Any body use one of these on a stock - front disk rear drum set up?? I just put one on my '69 & would like to know what the best way of getting it adjusted is. Can't really drive dovn my street & lock them up...

Anyone else go through this?? Any help would be appreciated...

Scott

I have one. I just drove down my street and locked them up. You don't have to be going very fast. If the rears want to lock first, they will at any speed. Find a parking lot if it's unsafe on your street.

I'm assuming you installed it in the rear line. Also, make sure your rear drums are adjusted up properly. Other than than, TronDD is right. I started with mine turned all the way up, and the rears definately wanted to lock up first, even on sort of softer stops. I just kept turning it down until that went away, and all's fine now.

I'm assuming you installed it in the rear line. :eek: I installed it in the front line, like the oem combo valve was... Figured I needed to reduce pressure to the front disc's...

Did I screw up????? graemlins/clonk.gif

It needs to be on the rear line... I made the same mistake graemlins/clonk.gif

I've never gotten mine to stop locking the rears, but I'm converting to rear discs now, so maybe it'll work properly now.

Just out of curiosity, would it be the end of the world if I leave it on the front?? It would take MAJOR reconfiguring of the break lines to hook it up on the back line...

Again, I figured that I would reduce pressure to the fronts to bal out the breaking power..

PS How exactly does the stock combo valve work on the front, doesn't it reduce the pressure to the front disks?? :confused:

Yeah, if you leave it in the front line, you'll never have good normal brakes. And to tell you the truth, I can't believe you don't have problems with the rears locking right now.

Drums and discs are completely different animals. Drums take relatively low pressure to operate, and they have a "self actuating" design. Meaning that once the shoes grab the drum, they are kind of pressed into the drum even harder, incresing their braking force.

Discs however, take much more line pressure to actuate. Discs don't have the "self actuating" feature either. I have no idea what's in the valve block you took off, but I do know you'll probably not get satisfactory brakiing unless you put the adjustable valve in the rear line. You need full pressure to the fronts. Because you also can't lock the rears, I'd make sure they are assembled correctly and adjusted properly. Good luck! smile.gif

chris

The stock valve would have both the front and rear lines going to it.

You need to reduce the pressure to the rear and leave the fronts alone. I'm afriad you're replumbing the lines. Not properly proportioning the brakes is quite dangerous.

Tim.

to tell you the truth, I can't believe you don't have problems with the rears locking right now.
Actually, I have yet to drive it with the valve installed, just finished it up last night..


Thanks for the info, However I still don't understand how the stock combo valve works, as it was only installed on the front line..

Also, thank you for explaining it is such great detail, much appreciated....

Hmmmm, maybe it's time to go for the rear disk set up :D

Hi ssal396, did you ride have front discs or did you convert? If you converted, what year doner were the parts from?

If the brake system of your '69 was stock, then the item you removed was the metering valve, which does not necessarily reduce pressure to the front brakes, but only momentarily holds off brake pressure to the front. And yes you are correct, only the front brake line would have gone through it. The idea behind the hold-off/metering valve was to make the engagement of the front discs and rear drums more or less simultaneous. Without that front metering valve the front discs will engage before the rear drums will. (This device is NOT a "Combination Valve" as found on later years, which is why only the front line goes through it.)

Also, take that Wilwood proportioning valve off the front line...it does no good there. It needs to go on the rear line, preferably after the distribution block on the frame rail. If the Wilwood is put before the dist. block you'll likely get the "brake" idiot light lighting constantly.

I have a universal prop valve in my 66SS that is the same exact part as the wilwood part with a different logo on the knob. I have no problems with it.

It is said that rear brake shoe springs and adjusters have 100lbs. of pressure pulling the shoes together.

Front brake pads do not have any spring pressure to over come so they will stop first if nothing helps the rears with the "timing" of the rears.

A proportioning valve makes it so that both the front and rear brakes will come on at roughly the same moment (or slightly quicker) because of the rear spring pressure to prevent lockup and help stopping power.

Chris.

Chris, the "Metering" valve makes it so that both the front & rear brakes come on at the same time (like Larry explained). The "proportioning" valve limits the ammount of pressure to the rear brakes. Disc brakes take alot more pressure to operate than drums - thats why you need the proportioning valve plummed to the rear line.

Just so I know I am on the right page.. I need to remove the wilwood prop valve from the front & put in the rear lines, and it goes between the dist block & the rear brakes, right??

Also, will this set up work WITHOUT the use of the metering valve?? I am ASSuming it would, due to the adjustability of the wilwood valve & the ability to bias the brakes as needed..

Thank you for the help, as I am really :confused:

Scott

Yep, you are correct. I installed discs in place of the drums on my 68, and I only used an adjustable vlave in the rear line. I don't have a metering block, and my brakes work great. MUCH better than 4 wheel drums.... smile.gif

I think it would still work> My 66SS has the adjustable valve for the rear line and I dont have a metering valve.

Stops nice and I have no rear lock up problems. I just installed it and left it where they had it in the middle.

To be honest I am not sure what would happen if the you left the metering valve on and installed a the adjustable prop valve in the rear line. I would think it would still work just fine.

And Brian was right, I got confused between the Metering and Prop valves.

Chris.

Thanks, I wasn't thinking of running both the metering valve & the adjustable prop valve.. The only reason I am going through all of this is because the original metering valve was leaking out the back & down the inner fender..

Otherwise, the stock - front disk, rear drum setup was working great..

I just wanted to make sure that the new proporting valve would work properly, in place of the old metering valve..

Again, thanks a TON for all the info & help..
Scott

You don't necessarily have to use the front "metering valve". All it does is slightly delay the onset of the front brakes. I took mine off for a year or so because it went bad. For the time I drove the car without the metering valve, the only noticeable difference was you could actually feel the front brakes coming on before the rears. It wasn't dangerous, just something you would mentally note.

But then again, there's certainly no reason not to use it. If you have one and it functions correctly, there's no harm in using it on the front brake system even if you're going to have a Wilwood adjustable proportioning valve on the rear system.

Thanks all, I got it installed inside the frame rail, but of coarse broke off one of the rear bleaders in the process :mad: ..

Might as well do new wheel cyls. as well as brake shoes...

Why can't ANYTHING go smooth :(