I'm tryig to get my Wilwoods buttoned up...

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sharpie

workin' stiff
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Feb 10, 2008
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Davis, CA
Here's the setup:

Wilwood Dynalite Pro Series Front Hub brake kit
Wilwood Dynalite Forged calipers
Wilwood tandem master cylinder
Wilwood proportioning valve (in rear brake line)
Wilwood 10lb residual valve (in rear brake line)
Stock 9" rear drum brakes.

The Problem:
I seem to have a LOT of brake drag up front. I don't notice it much when I tap the brakes normally, but if I hard stop and then take my foot off of the brake, the car doesn't move again, I have to give it some gas. I think the calipers are locking?

Similarly, sometimes I can let off the gas at about 15mph, and the car will actually slow down to about 5mph.

I have checked the master cylinder, the pushrod is all the way out when no brake is applied. I also have made sure that I have the correct lines in the correct ports. The stock MC has a (F) over the rear port and a (R) over the front, so I figured 'front' and 'rear.' The Wilwood MC says that total piston bore area goes in the rear port of the Wilwood MC, so I put the front brake line there.

I have also tried adjusting the proportioning valve, from full brake to the front, to the least brake to the front, to somewhere about the middle. No luck.

While it was sitting in the driveway and no pressure on the brake pedal, I opened one of the caliper's bleed screws. There seemed to be no pressure in them, because the fluid didn't squirt.

I don't know where to go next. I basically have a car that doesn't like to keep going even when no brake pressure's applied. Any help would be greatly appreciated.
 
What is the purpose of the residual valve? Sounds to me like the master is bad. Have you tried talking to Wilwood? I'm sure they have tech people to help you out. I have their kit on the front of my Dart so I'll be checking back to see what you figure out.
Congratulations on your upcoming event!!!!!!!!!!!!!!!!!!!!

Jeff
 
Did you use a adjustable brake rod between the master and brake pedal? It's possible that your brake rod is a little to long and not letting the master fully return.
 
did you break in the pads correctly? did you do hard stops right off the bat? opening a bleeder won't squirt fluid. it should drizzle out.
 
What is the purpose of the residual valve? Sounds to me like the master is bad. Have you tried talking to Wilwood? I'm sure they have tech people to help you out. I have their kit on the front of my Dart so I'll be checking back to see what you figure out.
Congratulations on your upcoming event!!!!!!!!!!!!!!!!!!!!

Jeff

Thanks for the congrats. I think talking to Wilwood is the next step. Unless their master already has a residual valve, the purpose is to keep the rear brakes from locking? I dunno, really, but I read from their site that this is required in the drum brake circuit:

wilwood said:
With drum brakes, a ten pound valve is used to compensate for return spring tension in the drums.

Did you use a adjustable brake rod between the master and brake pedal? It's possible that your brake rod is a little to long and not letting the master fully return.

I checked for that. When I was driving, and it slowed down and stopped, I would pull on the brake pedal backward with my foot. It didn't seem to help it. Additionally, I got under there when it was sitting in the driveway and checked the pushrod and didn't find anything wrong with it.

did you break in the pads correctly? did you do hard stops right off the bat? opening a bleeder won't squirt fluid. it should drizzle out.

I don't know the "correct" way except the way Wilwood told me to do it?

wilwood said:
BRAKES MUST BE TESTED AFTER INSTALLATION OR MAINTENANCE
MINIMUM TEST PROCEDURE
• Make sure pedal is firm: Hold firm pressure on pedal for several minutes, it should remain in position without
sinking. If pedal sinks toward floor, check system for fluid leaks. DO NOT drive vehicle if pedal does not stay
firm or can be pushed to the floor with normal pressure.
• At very low speed (2-5 mph) apply brakes hard several times while turning steering from full left to full right, repeat
several times. Remove the wheels and check that components are not touching, rubbing, or leaking.
• Carefully examine all brake components, brake lines, and fittings for leaks and interference.
• Make sure there is no interference with wheels or suspension components.
• Drive vehicle at low speed (15-20 mph) making moderate and hard stops. Brakes should feel normal and
positive. Again check for leaks and interference.
• Always test vehicle in a safe place where there is no danger to (or from) other people or vehicles.
• Always wear seat belts and make use of all safety equipment.

As for the brake bleeder, I just checked to see if it'd squirt, because if it did, it would mean that there's residual pressure in it when the brakes aren't applied, which would be a problem.
 
It's possible that even with the brake pedal all the way back, and the master mounted that the brake rod is to long and applying pressure, as it's being squeezed between the piston and the pedal.
 
I just ordered the exact same set up for my 69 dart,should be here thurs and going in saturday.
The only thing I didn't get(they didn't say I needed it)
was the
adjustable brake push rod
or
Residual valve with fittings !

Is this a "must" before I start to install I want to make sure all will go right.
Thanks,Tim
 
I would get the front on Jack Stands.Disconnect the brake rod.See if the front brakes still have drag.If they spin freely rod adjustment problem.If not check the way the calipers are mounted make sure they are mounted correctly and nothing is binding.As a last resort disconnect the front brake hose at frame and rubber hose.What trying to accomplish to see if your problem is mechanical or hydraulical.Hopefully this makes sense and helps you out.
 
I just ordered the exact same set up for my 69 dart,should be here thurs and going in saturday.
The only thing I didn't get(they didn't say I needed it)
was the
adjustable brake push rod
or
Residual valve with fittings !

Is this a "must" before I start to install I want to make sure all will go right.
Thanks,Tim

The new pushrod comes with (or should come with) the master cylinder. You'll need it as the original one's a bit different in its integration. As for the residual valve, I'll let you know tomorrow, I am pulling mine out and seeing whether I need it in there or not.
 
You don't need the residual pressure valve. Ma Mopar put expander cups in the wheel cylinders that renders a residual valve unnecessary. Sounds to me like that is the source of your problem.
 
It's my understanding that a residual pressure valve is needed when the master cylinder is mounted below the floorboards (lower than the wheel cylinders).in a standard configuration you should not need one.
 
It's my understanding that a residual pressure valve is needed when the master cylinder is mounted below the floorboards (lower than the wheel cylinders).in a standard configuration you should not need one.

guys, I can't tell you how much help you've been. Thanks a BUNCH, I'll take care of the residual valve tomorrow :-D:cheers:
 
the adjustable proportioning valve is used on drag or other cars that run skinnies up front and fattys out back to equalize line pressure to both the fronts and rear brakes.I disagree, you need this residual valve to hold the line pressure steady and the valve itsself must be wired correctly,also the residual valve should be wired correctly. I run the wildwood proportioning valve and the residual valve in my car that has factory non power disc and factory drums.thats why your not getting any line pressure. there are too many correct ways to wire both the proportioning valve and the residual valve to mention here. I run a dedenbear delay box,trans brake and a linelock.I dont know what you run. just get the residual valve and the wiring schematics and you will be ok.thats my opinion, I run the residual valve on my 71 dart.
 
What wiring schematics? Here's what I run, just with the prop valve and residual valve in opposite places in the line:

mastercyl.jpg


I have, however, heard of people who aren't running the residual valve with their 10" drums and they're having no problems.
 
no wiring on the proportioning valve or residual valve? heh,I got wiring on both the proportioning valve and the residual valve,must be for the line lock and transbrake huh?
 
maybe if ya clarified your setup better there wouldnt be a problem, but you will need this residual valve.
 
well, I at least know you dont run a transbrake,delay box and probably not a linelock.just trying to help out,
 
sorry friend, talked to a friend of mine and he says to leave the residual valve out. my setup is different from yours,sorry
 
sorry friend, talked to a friend of mine and he says to leave the residual valve out. my setup is different from yours,sorry

no problem, man. I wasn't trying to be condascending, I just wanted to clarify what I had compared to what you had, because I got confused at the wiring. Thanks very much for your help though
 
yes, sharpie ,I apologize ,I just assummed before asking questions. your good to go.
 
Well, I removed the residual valve yesterday. I noticed a bit of a difference, but I am still getting that brake drag. I guess the best thing today is to make sure the rear shoes are just barely dragging the rear drums, right?

Also, I am going to check the front calipers. Since they're fixed calipers, should they be totally clear, or should one pad be rubbing the rotor like floating calipers?
 
they should touch unless you have pad retractors put in to reduce drag. Jack up the front wheels and see how hard it is to spin them, same with the back. The rears are auto adjusting if they are still drum. If there is heavy drag on all four then most likely your master is partially engaged.
 
they should touch unless you have pad retractors put in to reduce drag. Jack up the front wheels and see how hard it is to spin them, same with the back. The rears are auto adjusting if they are still drum. If there is heavy drag on all four then most likely your master is partially engaged.

ahh thanks. that makes sense. I'll try that tonight (after my third-to-last final ever :D)
 
So I have some updated results. As I said before, I removed the residual valve with little help. Well, today I jacked the entire car up (level) and spun the wheels with my hands. The rear wheels spun 1.75-2.5 times before stopping, and the front spun 3-4 times before stopping. Does that sound like the master cylinder is engaged partially? I can't tell.

And so I drove it around the block once more. I did a pretty dang hard stop, and then I removed my foot from the brake. For about three seconds, the car just stayed there, stopped. I even revved the motor a bit with no results, like it was in neutral, but it was in drive. I have no idea what's going on....

More help appreciated.
 
Sometimes the rubber brake lines can deteriorate internally, acting like a check valve. Possible the rear line?
 
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