69 proportining valve??

[20round]

ok, i have three different brake proportioning valves[the main 5 port one]. one is stamped 43 and 37. and the other one is not readable. does anyone know whitch one is correct for the 69 z28. and is there a test for a good valve if its working right..the repos don't look right so i do not want to get one if don't have to..let me know your ideas..thanks troy

[JohnZ]

All '69 Camaros used the same part (3904270); it's not a proportioning valve - it's just a distribution block, containing the differential pressure warning switch, and has no valving functions at all. The proportioning valve (if equipped) is on the outside of the subframe, below the driver's door.

[20round]

ok,how does the switch get a signal, does the plunger under the presure switch move back and forth in the casting? were in the part number located on the block? each of my blocks seem to have different sized holes in the brass seat inserts? so did drum and disc cars have the same block?? and i do have the block on the frame rail going to the rear brakes.. thanks for the reply..troy

[Steve Shauger]

ok,how does the switch get a signal, does the plunger under the presure switch move back and forth in the casting? were in the part number located on the block? each of my blocks seem to have different sized holes in the brass seat inserts? so did drum and disc cars have the same block?? and i do have the block on the frame rail going to the rear brakes.. thanks for the reply..troy

All that information is detailed in the chassis section.

http://www.camaros.org/suspen.shtml

[20round]

i did not see anything about the 5 port valve. just the frame valve..did i miss it ? let me know thanks troy

[169INDY]

My experiance was in 1985. (1968 SS w/ discs)
Going to a stop and ruptured the dry rotted flex line on the right front disc,,,Pedal went soft and car was sluggish to stop.
Idiot brake light lit-up like a xmas tree.
Pull over to investigate, found fluid leak.
The 'loss' of pressure in (The front hydraulic brake circuit) in relation to the intact rear circuit, pushes (axially) a tapered piston inside the distribution block towards the offending (failed) circuits side. The cone tapered center section of the piston contacts a insulated pin (W/ corresponding Brown wire with boot from your front harness) that effectively completes a ground source for the BRAKE light on the dash, there by iluminating the Brake light. I think this electrical circuit is in parrallel with the foot operated parking brake switch also.

Drained front circuit (Hyd), Purchased New Hose, installed, and removed the switch from the dist block and used a small screw driver to re-center the piston and installed the switch and wire, topped the fluid and blead the system and was back in control of braking.

I belive this system is described nicely in the service manuals also.

Jim

[JohnZ]

Drained front circuit (Hyd), Purchased New Hose, installed, and removed the switch from the dist block and used a small screw driver to re-center the piston and installed the switch and wire, topped the fluid and blead the system and was back in control of braking.

Once the system is repaired and bled (so pressure is equal on both ends of the spool inside the distribution block), just stomping on the brakes once will re-center the spool and the light will go out.

[68Zproject]

Same thing happened to me on the rear of my SS.  Someone cut the brake line.  The light came on as described above.  I replaced the line and re-bled and light went out.