240Z – Toyota Disk Brake Conversion

240Z – Toyota 4-Piston Brake Caliper Conversion

I finally got around to doing the Toyota disk brake conversion on the Z. Stock Brakes were original Datsun dual-piston calipers. I had them powder coated black (don’t know what I was thinking – should have done red to match the car). Prior to my rebuild I added slotted, drilled rotors (Motorsport Auto).  These are non-vented rotors.  Vented rotors would use a different “W” branded caliper.  These are three excellent resources that I see referred to often:

There are plenty of more resources available via a Google Search

Stock Calipers with Drilled and Slotted disks

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 New Calipers

I tried the auto recyclers with no luck.  I opted for rebuilt calipers from Pep Boys for $39.99 + $20 core.  This was nice because there were clean and already fully rebuilt.  By the time I had wasted a day in the wrecking yard, bought used parts, cleaned them and rebuilt them, I’d probably be at the same (or more) price.  These came in ‘like new’ condition.

toyota disk brake conversion - Caliper_Box_Label toyota disk brake conversion - New_Brakes_Raw.

 Painting

I painted these red using the Eastwood Ceramic Brake Caliper Paint.   The kit was easy to use, and the instructions were clear.  Two coats left a smooth, glossy finish.  To make life easier, I made little “L” shaped plywood stands to hold the calipers during painting – it made the process so much nicer.

Toyota Disk Brake Conversion Painted Calipers

Painted Calipers

Trimming the Dust Plate

Toyota Disk Brake Conversion Marking_Dust_Plate

Marking the dust plate for trimming

I removed old brake caliper and ‘S’ hard line.  I took off the rotor.  With the dust plate still in place, I loosely mounted the new calipers on the wrong side- that is, toward the outside of the wheel.  This would allow me to run a pencil along the contour of the caliper and trace this onto the dust backing plate.  Using my right-angle-grinder, cutoff disks, grinding disks and a flapper disk, I carefully cut back the backing plate in a natural shape that follows the outline of the calipers very nicely.

Mounted-up

The Toyota disk brake calipers install perfectly as promised.

Toyota Disk Brake Conversion Backing_Plate_4

Backing plate trimmed, Calipers mounted (click for larger image)

There is a ‘right side up’ for these calipers, they MUST be mounted with the bleeder valve upwards.  It is possible to swap sides, and with the bleeder at the bottom, you will NEVER be able to bleed all the air out of the caliper.

Bending new “S” Hard Lines

Toyota Disk Brake Conversion Eastwood_brake_line_tool

Eastwood Brake Line Bending Tool

I used some scrap solid copper wire (12 gauge house wiring) and made a “3D” model of exactly the shape I wanted. Due to the size of the new calipers, the old, simple “S” shape would not work.  I started with 8″ brake line, pre flared.  The bends are very tight and very close to the nuts.  The Eastwood Brake Line Forming Tool  was the perfect tool for the job.  No kinking, very tight turns, very close to the nut.  I would rate this a “must have” for this job.

toyota disk brake conversion - S-Line (Click for larger image)

S-Line (Click for larger image)

toyota disk brake conversion -  S-Line Installed

S-Line Installed (click for larger image)

Finished Installation with Decals

The decal was from TunerDecals.com.   As “Datsun” was not a standard logo, I designed a custom decal that I felt somewhat matched the era.  It was super-easy to apply, but care is recommended.  To be double-safe I clear-coated with a high temperature clear spray paint.  3 years now, and holding up perfectly.

toyota disk brake conversion - S-Line Installed Before and  After

Before and After

Other resources

Brake Master Cylinder

One school of thought is to get a larger-bore master cylinder to compensate for the extra brake fluid required to fill the new, additional space in the larger volume pistons.  I kept the same master cylinder, and it works fine, BUT, the pedal does go farther – therefore the piston in the master cylinder goes farther than it did before.  My master cylinder had some corrosion ‘out there’, at the far end of the normal stroke, and when I pushed the brakes hard, the piston hung-up on the corrosion and the brakes stayed on.  I had the master cylinder re-built and all is fine now.  For a larger bore master cylinder, consider Wildwood.

From zcarnut on Hybrid Z A One Inch Diameter Brake Master Cylinder for the S30 Z Cars

Proportioning Valve

Since this modification changes the front/rear braking dynamics, especially for any type of racing, consider an adjustable proportioning valve like Wildwood.

Mind your spelling

A brake is a mechanical device which inhibits motion, slowing or stopping a moving object or preventing its motion. (source: Wikipedia)

To break is to separate (something) into parts or pieces often in a sudden and forceful or violent way (source: merriam-webster.com)

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