moved is the key and the same on either end no matter what changes are made so long as the system is sealed and no air is present.

For your best benefit, read and understand the principles of working with hydraulic clutch release systems and determine the applicability for your vehicle.

* Note that Full Size Jeeps (Wagoneer, Cherokee, J Truck) vehicles do not accommodate conventional, firewall mounted master cylinders due to the brake booster and the electrical bulkhead connector. If converting one of these Jeeps to hydraulic clutch release, the installer will need to custom configure a master cylinder accordingly.

Bellhousing Compatibilities

Many Buick, Olds and Pontiac Bellhousings work with this assembly, excepting those that feature a starter pocket on the driver's side, as this is the installation location of the #HCRB slave assembly.

If you are not sure of applicability, send us a digital picture or two of your bellhousing via e-mail, and we will let you know. See our contact page.

Aftermarket bellhousings such as Lakewood, McLeod and others have thus far proven compatible with this system.

Steering and Brake Clearances

The Buick V6 is found in many factory and conversion CJ Jeeps and Commandos. If your Jeep has the original factory Ross bellcrank steering, this kit may not have enough clearance. Please see the pictures of the HCR kit below as mounted to a bellhousing, and determine if it will fit into your Jeep.

Early Jeeps (1946-1971) that have had a proper Saginaw steering conversion should have enough clearance.

While most hydraulic clutch conversions in these Jeeps will happen in conjunction with a hanging pedal and brake cylinder conversion, be aware that if you are retaining your factory brake master cylinder on the frame, you may experience interference.

Shown below is the Chevy version of this kit. The Buick version is very similar in appearance and specs.

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