Wilwood brake dis(c)appointment

[Edbert]

hehehe, it was neck and neck there for a bit (2 versus 2) but now it looks like we have a rout (6 to 2 say fronts).

I was just recalling on the motorcycle...if I lock up the rear no control issues to speak of, lock up the front and eat some pavement.

 

[rbohm]

as far as setting the prop valve up to which end locks up first, there are two opposing views, and both to an extent are correct. the reason most cars a set up with the fronts locking first is to keep the average driver out of trouble under hard braking. most people dont handle emergency situations very well, especially automotive emergencies, so the car needs to be set up for these people. on the other hand, the better drivers can avoid some of the problems incurred when slight over steer, rear brake lockup, and other situations occur. there are times i recommend that front brake lock up just before the rear, and that is for vehicles that have more than 60% of their weight on the front wheels, like pick up trucks. on the other hand most cars, imo, should have the rears lock up just before the fronts. either way you have to be aware of how the car is set up, and drive accordingly.

 

[68rustang]

I was just recalling on the motorcycle...if I lock up the rear no control issues to speak of, lock up the front and eat some pavement.

In regard to bikes, at the track school I attended last year we were told to completely ignore the rear brake on the track until we got other more important fundamentals down. I understand you were referring to locking one vs the other I was throwing out there what we were taught.

 

[Sundance]

If you have an adjustable proportioning valve, with the car at normal driving load, you should adjust the brakes so that all four wheels lock at the exact same time. The idea is to never lock your brakes, but to modulate them up to the braking threshhold. Most if not all factory vehicles are front biased because vehicle load can differ considerably.

Can you lock the brakes?

What caliper did you use?
Wilwood offers two calipers in the dynalite series for .81 rotors. The differance is the bore diameters.

Bed the pads as previously suggested.
Bleed the brakes (again) vacuum bleed if possible
Use a smaller master cylinder I wouldn't go smaller then (7/8")
Replace rubber lines with teflon/stainless braided
Explore pedal ratio options
Install a booster (hydralic or vaccuum)
If all else fails go to the gym and do lots of squats and calf exersises.

 

[jdowen2]

I picked up a set of Raybestos rear brake shoes and will attempt the install Saturday. S/S braided brake lines were added in front when the new calipers were installed. I will then bed the front pads and see what happens.

 

[mdjay]

I agree about the staying with the KH 4 pistons would have been just fine as stated. All new brakes need a brake in period. The pad selection also makes a big difference. Lastly, I think your biggest friend would be a booster. This is one area that should not be without a "power adder."

 

[jeb134]

I agree, I did the same thing as you on my coupe, the biggest difference was when I added the power booster, it braked better than any car I have had before or since.

 

[68keyblr]

I'll third that....power booster makes all the difference.

 

[68keyblr]

Also, be careful with the Chandler mustang shop. I once ruined a set of front tires because they didn't realign the car after taking off the tie rods and left the sleeve loose...ruined the sleeve and tie rod and the tires. Also, I've found critical bolts not torqued after getting it back.

 

[jdowen2]

I replaced the rear shoes (I hate drum brakes) and the bedded the front pads per instructions here. Stops a tad better but not what I'm looking for. The Mustang shop called and said they had a set up like mine with the exception of a vacuum booster. They let me drive it and there is an appreciable difference. I'll go that route when I get some more money. Got a Kelsey Hayes set up for sale

 

[5.0ina66]

You can add power brakes CHEAP...just use an 87 MustangGT booster. It works with the stock pedal and everything. $100 all done! Better than paying for a PB/4spd pedal
PS: Which Wilwood kit did you get? I still think you got sold a line.

 

[5.0ina66]

Got a Kelsey Hayes set up for sale

PM Me!
Thanks
--Kyle

 

[Rusty67]

The 67 H/K disc brakes had a 1 inch MC cylinder bore from the factory. Now IF the wilwood kit is designed to be a bolt on replacement for your factory setup (and I don't think it is) then you should use a stock type MC. I think that the wilwood kits are made to physically bolt on but I don't think they take the time to check into what MC to run with their brakes. The issue now is that you have a set of calipers that require some bore size what ever it may be. You need to match the MC to the calipers you are using. Find out what they recomend to use for their calipers and match to that. It should make you a much happier boy.

A power booster is nice to have. I have said this a few times now but the 2.3L Fox boosters are suppose to bolt in and fit well because they are slimer. I know for a fact that the SVO MC (I think its 84-86, I know the 86 SVO for sure) is a kickass MC. It has a large fluid volume and a 1 1/8inch cylinder bore. Also, its aluminum so its very light compaired to those old style iron ones. The only problems with it are that the ports are on the opposite side and there is no residual pressure valve in it so you have to add a 10 PSI valve into the drum circuit.

Please remember that you need a residual pressure valve for every drum curcuit !!!!!

Now for my opinion. Adjustable proptioning valves SUCK. They have no place in a daily driven car and should be reserved for race cars where fine tuning is neccesary. I don't even have a stock distrobution block in my car anymore and my car brakes like a demon. I've got the stock 4 piston K/H brakes and stock rear drums with the SVO MC and a 10 PSI wilwood residual pressure valve to the rear drums. My pedal is rock hard and I can lock my brakes ANY time I want to. Just got get on the pedal hard enough. I'm liking my manual brakes but I'm considering adding a power booster for the added braking performance but my brakes are working so well I'm not sure its worth the effort. Ok, enough of that.

Hydrolic systems can be frustrating, just keep working on it and you will get it eventually.

EDIT: I didn't realize there was a second page for this thread......

 

[5.0ina66]

The 67 H/K disc brakes had a 1 inch MC cylinder bore from the factory. Now IF the wilwood kit is designed to be a bolt on replacement for your factory setup (and I don't think it is) then you should use a stock type MC. I think that the wilwood kits are made to physically bolt on but I don't think they take the time to check into what MC to run with their brakes. The issue now is that you have a set of calipers that require some bore size what ever it may be. You need to match the MC to the calipers you are using. Find out what they recomend to use for their calipers and match to that. It should make you a much happier boy.

True...but in all the common ~11" rotor kits I've run across use stock-sized caliper pistons, or very close, so I see no problem with a stock MC. For say, something like the 13" rotor kits, the SVO MC is properly sized and cheapest/best looking

A power booster is nice to have. I have said this a few times now but the 2.3L Fox boosters are suppose to bolt in and fit well because they are slimer.

Not on a manual tranny car. It won't clear the clutch rod in a million years; I tried. A 5.0 booster is a known swap into a manual brake/manual trans 67-68

HTH
--Kyle

 

[Rusty67]

I've got the modern drive line cable conversion, you think it would clear the bracket ? I actually ended up having to grind the bracket down a little bit at the corner to get the wider SVO MC to fit. The cap wouldn't clear otherwise.