On the 67 LeMans, I will be going through a few brake iterations. For instance, right now I have drum/drum upgrading to power (so I can leave the stock valve alone for now) but might go with stock discs and then later 13" C5 discs and rear discs on a 9". I have an adjustable prop valve which will accommodate all of those possibilities, but I don't want to fabricate new lines for everything each time.
What I want to do is un-valve the prop valve that is in there so it is basically a bypassing distribution block instead of custom lines and a distribution block. That way I can keep the brake fault light and use off-the shelf prebent lines during all of these changes.
Possible? Probable? Other ideas?
Look around the inter-web for a mod to jeep proportioning valves. I used it to "undo" the prob valve on my mustang as it was getting virtually no rear brakes after adding the duel pot front calipers (factory option in a later model GT) Worked really well and maintained the safety default that will keep pressure to the other half of the system of one half is compromised.
I don't believe that the four wheel drums have any proportioning in the valve. If it does, its a spring and piston. Just yank it out and add the adjustable. Don't over think it.
There's one thing I don't understand, why would you have to change hard lines to change the brakes at each wheel?
If you want to add fully adjustable bias to a production brake system, this is generally the part to do the job:
http://www.wilwood.com/MasterCylinders/MasterCylinderProd.aspx?itemno=260-11179
You'll have to customize the hard lines to connect to it though - either with all-custom hard lines or cutting & flaring them and using lengths of soft line to connect to it.
GameboyRMH wrote:
There's one thing I don't understand, why would you have to change hard lines to change the brakes at each wheel?
If I were changing from a factory prop valve to a generic distribution block, it would require rebent, re-nutted, and possibly longer lines than if I were hooking up to the factory valve. Just nice to have bolt-in parts instead of trying to flare and rebend my own lines.
Dusterbd13 wrote:
I don't believe that the four wheel drums have any proportioning in the valve. If it does, its a spring and piston. Just yank it out and add the adjustable. Don't over think it.
Someone else had said that. If that's the case, then I can ignore this whole thing. Inline Tube's website hints that it may not be proportioning, but it also says "up to 67" and "67 and later drum or disc except chevelle..." Not a confident yes or no.
Inline Tube's website said:
Since disc brakes were new in 1967, the valve was still being worked out for the next few years. The 1967-70 valves could consist of as many as three elements and the valves would not work properly without all the pieces. Both 1967-70 factory drum and factory disc cars have (or had) a distribution block which is identical whether the car was drum or disc. Although very similar in appearance to a proportioning valve, the distribution block does not alter brake line pressure.
GameboyRMH wrote:
If you want to add fully adjustable bias to a production brake system, this is generally the part to do the job:
http://www.wilwood.com/MasterCylinders/MasterCylinderProd.aspx?itemno=260-11179
You'll have to customize the hard lines to connect to it though - either with all-custom hard lines or cutting & flaring them and using lengths of soft line to connect to it.
Agreed, nice valve. I have one of the generic ones that goes inline on the rear line that I think I will use. Inline Tube even makes pre-bent lines for that exact application.... which will work brilliantly for me if my stock valve is just distribution.
