Question about S30 rear disc brakes....

[Bambikiller240]

My 73 240Z (I no longer own it) also had some sort of valve mounted on the firewall (center of). Anyone know the purpose of that valve? There wasn't one of these in my 71 or 72 240Z.

[abas]

My 73 240Z (I no longer own it) also had some sort of valve mounted on the firewall (center of). Anyone know the purpose of that valve? There wasn't one of these in my 71 or 72 240Z.

Carl

I think this valve on the firewall in later cars was instead of an inline proportioning valve inboard of the right rear wheel (which is what the earlier cars had). This was the same as on the 260z.

Andrew

[Bambikiller240]

I believe that my 73 had the valve in the right rear also. I'll have to dig around and see if I can find a picture or other info.

[Walter Moore]

Well, now that you all have firmly established that the "pressure regulating valve" near the right rear wheel is indeed a "Proportioning valve", where can I get one?

I just re-assembled the brake lines on my 240Z, and when I tried to bleed the rear brakes I discovered to my horror that the valve in question leaks. (Actually hemorrhage is a more accurate word...)

Both the local Nissan dealer and Motorsports Auto inform me that these valves are N.L.A.

Does anyone have a suggestion of a suitable substitute?

I am afraid to by-pass the thing because I am sure Nissan wouldn't have wasted the money on it if it wasn't needed. (and I don't want the car to brake like my old Pinto, which always stopped sideways.)

Motorsports has an adjustable pressure regulator that is used for disk brake conversions. Has anyone ever used one of those in a stock application?

Junkyards are out of the question. There simply are no old Datsuns in any of the local junk yards here. Besides it looks like the valve I need was only used on the 70 - 73 model, very few of those ever made it this far into flyover country.

Thanks for whatever help you can give.

[waynekarnes]

let me misdirect you ...

i think that the 280z used the same proportioning valve as the 240z. there are two at the local wreckers about 40 minutes from my house.

no idea what they'd charge for that ...

rat bastards don't tell you how much until you've pulled it and are at the counter money in hand ...

i could pick one up for you ... i wouldn't know how to test it ... you tell me what to look for and i'd check it out for you ... unfortunately, someone has already cut the brake hoses and removed the backing plates and such off the rears of both cars.

so ... no brake fluid to pump em up to check for leaks.

i was told that they were engineered to last around 400k miles. what kills em is water .. people not following the datsun service guide lines and changing the brake fluid, every 30k.

check and see if the rebuild kit is still available ... courtesy nisssan .. mention z club on line ... think that Carl B. has the 1st name of a counter person that is extra helpful to club members.

drop me a message off the forum wkarnes @ pacbell.net

let me know if you want me to take a ride to the wreckers.

pay later me , no reason to worry about cash up front ... what ever the cost is and shipping ...

wayne

on craigslist ... maybe contact this guy, see if maybe he has the part ...

i don't know him ...

The Remains of "Galor of Z Parts" - $1 (daly city)

Reply to: anon-39590740@craigslist.org

Date: 2004-08-16, 9:58PM PDT

240z rear hatch w/ "Datsun 240z" Emblem - $65

Passenger side Quarter panel - $70

Passenger side rocker panel (Underneath door) - $50

240/260/280z vented hood complete w/ vents - $125

Passenger side 240z fender - $75

280z fenders - Will fit 240/260z - $80 each or $150 for pair

280z motor (1975-76) Compression tested 160psi all 6 cylinders - $150

280zx turbo hood complete with vents - $75

Passenger side 280zx fender - $50

280zx headlight buckets - $25/each

Misc interior parts - $10-35

clutch pedal assembly (For those who want to convert auto to manual) - $40

z steering wheels w/ horn pad - $30/each

Slotted mag wheels in great condition - $300

72 z parts/bucket driver w/ 2.4L, 5 speed trans, and slotted mags - $700

Prices are negotiable.

maybe this guy too ...

Reply to: anon-38985088@craigslist.org

Date: 2004-08-10, 3:26PM PDT

Hi

i will give you guys a very detailed description of this car.

i purchased my 1977 280z last september for 300 dollars.

the frame is in very good shape and has very minor rusts spots on the rear hatch and under the passanger door. the car was purchased from the original owner. since then i have replaced the MAS as well as the relay that supplied power to the fuel pump. the fuel pump was frozen and was also replaced.

the car was able to start before the fuel pump was installed on starter fluid and the engine sounded in good conditoin.

after the fuel pump was installed the car ran on new gas (i drained out the old stuff) but only ran for a few minutes before the fuel lines bursted. the fuel lines bursted due to old age. i have since then gone out and gotten a alluminium fuel rail off a 280zx. i have not installed it yet but it is included with the car.

also included are enough parts to due a major tune up. i have already replaced the spark plugs, airfilter, and oil filter.

i will include coolant, transmission and differential fluid, some brake fluid, radiator flush cleaner, rotor and cap, even spare in good condition power antenna.

the car is a 4 speed. and will also come with 3 sets of extra rims. this is a 2 seater not a 2+2.

with the price of all the parts and the cost of trouble shotting all teh problems i have spent roughly 1500 dollars.

this car shoudl run smoothly after the fuel rail is on. i simply dont have the ambition nor the means to finish this project.

only serious inquires please

E-mail me or call me at (650) 307-2300

http://images.snapfish.com/33%3A%3C8%3A8%3B23232%7Ffp4%3Enu%3D3243%3E7%3A3%3E2%3B4%3EWSNRCG%3D323266%3B7789%3A5nu0mrj

http://images.snapfish.com/33%3A%3C8%3A8%3B23232%7Ffp63%3Dot%3E2334%3D894%3D3%3A5%3DXROQDF%3E232357%3A86%3C7%3C%3Bot1lsi

http://images.snapfish.com/33%3A%3C8%3A8%3B23232%7Ffp64%3Dot%3E2334%3D894%3D3%3A5%3DXROQDF%3E232357%3A86%3C349ot1lsi

http://images.snapfish.com/33%3A%3C8%3A8%3B23232%7Ffp64%3Dot%3E2334%3D894%3D3%3A5%3DXROQDF%3E232357%3A86%3C%3B%3C8ot1lsi

http://images.snapfish.com/33%3A%3C8%3A8%3B23232%7Ffp47%3Dot%3E2334%3D894%3D3%3A5%3DXROQDF%3E232357%3A8734%3C6ot1lsi

http://images.snapfish.com/33%3A%3C8%3A8%3B23232%7Ffp4%3Enu%3D3243%3E7%3A3%3E2%3B4%3EWSNRCG%3D323266%3B77%3A%3B59nu0mrj

i don't know either of these guys ... just an advertisement on local craigslist

wayne

[Walter Moore]

Actually, the porportioning valve on the 280 is on the firewall. There is a "T" in the brake line near the rear wheels, but the item that is broken on my 240 is the "other" brass object back by the right rear wheel.

I gather from another active thread that the proportioning valve for the 280Z is NLA as well, so buying one of them isn't an easy out either...

Besides, when did Nissan change to rear disk brakes? Was it on the 280Z, or the 280ZX?

[waynekarnes]

right you are. the 280z has it under the master. i oughta remember what i posted earlier ... is my face red or what ???

the 79 zx was the first north american z car to have 4 wheel discs. i had one, with the GL package ...

[redneckz II]

:classic: You can remove the part from the car and bend the brake line over to each other and reconnect it. If you are using the 300ZX vented disc brakes up front and disc brakes on the back, you will most likely not need it. I have the 300ZX rotors upfront with S-12W calibers and 280ZX early calibers and later year rotors on my 71 240Z using the flat plate mount. I just removed it and have added stainless steel brake hoses to the front. The back hoses are still rubber. The system is very balanced for me. I use my car as a track car only now and like it a lot as is. Give it a try and if you don't like it, add the adjustable one to it later if needed. Bleed the system real good after doing all of this to it. The pads I use on front are semi-metal and the backs are organic. Stops a lot better then my old brake setup by far.