Nissan SAS Hardbody, Pathfinder, Frontier and Xterra brake Master Cylinder upgrade .

Updated 1/5/2011

  After a SAS the brakes feel soft due to the increase in Caliper size. When converting the rear to discs from a 87-95 pathfinder the problem is not as bad. But the 1" bore needs to be bigger. The 300ZX (Z32) Twin Turbo uses a 1 1/16 Bore size for 90 and 91 ONLY. There is a proportioning valve built into the Master cylinder designed for 4 wheel discs. Nissan used 2 brands for master cylinders. 

Nissan Part number 46011-30P26 Prod. M/Y:0790-0291
Specification:TOKICO 17/16

46011-30P27 Prod.M/Y:0790- 0291
Specification:NABCO 17/16 

They are labeled with there Bore size. Either BM and / or Imperial sizes.

BM33 = 13/16 , BM38 = 7/8, BM44 = 15/16, BM50 = 1" ---- Stock W/D21 and W/D22 Disc / Drum and Disc / Disc
BM57 = 1 1/16 300zx Disc / Disc

BM50 versus BM57, note the ports are on opposite sides.

90~91 300zx Twin Turbo 3.0L VG30DETT z32. Upgrades For 89~98 240sx With 90~96 300zx Brakes Set Up
Here is comparison of Tokico and Nabco versions.

About $35 -100 on ebay, Rockauto, Autozone etc.

sample 1: 92 Pathfinder example with fitting added

I bought a rebuilt 90 turbo 300zx MC at Autozone for $32. I gave them my old core. First remove the allen bolt with a 5mm allan tool.

Now this leaves a female (Inverted flare hole) So I put in a bubble flare from an old slave cylinder or master cylinder.

Another way to get 3 adapters. Slice an old brake master exposing the inside of the adapters.

Plug versus flare fitting that is missing.

Now just need to swap over reservoirs and re bend the brake lines. Just put base in vise and use two screwdrivers and pry up at the bumps.

Before and after. Easy bolton swap 92 Pathfinder.

Example 2: 1993 D21 

Pick up a  rebuilt 1990 MC for $32 at autozone. Drain old with a syringe. Unbolt and bolton new one with NO reservoir.


Remove the plug and Install an old fitting.

Install MC and rebend the lines before installing the reservoir. Test  reaching the dipstick.

Example 3: 2000 D22 example with ebay NPT adapter

Before install you need to add a fitting in the second front port. Also the Brake lines need to be rerouted to the opposite side. Besides these two differences its a bolt on upgrade.

I bought this adapter and could not get it to fit. Its NPT and I returned mine I bought on ebay.

There is a plug for the ABS and none for ABS applications. You have to add the above fitting to this port.

Installed on a 2000 Nissan Frontier D22 with Dana 44 front and Honda Dana 44 rear with discs.


Note the lines come out the opposite side of stock MC.