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Hydraulic Clutch Slave Retrofit Kit
Ford Hydraulic Style 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 third and best rendition, as our #HCRF. It bolts to the popular Ford hydraulic style bellhousings - typically Small Block V8 and Big Block V8 engines.

Ford Hydraulic Clutch Release Kit

Option I - 7/8" bore

  • e.g., Ford vehicles with 7/8" to 1" factory hydraulic master cylinders
  • Other types of factory or custom vehicles
Kit HCRF-78, hydraulic clutch retrofit slave cylinder, Ford version, 7/8" bore
Part #: HCRF-78* Item in Production
Weight: 0.90
Price: $142.00
Includes the slave cylinder (7/8" bore) assembly, adjustable pushrod, fastening hardware
* We're currently working on restocking this part. Please call us at 435-753-2513 for product lead time.

OOption II - 3/4" bore (our most popular size)

  • e.g., Jeep CJ, FSJ, 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
Kit HCRF-34, hydraulic clutch retrofit slave cylinder, Ford version, 3/4" bore
Part #: HCRF-34
Weight: 2.00
Price: $142.00
Includes the slave cylinder (3/4" bore) assembly, adjustable pushrod, fastening hardware

The Kit
Our #HCRF slave cylinder kit has been engineered to attach to ~1981-1991 Ford hydraulic V8 bellhousing brackets as and to work with their associated pressure plates.

The installer will use their factory Ford release arm and throwout bearing as indicated for use with your application.

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.

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.

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 accomodate 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.

Why do we provide a hydraulic slave cylinder for an application that already featured one?

  • Bore size: the factory Ford slave cylinders are typically oversized for many Jeep, car and truck applications, and therefore do not provide enough travel to release the clutch disc
  • Hydraulic fittings: the factory Ford fittings are uncommon and problematic to connect to. Our standardized fittings make conversion work much easier
  • External size: in tighter spaces, the envelope taken up by the factory Ford cylinder is just too much, considering frame, exhaust, steering and header clearances
  • Composition: the plastic Ford slave cylinders are hardly reknown for their longevity. Our hardened billet aluminum cylinder and piston will give longer and more durable service


Bellhousing Compatibilities
The Novak #HCRF has been proven to work on big clutch & small clutch as well as big bore and small bore Ford bellhousings. Your bellhousing *must* have the factory hydraulic slave cylinder mounting bracket, as found with most ~1981-1991 Ford trucks.

External hydraulic cylinder assembly

Incompatible Bellhousings

Ford hydraulic slave cylinder


Hydraulic Lines & Fittings

Our slave cylinder uses a highly standard 1/4 DOT fitting. This is the female 7/16-24 threaded fitting ready for an SAE, male double-flare fitting. Most installers that have done any work with brake lines will be very familar with these, as will their local parts supplier.

For the easiest installation and the most professional look, we recommend our braided stainless steel and poly wrapped flex hose and line assembly (right). It features a flareless compression coupling that can accept the provided straight, 90 degree or 180 degree pre-bent lines. Or the installer can bend the provided straight line to best match their situation.

This line is ~3' in length.

Hydraulic line & hose assembly

Assembly, clutch line and flex hose, stainless and poly wrapped, 7/16-24 DOT 1/4 fittings
Part #: HCR8
Weight: 1.30
Price: $89.60
For use with Novak and other hydraulic clutch master to slave applications with standard 7/16-24, DOT 1/4 fittings
Hydraulic Slave Fittings


Optional Hydraulic Line Adapters for Jeeps
These useful adapter fittings (left) permit the adaptation of our #HCR to 1991-present Jeep master cylinders that use the o-ring style fittings.

Master cylinder fitting

Hydraulic clutch release line adapter, late style, short (typ. TJ)
Part #: HCA-1
Weight: 0.50
Price: $20.02

Master cylinder fitting

Hydraulic clutch release line adapter, early style, long (typ. YJ)
Part #: HCA-2
Weight: 0.50
Price: $20.02

These fittings each feature a male 1/4" DOT threaded ends so that the installer can use or make standard hydraulic lines or hoses for the particular situation. The tip inserts into your 1991-1995 Jeep YJ (and 1991-1996 Jeep XJ) or 1997-present Jeep TJ & XJ master cylinder using the factory style o-ring and retaining pin. We recommend that you verify your particular fitting with the image and descriptions below prior to ordering.

Note that 1980-1986 CJ's and 1987-1990 YJ's master & slave cylinders already feature a female DOT fitting and do not require these adapter fittings.

A common example of hydraulic hose / line use of these adapters when installing the #HCR kit is to buy or fabricate a line with a female DOT 1/4 fitting for the adapter/master side of the circuit. This line should then feature a male DOT 1/4 end for the slave side of the #HCR cylinder port.


Optional Rebuild Kits
HCR series rebuild kit

Kit HCRK-34, rebuild for Novak 3/4" hydraulic slave cylinders
Part #: HCRK-34
Weight: 0.16
Price: $23.90
Contains the boot, piston, u-cup seal and compression spring
Kit HCRK-78, rebuild for Novak 7/8" hydraulic slave cylinders
Part #: HCRK-78
Weight: 0.16
Price: $23.90
Contains the boot, piston, u-cup seal and compression spring