Can the mbc be used from a Z31 on a 240?

[SSMini]

What's up guys. I installed the z32 front and rear brake set up on my 93 240. The MBC I pulled from a z32 300zx is no good. Can I use a MBC from a 89 300zx?? I was looking at a 87 300zx MBC (Same part number as a 89.) and it seems like it would work. It also uses all 3 brake line ports, unlike the z32 where you have to remove the center block off cap and install the flare looking piece in order to use the z32 MBC. I did a search and came up with nothing, but I remember reading somewhere about using the 89 MBC but I can not seem to remember where I read it. If any of you know alot about the z31 MBC, do you know if the brake fluid cup from a z32/240sx (Look the same.) would fit on the z31 MBC? Reason for asking is, I can pick up a reman. z31 MBC for 39.00. (No brake fluid cup.) while a new MBC with cup is 130.00+Thanks....

[naed240sx]

It fits but its tiny so there is no point.

[sncs14]

It will fit but it won't work correctly if you have front and rear Z32 brakes.

[SSMini]

Thanks for the reply guys. Is there any other option besides going with the z32 MBC or is that the only option I have in order to get the brakes to work correctly?Thanks for you help guys....

[UNISA JECS]

It fits but its tiny so there is no point.

The only draw back (smaller vs larger BMC) is it will take alot less force to bring your car to a stop with a smaller BMC which is not neccessarily a bad thing and your pedal will have a littel more free play but if you know how to adjust the output rod you can dial about 80% of this out, I like it. FYI the Z32 also came fitted with a 15/16" BMC. The S13 240SX came fitted with a 7/8" BMC.

It will fit but it won't work correctly if you have front and rear Z32 brakes.

It'll work just fine especially the 87-89 Z31 BMC, this year has the lowest split point of them all which is lower than most Z32 BMC BTW, FYI the only Z32 with an advantageous split point is the 94-96 Z32.

Thanks for the reply guys. Is there any other option besides going with the z32 MBC or is that the only option I have in order to get the brakes to work correctly?Thanks for you help guys....

Yea the BMC you already have (Z31).

[SSMini]

UNISA JECS, Thanks for the help. I went and picked up the z31 MBC. If anybody is interested, the MBC fluid cup from the 240sx or z32 fits just fine on the z31 MBC. Now you can use your factory plug. This is a very cost effective MBC compared to the z32 MBC. Thanks again UNISA JECS for the detailed information on the z31 MBC.

[naed240sx]

The only draw back (smaller vs larger BMC) is it will take alot less force to bring your car to a stop with a smaller BMC which is not neccessarily a bad thing and your pedal will have a littel more free play but if you know how to adjust the output rod you can dial about 80% of this out, I like it. FYI the Z32 also came fitted with a 15/16" BMC. The S13 240SX came fitted with a 7/8" BMC.


It is a bad thing. It results in more pedal travel vs a larger MC, and brake pedal travel is always bad. You want minimum travel.

[UNISA JECS]

It is a bad thing. It results in more pedal travel vs a larger MC, and brake pedal travel is always bad. You want minimum travel.


For some people, they dont like it, I run a 15/16" BMC from a Z32 and if you drove my car you hardly even notice the travel but I dialed out as much of the free play travel I could without engaging/ridding the pads on the rotors but if you dont do that then yes there is more free play but not as bad as with the stock 7/8" BMC which has a good amount of play. The Z32 came stock with a 15/16", 1", 1 1/16" BMC BTW.

[naed240sx]

I'm not talking pedal freeplay, I'm talking pedal travel. With smaller MC's you have more travel because you have to push the cylinder farther to move the same amount of fluid.

[sncs14]

http://www.zilvia.net/f/showthread.php?t=96083&highlight=correct+brake+setup

If you look through the linked thread ^ you'll find all the info you need to know for which brake, BMC, and booster combinations were assembled in factory trim for Z32, S14, and a little info for Z31. Decide for yourself what parts you want to use in conjunction, based off that data. The information I posted was taken directly from the various FSM's.

[UNISA JECS]

Well here you go if you want more specs:

91 - 94 S13 240SX (all)
(BTW the only S13 to come with 15/16" BMC are 4WS and ABS equiped models and that wont do anyone good becasue it only has 2 ports)
7/8" BMC
Split Point – 569psi
Reducing Ratio - 0.4
If you have 1000 psi of line pressure, the fronts get 1000 psi, the rears get 569psi + (1000psi -569psi) * 0.4 = 741psi.
-----------------------------------------------------------------------------------------------
Z31 300Z Non-Turbo
Part# 46010-06F00 (07/83 - 09/85) TOKICO
Part# 46010-21P00 (09/86 - 00/00) TOKICO***
Part# 46010-56L20 (07/83 - 09/85) NABCO***
Part# 46010-04P00 (09/85 - 09/86) TOKICO
Part# 46010-04P20 (09/85 - 09/86) NABCO
15/16" BMC
Split Point – 569psi
Reducing Ratio - 0.4
If you have 1000 psi of line pressure, the fronts get 1000 psi, the rears get 569psi + (1000psi -569psi) * 0.4 = 741psi. same as stock
-----------------------------------------------------------------------------------------------
Z31 300Z Turbo and NA
Part# 46010-21P00 (09/86 - 00/00) TOKICO***
15/16" BMC
Split Point - 427psi
Reducing Ratio - 0.4
If you have 1000 psi of line pressure, the fronts get 1000 psi, the rears get 427psi + (1000psi -427psi) * 0.4 = 656psi. 85psi less than stock
----------------------------------------------------------------------------------------------
Z31 300Z Turbo
Part# 46010-22F00 (07/83 - 09/86) TOKICO
Part# 46010-22F20 (07/83 - 09/85) NABCO
Part# 46010-56L20 (07/83 - 09/85) NABCO***
Part# 46010-18F20 (09/85 - 09/86) NABCO
Part# 46010-21P00 (09/86 - 00/00) TOKICO***
15/16" BMC
Split Point – 498psi
Reducing Ratio - 0.4
If you have 1000 psi of line pressure, the fronts get 1000 psi, the rears get 498psi + (1000psi -498psi) * 0.4 = 699psi. 42psi less than stock
-----------------------------------------------------------------------------------------------
90 Z32 300ZX
15/16" w/o ABS Aust. BMC
17/16" w/ABS Aust./Euro BMC
Split Point – 498psi
Reducing Ratio - 0.4
If you have 1000 psi of line pressure, the fronts get 1000 psi, the rears get 498psi + (1000psi -498psi) * 0.4 = 698psi. 42psi less than stock
-----------------------------------------------------------------------------------------------
94 - 95 - 96 Z32 300ZX
1" BMC
Split Point – 356psi
Reducing Ratio - 0.4
If you have 1000 psi of line pressure, the fronts get 1000 psi, the rears get 356psi + (1000psi -356psi) * 0.4 = 614psi. 127psi less than stock