944 Brakes — Disc, Pad & Caliper Figures and Torques
Factory brake figures for the 944 — new and wear-limit thicknesses for the discs, pad thickness and wear limit, caliper piston sizes, the disc runout and thickness checks, and the hydraulic-system tightening torques. Torques switch between N·m and ft·lb; thicknesses are fixed dimensions in millimetres.
The factory brake figures for the 944 — the numbers behind a pad or disc service and the torques for putting the hydraulic system back together. For the jobs themselves see checking and replacing the pads and inspecting and replacing the discs. These figures are for the 944 with its single-piston floating caliper; the 944 S2 (and the four-piston fixed-caliper running gear) uses thicker discs and is noted where it differs. Torques switch between N·m and ft·lb; the thicknesses are fixed dimensions in millimetres.
Brake discs
| Brake disc | Front | Rear |
|---|---|---|
| New thickness | 20.5 mm | 20 mm |
| Minimum after machining | 19.1 mm | 19.2 mm |
| Wear limit (replace at) | 18.5 mm | 18.6 mm |
A disc may only be machined symmetrically — the same amount off each face — and only down to the minimum-after-machining figure; once it reaches the wear limit it is replaced, not skimmed. The 944 S2 runs thicker discs (28 mm front, 24 mm rear new).
| Disc tolerance | Limit |
|---|---|
| Maximum thickness variation (parallelism) | 0.02 mm |
| Maximum lateral run-out, installed | 0.1 mm |
Brake pads
| Figure | Value |
|---|---|
| Pad thickness, new (front and rear) | 13 mm |
| Pad wear limit | 2 mm |
| Pad surface, front wheel | 92 cm² |
| Pad surface, rear wheel | 63 cm² |
| Total pad surface | 310 cm² |
Replace pads once the friction material is down to 2 mm — measure the lining, not the backing plate. Pads wear as a set; renew both ends of an axle together so the car brakes square.
Caliper
The 944 uses a single-piston floating caliper at each corner. The piston diameter is 54 mm at the front and 36 mm at the rear. (The 944 S2's four-piston fixed calipers use paired pistons instead.)
Checking discs
Two measurements decide whether a disc stays on the car:
- Thickness — measure with a micrometer at about 8 points around the braking surface. The lowest reading is the one that counts; if it is at or below the wear limit, replace the disc.
- Lateral run-out — set up a dial gauge against the disc face with the disc bolted to a true hub. If the run-out exceeds 0.1 mm, first re-index the disc on the hub and re-check; if it still exceeds 0.1 mm, replace the disc.
Tightening torques
| Location | Thread | Torque |
|---|---|---|
| Floating caliper to mount | M12 × 1.5 | 85 N·m63 ft·lb |
| Brake disc to wheel hub | M8 | 23 N·m17 ft·lb |
| Road wheel to hub | M14 × 1.5 | 130 N·m96 ft·lb |
| Brake line to master cylinder, hose, distributor, caliper | M10 × 1 | 12 N·m9 ft·lb |
| Brake-pressure regulator to master cylinder or hydraulic unit | M10 × 1 | 14 N·m10 ft·lb |
| Brake hose to caliper | M10 × 1 | 14 N·m10 ft·lb |
| Bleeder screw, floating caliper | M7 | 4 N·m3 ft·lb |
| Bleeder screw, fixed caliper | M10 | 8 N·m6 ft·lb to 12 N·m9 ft·lb |
| Master cylinder to brake booster | M8 | 21 N·m15 ft·lb |
| Brake booster to adapter | M8 | 21 N·m15 ft·lb |
| Adapter to firewall | M8 | 21 N·m15 ft·lb |
| Bracket on brake carrier or trailing arm | M6 | 10 N·m7 ft·lb |
| Stop screw in master cylinder | M6 | 7 N·m5 ft·lb to 10 N·m7 ft·lb |