Residual valves

scrapdaddy

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Thought I'd ask you hardcore guys this one. I'm going to 4 wheel disc and want to know if you would add the #2 residual valves to both the front and rear? I already have a proportioning valve plumbed in the rear with a #10 valve for when I had drums, it will be removed. My master doesn't have anything in it.

Thanks,
Ron
 

Mace

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Depending on the master you used, it should already have one
 

scrapdaddy

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Master is from a T100, but no valve for the front. Would it hurt to put a #2 valve in the front, also?
 
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I'm going to 4 wheel disc and want to know if you would add the #2 residual valves to both the front and rear?
Ron,



Typically we run 2# residual valves on disc circuit when the master is mounted lower than the calipers to prevent the fluid from draining back to the master, never had the need to put them in a system that has the master mounted on the firewall on disc brakes.
 

scrapdaddy

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J Mack,

That's what I've read, but I also read where guys put them in systems like ours. I was just wondering if it hurt by using them. I have a proportioning valve already in line with the back line.
 
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residual valves are used when your master cylinder is below slave cylinders at rest on level ground. They create drag and heat but are better then having no brakes because the fluid flowed back to the master cylinder when you pulled the lid to check the fluid. Point is the lid holds the fluid in so there's little need for a residual valve.

Also keep in mind that residual valves vary in quality - thus it may say 2# or 10# but it can actually 'hold' more then that. I'd never put them on unless your MC is below the slave cylinder level. Why? because if they hold too much, you'll glaze your pads before you realize there's a problem.
 

scrapdaddy

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I wonder why Toyota puts them in the front circuit of some masters? I'm going to use Wilwood #2 valves, front and rear. I thought if the pads rode on the rotor (no valve) then the pads would glaze over.
 
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glaze comes from overheating the pads - while 2 or even 10# is pretty unlikely to do it, the problem is the valves do stick and put a lot more pressure on the pads/rotors - then they glaze. My point is why add more mechanical things that can fail when you don't need them?
 

scrapdaddy

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I'm just trying to set it up similar to what Toyota had. They use a residual valve in their stock masters (not sure all models, etc.), but thinking this is a gray area. Some guys run them and others don't. Makes for good conversation and maybe I'll learn something.

Thanks for all input,
Ron
 

mr jits

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I'm just trying to set it up similar to what Toyota had. They use a residual valve in their stock masters (not sure all models, etc.), but thinking this is a gray area. Some guys run them and others don't. Makes for good conversation and maybe I'll learn something.

Thanks for all input,
Ron
If you have drums, a residual valve is a good idea. It keeps you from having dead travel in the brake pedal.
 
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scrapdaddy

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I had drums in back with a proportioning valve and #10 residual valve, nothing in the front disc line. I'm now going to all disc and trying to figure out what I all need for the best system. My master doesn't have any residual valves in it, so I thought I would need those in line? Maybe not.
 
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