Hydraulic Clutch Slave Retrofit Kit
for
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.

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 Weight: 0.90 Price: $142.00 Buy: Includes the slave cylinder (7/8" bore) assembly, adjustable pushrod, fastening hardware 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: 0.90 Price: $142.00 Buy: 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.

• Choosing a larger slave for a smaller master may create a situation where the pedal pressure is reduce, 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.

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.

Incompatible Bellhousings

• Ford car and truck bellhousings that do not have the factory hydraulic slave cylinder mounting bracket as shown in the images

 

Hydraulic Lines & Fittings

Our slave cylinder uses a highly standard 1/4 DOT fitting. This is the female 3/8-24 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. Assembly, clutch line and flex hose, stainless and poly wrapped, 3/8-24 DOT 1/4 fittings Part #: HCR8 Weight: 1.30 Price: $87.38 Buy: For use with Novak and other hydraulic clutch master to slave applications with standard 3/8-24, DOT 1/4 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.

Hydraulic clutch release line adapter, late style, short (typ. TJ) Part #: HCA-1 Weight: 0.50 Price: $20.02 Buy: Hydraulic clutch release line adapter, early style, long (typ. YJ) Part #: HCA-2 Weight: 0.50 Price: $20.02 Buy:

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