# Wilwood Front Disc Brake Mounting Issue



## Layzdude (Jun 14, 2015)

Finally decided to upgrade to front disc on my 68. I went with the Wilwood (WIL-140-15272-R).
It said their may be a fitment issue on some spindles if the top hole is not 5/8. Mine are 1/2. it says to have them drilled to 37/64 then tap to 5/8. Has anyone done this without removing the spindles? If I have to take them out and have a machine shop do it, I would rather just get new spindles. Probably cost me the same. I wish Wilwood would have an option for 1/2. 

Thanks


----------



## Jared (Apr 19, 2013)

I did this on the car. Drilling into the spindle was pretty easy because you already have a large guide hole. I bought a brand new carbide drill bit and used a low speed drill to do it. Tapping it out was pretty easy too. Just take your time and it'll go smooth. Sorry that these pictures are grainy. I did this about 6 years ago now and my old phone had a crappy camera.

One other thing to note on this. You noticed that the threads on the Wilwood wheel studs are bigger than the factory as too?















.


----------



## aseyc (Aug 26, 2020)

What wheel size will you use? Do you think 14" will clear?
Did you change the MC and Servo also?


----------



## Jared (Apr 19, 2013)

I have 15" Rally IIs on my car. The paperwork that came with your brakes will have measurements for a template. I made one out of thin plywood to make sure the brakes would fit. My car had 4 wheel drum so I had to change the MC and proportioning valve. I kept mine as a manual brake car and it stops just fine without the booster. I had to be very careful to get the correct MC since the bore size is different for manual brake cars. I swapped out all of the hard lines, front to rear, while I was at it. Took me a couple weekends to do the entire swap because I ran into a couple things like bad ball joints, family obligations, etc.

I linked this a couple weeks back in the general forum but here is an overview that I put on here several years ago when I did this conversion on mine.









Wilwood front brake


I apologize if this has been answered in the past, but I used the search feature and could not find what I needed. I am looking at upgrading the front drum brakes on my LeMans to Wilwood's Dynolite Pro Series. I like their kit because it uses the factory spindles. Currently I have 15" Ralley...




www.gtoforum.com





Feel free to post any questions you have. I check in here in the early morning and most afternoons. I'll help with anything I remember. I did this in 2016 so some of the details may be a bit fuzzy.


----------



## aseyc (Aug 26, 2020)

Thanks Jared. I did follow your thread recently 
The link from Lazydude in Summit's comments section they are saying that a Drum MC and proportioning valve should work just fine that's why I am re-checking on this. Shipping costs are killer to Europe and not having to bear the extra weight of an MC and booster would be preferred especially considering that I have a brand new drum MC on my shelf.


----------



## Layzdude (Jun 14, 2015)

Thanks Jared. I did not look at the studs on the hub. I will check that today!
Did you start with a 37/64 bit or step up sizes? I have 15 American Racing wheels so that fitment should be no issue. I also bought this system cause it said I could leave the stock lines and cylinder (they were replaced not long ago. Ill keep you posted.


----------



## Jared (Apr 19, 2013)

Layzdude said:


> Thanks Jared. I did not look at the studs on the hub. I will check that today!
> Did you start with a 37/64 bit or step up sizes? I have 15 American Racing wheels so that fitment should be no issue. I also bought this system cause it said I could leave the stock lines and cylinder (they were replaced not long ago. Ill keep you posted.


The hole that's already there is pretty big. I used the size it called for and went for it. I was already running generic style chrome lug nuts so I have mismatched sizes on the car now. The ones on the rear are slightly smaller thread. I figure I'll match the front if I ever upgrade the rear diff.

You may want to double check on the MC. I think the reservoirs may be different sizes front to back when going from drum to disk and the proportioning valve is different too. You may be able to get away with swapping out the proportioning valve for a stock style disk brake unit. The brake bias front to rear for disk brakes is different than for 4 wheel drum. Mine was a no brainer. All of the lines were original and it's possible the MC was too.


----------



## Layzdude (Jun 14, 2015)

Thanks Jared! Yea I checked the lugs and what I have work. I ordered at bit and tap so after the holiday I’ll give it a go. Since it says it’s compatible with the stock set up I will wait and see how it functions. How can you tell if the proportioning valve and MC aren’t compatible? Soft petal ?


----------



## Jared (Apr 19, 2013)

Layzdude said:


> Thanks Jared! Yea I checked the lugs and what I have work. I ordered at bit and tap so after the holiday I’ll give it a go. Since it says it’s compatible with the stock set up I will wait and see how it functions. How can you tell if the proportioning valve and MC aren’t compatible? Soft petal ?


You may want to throw that question in the general forum because the most I can share is what I suspect. The proportioning valve dictates how much pressure goes to the front brakes and how much to the rear. On a drum brake car, this bias is different than for a disk brake car, and 4 wheel disk will be different than just disk in the front. Since most of your stopping force is provided by the fronts, having the bias out of check could cause the car to brake strangely. My guess is it will be most evident during aggressive stops and may not show up at all in normal driving. A soft or hard pedal could happen as could a car that wants to stop sideways if you give it too much brake.


----------



## Jared (Apr 19, 2013)

Oh, and give yourself plenty of time to do the swap. The install is definitely not a finish it up in an hour and a half type of project. The more time you take getting the calipers completely centered etc, the better the result.


----------



## Layzdude (Jun 14, 2015)

Thanks Jared!

I was able to do the drivers side no real issues. I did have to fiddle around with the shims. Got it almost perfect but not exact. Starting the passengers later. Thanks for all the advice.


----------



## Jared (Apr 19, 2013)

Good to hear! Unless your going to autocross or track it, close is good enough. I don't remember actually needing shims on one side, and maybe only one on the other. Mine was pretty close right out of the box but all cars are different.


----------



## Layzdude (Jun 14, 2015)

Just finished up, no instal issues. I have a soft pedal and no brakes but it firms up after I pump the brakes a bit and then it stops. I am guessing air in the system. I did not bleed the rear. So when I get a chance Ill go all around and see if that fixes it.


----------



## Jared (Apr 19, 2013)

I saw you posted in the general chat too. Good choice for this sort of issue. You have a couple good tips to check on that post. One thing I forgot to mention on there is my pedal was/is slightly softer than it was with the front drum, not a lot, but a little. And I seem to remember the brakes taking a little time before they seemed to grab like I thought they should. I'm thinking they needed to bed in so don't go too hard on them the first couple times you drive it. I ran into this on a SN95 Mustang GT recently as well. Swapped out the entire brake system --> pads, rotors, calipers, lines, E brake cables, the works. The brakes felt soft for a while afterwards and only firmed up once I had replaced the e-brake cables (one was bad) and drove it through a few heat cycles. The failed cable was probably the key on the Mustang which is why I still think you should check the rear adjustment and the prop valve. You really do need one for a disk brake car, the MC and booster should work. Wilwood says "will work with stock MC and valve", they probably meant stock disk brake MC and valve. That was the way I read it when I did the swap. All else fails, reach out to Wilwood and ask. 

Good luck and don't get discouraged. Once you get this straightened out, you are going to be really happy with the results. My car was night and day better after this conversion.


----------



## Layzdude (Jun 14, 2015)

Thanks Jared. Yea was looking at the Summit site trying to figure out what P valve to get. I’ll probably reach out to wilwood a see what they recommend


----------



## Jared (Apr 19, 2013)

Layzdude said:


> Thanks Jared. Yea was looking at the Summit site trying to figure out what P valve to get. I’ll probably reach out to wilwood a see what they recommend


If your trying to keep the under hood close to stock, you may want to check Ames as well.


----------



## Layzdude (Jun 14, 2015)

Just a quick update.
Installed an adjustable proportioning valve. I can get the rear to lock up but not the front. As I write this I am gravity bleeding the system again. See if that works. For those who did the conversion how do the brakes feel on your car?


----------



## Layzdude (Jun 14, 2015)

Brakes work a lot better after bleeding them again. The front still won't lock up but I didn't get a chance to fully bed them yet. When I press hard on the brake the brake light comes on for a moment then goes off, is the switch in the distribution block not metered for the proportioning valve? I feel like I have a good pedal.


----------

