Custom Master Cylinder, Pedal Box and Hydraulics

Master Cylinders/Pedal Box

We had been using the original tandem master cylinder originally designed for the bugeye; however, it was a master cylinder sourced from Gerard Chateauvieux of Gerard’s Garage that was modified to incorporate 3/4″ bore pistons for the brakes and the clutch.

Twin Chamber 3/4″ Master Cylinder

Sebring Sprites used a custom pedal box with two offset Girling master cylinders with their own fluid reservoirs. We purchased a replica of the Sebring Pedal Box from Brookfab in the U.K.

We were quite pleased with the Brookfab assembly including the master cylinders, push rods and springs – very professional job.

Brookfab Pedal Box with Girling Master Cylinders

Brookfab Pedal Box

Brake Pipes and Hoses

All new cunifer copper alloy brake pipes with stainless fittings were formed and installed on the car for the 2024 restoration. In addition, Goodridge Stainless Braided (black) were also installed on the car. Both can be seen in the image below:

Cunifer Brake Pipes and New Fittings

Cunifer Brake Pipes and Goodridge Hoses

Brake Fluid

We have decided that because all of the brake system and clutch system are totally new we will use Dot 5 silicone brake fluid in the Bugeye.

Front Disc Brake Conversion

We bought the Bugeye in 1998 and shortly thereafter the car was taken to Grand Touring Classics, Inc in Stanarsville, VA for a safety inspection and a conversion to front disc brakes. Garland Gentry and his assistant took care of collecting the needed parts from a post 1964 Midget and installing them on the car. After some period of time we changed out the 7/8″ master cylinder for a 3/4″ which worked much better.

Of course, it is not as simple as just switching out the brakes. it is also necessary to install new stub axles and king pins, dust tubes and springs, hubs, back plates, calipers, hose brackets, rotors, pads with pad retaining plates with clips, new hoses with banjo bolts and copper washers. For the complete restoration of the car in 2024 all of the front brake components were updated and/or replaced. Parts were sourced from A.H. Spares and Moss Motors.

The front brakes, steering and suspension are integrated in assembly. Details of all of these  mechanicals are detailed in other posts regarding these subjects. The build up of the front hub assemblies and brakes ,may be found in this post:   A video showing the assembly is included in the post.

Front Suspension, Brakes and Steering Completed

It has been a little more than three months since we began the work on the front suspension, brakes and steering in the Bugeye, but we have now completed the rebuild and have the car back on its tires and on the ground!

Everything has been updated and documented in previous posts in this blog:

New hub bearings and seals

New king pins and bushings in the spindle axles

New rotors, calipers and brake pads, new Goodridge stainless brake hoses, new cunifer hard brake pipes, new “Sebring-type” pedal box and pedal pads with separate master cylinders

New “A” arms, fulcrum pins and poly bushes throughout

New steering rack, shims and rod ends and the proper steering arms were sourced and installed

Rebuilt lever shocks and new rubber bump stops

New coil springs

Everything cleaned and painted

The Bugeye Restoration Episode Thirty-five video shows the final steps in completing the work described above.

The following steps are addressed in the video:

0:00 – Torquing the hub nuts and installing split pins

0:44 – Hub grease caps installed

0:48 – Front caliper banjo bolts installed

1:20 – Goodridge Stainless Steel flexible brake hoses installed

1:35 – Making brake pipe bubble flares

4:42 – Master cylinder to brake union brake pipe installed

5:00 – Steering rack installed

5:52 – Steering rack bracket shims installed

6:14 – Steering column to steering rack pinion shaft mating

6:50 – Steering rack mounting clamp bolts torqued

7:17 – Tie rod ends fitted and torqued

7:30 – Toe-in adjustment

7:50 – Front tires mounted and car placed back on the ground

9:12 – Inner fulcrum pins tightened





The front drum brakes of the 100-Sixes were replaced by Girling 11” disc brakes on the 3000 in March 1959. Rear brakes were 11” Girling drums that were also controlled by a handbrake lever located on the right side of the gearbox tunnel

 Brake Modifications

The most significant modification I made to the braking of the 1960 MKI was the conversion of the rear drum brakes to disc brakes. This was accomplished with a kit based on Jaguar calipers coupled with mini-handbrake calipers sourced from Cape International. New rods to connect to the balance lever are supplied so that the handbrake functions as original. This is a pdf file of the instructions provided by Cape International.Cape Int Disc Brake Conversion 1

Rear Disc Brake

Rear Disc Brake

Handbrake Lever

Handbrake Lever

Aeroquip Braided Stainless Steel Hoses

Original-style rubber brakes hoses were replaced with stainless braided hoses also sourced from Cape International.

Stainless & Braided Brake Lines

Stainless & Braided Brake Lines

Drilled Front Brake Rotors

While standard rebuilt calipers were used in the front, the rotors were replaced with drilled rotors supplied by Cape International.

Drilled Front Rotors

Drilled Front Rotors

Speed Bleeders

I utilized the new technology for brake bleeders, Speed Bleeders. These bleeders have a small stainless ball in them that close off the release of brake fluid, making the process of brake bleeding much easier.

Speed Bleeders

Speed Bleeders

Recent production of the hydraulic brake switch has not produced a reliable switch. A remedy to the situation is to use a mechanical brake switch first developed by hot rodders. I sourced the switch I used from Watson’s Street Works. A description is provided in this Watsons mechanical brake switch.

Watson's Brake Switch

Watson’s Brake Switch

Watson's Brake Switch

Watson’s Brake Switch

 Brake Reservoir Canister Gasket

Other Healey restorers had noted that if overfilled, hydraulic fluid could slosh out of the vent hole in the reservoir cap and ruin the paint. Ever resourceful contributors to the British Car Forum discovered that a simple little gasket available in most auto parts stores fit perfectly in the reservoir cap, thereby solving the problem. I used one of the se “HELP” gaskets, #42072 in the Bloody Beast.

HELP Gasket

HELP Gasket


Brakes MK2

The Front and Rear Brakes

The Jaguar MK2 uses a single line hydraulic system actuating disc brakes in both the front and rear of the car. While the four wheel disc brakes were “cutting edge” at the time of production for a four-door sedan, today, the braking action can be upgraded with vendor supplied modification kits. Front Brake Upgrade I decided to go with the Coopercraftbrake upgrade kit for the front and rear of the car. Up front, their four pot brake caliper range has been updated to include stainless steel pistons, a refined and improved caliper design for strength and efficiency. To gain some weight savings I installed the optional aluminum calipers. The system employs ventilated disc rotors that should help with cooling. No modifications were required for mounting. Every thing was a “bolt-on” application. Coopercraft provided fitting instructions with their kit:

Coopercraft Front Braking Installation Instructions

Coopercraft Front Braking Installation Instructions

Calipers and Pads

Calipers and Pads

Coopercraft Calipers

Coopercraft Calipers

The photos above show the upgraded EBC “Green Stuff” brake pads. After installing the vented rotors on the front suspension crossmember assembly I installed the calipers finding that it appeared that no shims would be needed for proper fit.  Two bolts secure each caliper to the stub axle housing lugs: The shorter 1/2″ x 1 1/8″ – 20 is at the upper mount and the longer 1/2″ x 2 5/8″ – 20 is at the lower mount. Each bolt is accompanied by a flat washer and a split washer. The cad plated brackets were used on the original brakes to support the union of the rubber brake hose to the metal caliper pipe. With the Coopercraft upgrade these are not used, as the hose links directly to the caliper.

However, I found that sliding the EBC pads into the caliper, on either side of the rotor, was difficult and the concluding fit was much tighter than I liked. After checking with Coopercraft, they advised that the EBC pads are about 2mm wider than the standard pads. I volunteered that while I was looking for an “upgraded” braking experience, I was not going to be racing the car. They suggested that I might want to go with standard pads rather than the EBC pads. They also recommended that if I was going with standard pads in the front brakes that I should do the same with the rear brakes. Oh well, just wasted money once again!

I ordered standard front pads to fit a Series II/III E-Type (the proper pad to fit the upgraded alloy calipers) JLM 9515 as well as standard pads for the rear 10821* from SNG Barratt and they fit just as they should. Wish that I had ordered the Mintex pads to begin with!

Coopercraft Vented Rotors, Alloy Calipers fitted with Goodridge Stainless Brake Hose and Hubs installed

Coopercraft Vented Rotors and Alloy Calipers with Standard Mintex Pads and Hubs Installed

Anti-rattle clips are added after the pads and pins are installed. These spring clips are part number 12292 and a total of four are required.

Anti-Rattle Spring Clips for Brake Pads Installed

Mintex Front Caliper Brake Pads


I replaced the original rubber brake hose with Goodridge stainless hoses. The larger fitting on the end of the hose is metric, 16 mm diameter – .50 with with a 16mm -.50 nut.

Goodridge Stainless Brake Hose

Goodridge Stainless Brake Hose

After mounting the calipers I safety wired the caliper mounting bolts. 

Stainless Safety Wire and Twist Tool

I used 19 gauge wire that is probably a little heavier than needed but it worked just fine. If you are doing safety wiring, it can certainly be done with regular pliers, but the twist tool gives a very nice uniform appearance to the wire and is easy to use. 

Safety Wire on Front Brake Calipers

No videos are perfect, but this short video gives you a pretty good look at how safety wiring should be done. There is sound but screen captions are used initially.

Rear Brake Upgrade

In the rear, the Coopercraft upgrade kit consists of four redesigned and uprated cylinders, incorporating stainless steel pistons in an alloy caliper. This kit utilizes the standard handbrake mechanism and is designed to maintain a good balance with their uprated front sets. As stated previously, I did not use the EBC pads and instead substituted the standard pad provided by SNG Barratt.

Alloy Rear Brakes

Alloy Rear Brakes

Rear Brake Friction Pads

The small tabs with holes in each brake pad is to permit the insertion of a hooked wire to pull the pad out when it is replaced. The pads are held in place by the Retaining Plate for Friction Pads as seen below with mounting hardware.

Rear Brake Friction Pad Retainer with Fasteners

The image below shows the Coopercraft Alloy Pistons and Housings installed in the original calipers with new pads secured by the pad retainer. 

RH Rear Brake Caliper with Retaining Plate for Friction Pads Installed

The calipers need to be centered around the rotors and this is accomplished with the use of shims on the two bolts securing the calipers to the axle. On my car, I use five .010″ shims on the upper bolt of the RH caliper and five .010″ shims on the lower bolt. On the LH side, I used no shims on the upper bolt and two .010″ shims on the lower bolt.

Following assembly, I safety wired the mounting bolts for both rear calipers.

Safety Wired Rear Calipers

A warranty is also provided by Coopercraft:

Coopercraft Brake System Warranty and Liability

Coopercraft Brake System Warranty and Liability

Rear Brake Caliper Rebuild

Rear Brakes

Rear Brakes

In addition to adding the new Coopercraft Piston/Cylinder Sub-Assemblies I completely rebuilt the Rear Caliper Assemblies including the Handbrake Calipers. As the image below illustrates the original silver color was long gone!

Left Rear Brake Caliper

Left Rear Brake Caliper

To disassemble the calipers, I first separated the handbrake calipers from the primary caliper. To do so, I bent back the tabs on the Tab Washer and unscrewed the two Bolts, Securing Handbrake Mechanism to Rear Calipers. I then removed the Retraction Plate Fork that permitted the removal of the LH and RH Handbrake Pad Carrier Assembly with the friction pads. The Bolt, Securing Pad Carriers to Operating Lever was then unscrewed separating the two Carriers. I then removed the Support Plates for friction pads which simply fit into slots on the caliper body. Four 1/4″-24 x 7/8″ hex head bolts with shakeproof washers secured each Piston/Cylinder Assemblies. These were removed and the assemblies with the friction pads were removed. The Retaining Plate for friction pads was held in place with a 1/4″ – 24 x 7/8″ hex head bolt. It was removed and will not be replaced until the caliper is mounted and the new friction pads are installed. The Bridge Pipe Assembly and the Bleed Screw and Ball Assembly were removed from the Piston/Cylinder Assemblies and replaced with a new pipe and fittings. All components were then media blasted or otherwise cleaned and painted with Eastwood’s silver ceramic caliper paint. New bolts and screws were installed along with new friction pads.

LH Rear Brake Caliper Components

LH Rear Brake Caliper Components

Right Rear Brake Caliper Refurbished

Right Rear Brake Caliper Refurbished

Right Rear Brake Caliper Refurbished

Right Rear Brake Caliper Refurbished

Rear Caliper LH & RH

Rear Caliper LH & RH




A New (And Proper) Master Cylinder

Although I had converted the front drum brakes to disc brakes not long after purchasing the Bugeye, I had not been able to find the proper 3/4” piston version that would have been used on the 1098 cars. My dad was able to source one from California during the previous winter, and in early August he installed it. He ordered the new master cylinder from Gerard Chateauvieux at Gerard’s Garage Both the clutch and the brake master bores are 3/4″. The push rods are also shorter than the originals. More information is available from theses two pdf files:

Disc Brake Upgrade– Midget Sprite Spridget Master Cylinders Disc Brake Upgrade

After bleeding the brakes and clutch we did end up with improved brake pedal feel and stopping power. He removed the entire pedal box, installed the new master and then re-installed the pedal box.

Master Cylinder

Master Cylinder

Bugeye Brakes Improvement

We have never been very happy with the brakes on the Bugeye. We installed front disc brakes but the pedal travel was way too much and the master cylinder always seemed to leak slightly. We were going to replace the master cylinder with the correct one for the 1098 car, but others suggested that the original 948 MC would work fine if everything else was working properly. Having the rear brakes adjusted properly and using aeroquip stainless steel brake lines were the primary suggestions for brake improvement.

We installed the stainless brake lines, and fitted new green stuff disc brake pads in the front, with new shims also. Purchased and installed new copper alloy brake lines throughout the car. Paul Asgeirsson was a big help on the proper process for adjusting the rear brakes.

Put the springs on the brake shoes from the back plate side BEFORE putting in the adjuster. Lots easier.

To put in the adjusters with the springs in place, just pry down the bottom shoe away from the wheel cylinder with a screwdriver.

Disconnect the parking brake cable from the cylinder brake arm.

Put the drum on over the shoes and put on the 2 drum holding screws.  These originally are pozi-drive screws and the phillips head screwdriver just chews them up.  Get some new ones that are phillips head.  They are 1/4 X 28 X 3/4″  flat head machine screws.  Readily available.

Now adjust the brakes up as tight as you can.  Press on the brake pedal pretty hard to seat the shoes.  Check the shoe adjustment by rotating the drum if you can.  If you can tighten up the adjuster nice and snug and back off one click.  Do both sides this way.  Should be able to rotate the drum OK, but typically not freely.

Hook up the parking brake clevis.  If it’s too short, loosen the adjuster inside the car.  5/8″ deep socket and hold the cable with a 1/4″ wrench on the flat spot.  Loosen until you can hook up the clevis.  Do both sides this way.

Now you need to final adjust the parking brake.  Take up the slack on both cables until they are just beginning to affect the rear brakes.  Make both cables equal tension.  Easy to check when you pull on the handle like you are parking the car.

Now the parking brake handle should only go up about 15 to 20 degrees.  Now this is important.  Never change the adjustment inside the car again until you reline the rear brakes again.

As the brakes wear, the handle will come up to maybe 45 degrees or so. That’s a signal to readjust the rear brakes.  When you do that, the park brake handle will only pull up 15 or 20 degrees again.

Paul also provided some brake adjusters for the rear drums that were in good shape and we used those. New brake shoes were also installed. Speed bleeders were used on the front calipers and the rear wheel cylinders. While working on the rear axle it seemed that the time was right to add new seals and gaskets.

The old pedal box was a mess from leaky brake fluid so the box was pulled, cleaned up and powder coated for a more permanent finish. New gaskets were added to the master cylinder along with new push rods, clevis pins and etc. Also added new aluminum racing pedals to the brake and clutch pedals.

Finally, the system was bled and all the hard work was worthwhile!! Improved brake pedal and now we eagerly await actually putting the car on the road.

Powder Coated Drums

Powder Coated Drums

Ugly Pedal Box

Ugly Pedal Box

Powder Coated Box

Powder Coated Box

Pedal Box Restored

Pedal Box Restored

Safety Check & Rivergate Modifications

The week after we got the Bugeye home, Dad took it over the mountain from Harrisonburg to Grand Touring Classics in Stanardsville, VA. An unlikely place for a British car shop, but they seemed to know Healeys and were in the process of restoring a Bugeye. Garland Gentry ran the shop and was willing to give the Sprite a good going over to make sure it was safe to operate. Engine compression was good but it was in need of some minor mechanical work. Dad asked Garland to prepare an insurance appraisal of the car and it is found below:



We had read that converting the drum brakes on the front of 948 Bugeye to disc brakes from a later Sprite or MG Midget was pretty straight foward. Dad didn’t have the time to make the conversion so he had Garland go ahead and get the parts and install the upgrade. As things turned out, the brakes worked a little too well. Garland had forgotten to remove the check valve from the master cylinder and consequently the rear brakes kept locking up and overheating. After making some calls and emailing some sprite owners, Dad figured out the problem and took care of it. Brakes were much improved but still not as good as hoped. We would later find out that the 1098 Sprite with disc brakes used a 3/4” bore master rather than the 7/8” found in the earlier bugeye.

So the disc brake conversion became the first of many “improvements” to the Bugeye that we would make. We knew after driving the Sprite on the Washington Beltway with the big trucks passing us, that conversion to a 1275 motor and a Datsun B210 gearbox wouldn’t be far behind.

Dad contacted Rivergate Restoration about purchasing their conversion kit to the Datsun transmission. After talking to Bill Perry it was decided that a rebuilt 1275 and a rebuilt Datsun B210 gearbox would be purchased as an assembled unit. The Rivergate folks are great to work with.Their contact information is below:
Rivergate Restoration Products
340 Reavley Road Sale Creek, TN 37373
423-332-2030 (Fax: 332-6914)

[email protected]


If one was sourcing a gearbox, the following guidance is provided by Rivergate:


Sprite/Midget 5-Speed Kit Transmission Required

A Datsun 5-speed transmission from August 1979 to 1982 Datsun 210. This can be from a coupe, sedan or wagon.
The input and output shafts should be 20mm (about 25/32″) diameter and 18 spline.

The serial number on top of the bellhousing should begin with the letter “F” (FL, FA, FX etc. OK).

The number “60” is cast into the right side of the main case.  These transmissions come from the Datsun 210, but the model number for these cars, imbedded in the Serial Number, is B310.

The model number for the transmission, FS5W60A, is sometimes found on the Serial Number plate on the firewall. This is not found on the transmission.


When the transmission is bought, the gearshift lever, throwout bearing carrier and clutch release fork are needed.

The Rivergate Five Speed Conversion Kit includes:

An aluminum adapter machined from a billet of 6061 aluminum
A rear crankshaft seal fitted to the adapter plate to help eliminate oil leaks
A rear motor mount assembly (with 6 durometer 40 pads built in)
A new clutch disc to be used with the standard pressure plate
A pushrod assembly and spacer for the slave cylinder
A plug for the transmission case
A 5/8″ and 3/4″ pilot bushing
Forty bolts and washers for attaching the adapter plate and the transmission
New driveshaft yoke with U-joint installed
Throw-Out Bearing
Rear Transmission Seal
Clutch Alignment Tool

Instructions, detailed, with color photos for clarity

This is the most complete, easiest to install kit ever made for the Spridget. It requires no modification to the engine, the flywheel, the driveshaft, or to the chassis or body of your Sprite or Midget.

Modification Kit Side 1

Modification Kit Side 1

Modification Kit Side 2

Modification Kit Side 2


1.  Adapter Plate: Machined from 6061 Aluminum billet. All tapped holes have helicoil inserts. Attractive and precision. Replaces original steel plate. The plate includes a rear crankshaft seal integrated into the design.

2.Clutch Slave Cylinder and Hose: You may use the original slave cylinder presently on your Spridget or the billet aluminum cylinder with stainless steel braid covered Teflon hose we offer.

3. Inside:  New clutch disc that works with stock pressure plate.  No mods to flywheel.  New pilot bushing included.

4. Transmission: Five speed overdrive, all synchronized.   From 1979-82 Datsun 210.  Buy locally or from sources listed here.   Expect to pay around $200.00 — maybe less.

5. Gearshift Lever:  Shorten it to match length of stock lever.  Will use either 5 speed knob or stock Spridget knob.

  1. Driveshaft Yoke: Installation of yoke and U-joint adapts driveshaft without any cutting or modification.
  2. Speedometer Angle Ratio Adapter:  Part of Angle Ratio Adapter and Speedometer cable kit.  Custom geared to match the rear end ratio and tire circumference on your car.   Corrects speedometer reading and makes cable installtion easier and more reliable.   Optional item.
  3. Transmission Mount Assembly:  Bolts in like stock unit, with bolts up through the crossmember.  Utilizes six durometer 40 pads.
  4. Starter Clearance Hole Cover:  An optional item, primarily for appearance.  Only needed for kits purchased before September 2000.

A Rear Crankshaft Seal System was installed in the 1275 motor we purchased. Rivergate had developed a rear crankshaft seal for Sprites & Midgets. The seal system uses a spring backed neoprene seal, and is incorporated into the aluminum transmission conversion adapter plate. It applies to 948, 1098 and 1275cc engines. No engine teardown nor modification is required for installation, but the engine must be out of the car. It is designed to stop oil leaks at the rear of the engine whether they are from around the crankshaft itself, or if the leak is thru the machined surface between the block and the rear main bearing cap.

The crankshaft seal arrangement is furnished with a tube of special aluminum sealant. In addition to use with the seal, it is large enough to use to seal the adapter to the back of the engine block and the oil pump cover into the adapter plate.

The crankshaft seal requires a specially machined 5 speed conversion kit adapter plate. The plate is furnished as part of the conversion kit. In addition, Rivergate can re-machine any of our adapter plates built since February of 1996 to accept the seal kit. See the price list for information.

Also available is the service of machining the standard Rivergate adapter plate to allow for installation of the Bolt-on rear crankshaft seal available from several of the Spridget and Mini Vendors.

John's engine1275-1

John’s engine1275-1

John's engine1275-2

John’s engine1275-2






The following specifications describe the rebuilt engine purchased from Bill Perry at Rivergate.

Rebuilt 1275cc Sprite/Midget motor, bored .030″ over to give 1301cc.


Prepared 1275 Engine

Bored .030″ oversize

Pistons – modern 3 Ring, High Compression

Rod, Main, Thrust Bearings

Oil Pressure Release Valve and Spring

All Gaskets, Front Seal and Valve Stem Seals

Water Pump

Oil Pump

Cam – choice of 266 or 276 Kent Performance Cam

Cam followers

Valve Springs – Upgraded Quality

Timing Chain

Valve Guides



Rebuilt 1275cc Sprite/Midget Motor $2,450.00

Balance all Rotating & Reciprocating Parts $125.00

Lighten flywheel – modest lightening for street use $50.00

Aluminum Cylinder Head – Improved flow and performance, Stellite valve seats, 19 pounds lighter than stock, ready for no-lead fuel, bronze valve guides – a beautiful, functional addition to Sprite/Midget – $725 price only applies to a cylinder head purchased with a rebuilt motor.

Additional Options:

New Pressure Plate – should be purchased if balance option is chosen, so it can be balanced with all other rotating parts $69.00

Camshaft – Scatter Pattern SPVP3 or SPVP4, your choice, (others available) $90.00

Convert to 11 studs – Requires Aluminum Cylinder Head and ARP studs $75.00

Tubular Chrom Moly Pushrods $69.00

Convert to use unleaded fuel — bronze valve guides & Stellite valve seats & valves $140.00

ARP Fasteners

Very high quality fasteners as used on most Spridget Race Motors:

Head Stud Set, includes rocker studs $125.00

Main Stud Kit $70.00

Flywheel Bolt Set $18.00

Rod Bolt and Nut Set $106.00


Shipped in custom crate which must be promptly returned.

Crate Core Charge is $125.00  (will be applied to orders when billed and refunded when the crate is returned) $125.00

Crating Charge $35.00

Shipping (actual cost) $120.00 to $450.00

If engine is purchased along with a five-speed overdrive conversion kit, the engine will be assembled with the aluminum adapter plate rather than the stock iron rear plate.