Wilwood's compact tandem master cylinder sits about 1-1/2" closer to the firewall or booster than the standard tandem. That makes it the pick for tight engine bays, big valve covers and LS swaps, with nearly the same fluid capacity.
Highlights:
- Aluminum body about 1-1/2" shorter (and about 1" wider) than the standard tandem
- 7.8 oz front / 4.7 oz rear reservoir capacity, 1.10" stroke
- Four bores: 7/8", 15/16" (manual, pushrod included), 1", 1-1/8" (booster mount)
- Black E-coat or ball-burnished finish
Valve kit option: The kits add Wilwood's combination adjustable proportioning valve, a mounting bracket and pre-bent stainless lines, so it bolts on as one unit. LH bracket puts the valve on the driver side of the master cylinder; RH bracket puts it on the passenger side. Need just a valve? See our Wilwood Proportioning Valve listing.
**WHICH BORE SIZE DO I NEED?**
Wilwood builds the 7/8" and 15/16" bores with an integral pushrod for manual (non-boosted) brakes. The 1" and 1-1/8" bores bolt directly to a power brake booster (or can run manual with Wilwood's pushrod kit).
| Your setup |
Starting bore |
| Manual brakes, 4-piston front calipers (Dynalite, Dynapro, Classic Series) |
7/8" |
| Manual brakes, 6-piston front big-brake kit |
15/16" |
| Power booster, 4-piston front or 4-wheel disc with stock-size rotors |
1" |
| Power booster, 6-piston front + 4-piston rear big-brake kits (13"-14" rotors) |
1-1/8" |
Rule of thumb: a smaller bore gives more line pressure with a longer pedal; a larger bore moves more fluid for big multi-piston calipers with a shorter, firmer pedal. This chart is our general starting point, not Wilwood's official spec. Not sure? Email Sales@macsgarage.shop with your calipers and booster setup and we'll confirm before you order.
Residual valves: Per Wilwood, drum brakes need an inline 10 lb residual valve. Disc brakes with the master cylinder mounted below the caliper bleed screws may need a 2 lb residual valve. 4-wheel disc with the reservoir above the calipers usually needs none.
Plumbing: Run the primary outlet to the axle with the most total caliper piston area (usually the front), and use an adjustable proportioning valve to set rear bias.
Fitment notes: Universal; not a direct OE replacement. Fits most classic Chevy/GMC trucks and Impalas with a 2-bolt firewall or booster mount.
Part #: Master cylinder 260-14957 (7/8"), 260-14958 (15/16"), 260-14959 (1"), 260-14960 (1-1/8"); kit w/ valve & LH bracket 261-14961 to 261-14964; kit w/ valve & RH bracket 261-15659 to 261-15662. Add -BK black, -P ball burnished.
