master cylinder question

[_gear2]

I was just wondering if it possible to, and if so what do i have to modify in order to get these slightly different brake setups to work on the same car a mx23. They both have the same bore and bolt patter the only difference being that the old cylinder has oil switches located on the underneath as well as the level switches and the wiring connectors are different. While the new one has them on the caps.

Old Cylinder


New Cylinder


would it be possible to just run the wires from the new cap strip them and just connect them to the wires that where to connect to the old switches? hope that makes sense.
and thanks for any help u can give me.

[_gear2]

can anyone help?

[oldcorollas]

are the old ones pressure swithces and the new ones level switches?

[lexsmaz]

You will only be able to wire up the level sensors only, you will have to leave the pressure switches off .... But you will need to check what the pressure switches did, one may even be the stop light switch, works off pressure to operate the lights, i know some early european cars had that set up, not sure on the jap stuff ...

[_gear2]

The new wires are only float level switches.. I was told the wires from bottom indicate pressure differential if a fault exists... so what your saying is there is nothing i can do about the pressure switches??

[lexsmaz]

Correct ... They will have to be left off, which technically makes the car unroadworthy ..
( No brake fail, warning light system operative anymore )
If they are pressure differential switches only, it is a strange setup ....

[Cuzzo]

What you have to do first is work out in what way does the light turn on?

Does it have power or is it a more of a continuity swich were when joined the light comes on. First check for any voltage usiing a multimeter. From the input wires into the dash to the earth/ground. I none exists which there shouldnt be. If you join the two input wires together does the light come on with IGN on? Should be the case. So then join the level wires to the input wires which when joined make the light come. So when the level drops the light will come on.

[_gear2]

Well a solution still hasn’t been found to this problem… and it’s the only thing left that I really have to do. Any help would greatly be appreciated guys. Ive asked a few people. thanks heaps for all your help so far cuzzo.. but everyone seems to be stumped.. Especially by the fact that the light is ALWAYS on. Well the dash when u put the car into ignition but the rear brake lights are always on as soon as the batter is connected. (though if i disconnect the plug that connects the switch that sits on the brake pedal.. the rear brake lights go out.. and the dash does to.. but humm not all the time.. werid? only sometimes.)
The thing that has got me puzzled is it seems that there is never any power coming from the loom to the master cylinder. I put a testlight and multimeter on a good clean earth and probed the single wire and nothing came on.. this is with the car in ign.
Yet the brake light is always on even with the wire disconnected.
ideas anyone?

[_gear2]

well one part of the problems is solved.. the tail lights was due to a faulty switch

[allencr]

Do you have the rest of the manual? If its got that pic of the pressure switches, it may also have some specs and a test procedure for them, in car & out so you'll get an idea of how it's supposed to operate. How about a wiring diagram to see where they go?

They look like they've only got a single terminal, so all they could do is ground with or without pressure. I don't think it's likely any manufacturer would use a setup like that for their low pressure Brake warning system since the usual sliding-piston-in-a-junction is so simple & straight forward. It would take some relays & mickeymouse to make a pressure differential setup with them, and it would still F'up too often because they will almost never operate at the exact same pressure, except being on/off at zero.

A single pressure operated switch for brake lights seemed to be the standard until tandem/duel systems came along or were required.

[_gear2]

The wiring diagrams are in this thread. (sorry not sure how to link images straight to this page)

http://www.toymods.net/forums/showth...ht=mx23+wiring

i do have the rest of the manual, but aside from showing how to remove and install the oil pressure switches (as it calls them) there is nothing else about them.. so any ideas ?

[allencr]

It shows 2 of them normally closed, going to ground, labeled Brake Warning Switch and wired through the Stop Light Switch, so when the brakes are on and either one of them doesn't open, then the Brake Warning Light will come on. If the Parking Brake Switch or the Level Warning Switches aren't closed.,