The Plastic Lizard

So I got a set of front brakes from a C5...


And I know I need a bracket and a DRM spring.

Here are a couple questions if you have done this before....

*are the dimensions of the adapter bracket different from 84 to 85 and later? if so does anyone have those dimensions?

*will the c5 brakes fit under my 17x9.5 sawblades with .75" spacers?

*do I use the brake lines from the C5 or the C4?

anything else I should look out for?

JT-Monster-

Subscripbed id like to know how this turns out

vetteoz

IIRC; a upgrade to the 85+ uprights is required
http://forums.corvetteforum.com/1559405884-post23.html
http://forums.corvetteforum.com/1559409525-post27.html

Some info here
http://forums.corvetteforum.com/1558995025-post1.html

mcm95403

I bought the 85-87 spindles to upgrade my 84 when I still had it. The spacing if definitely different and the 85-87 uprights were much beefier around the adapter bolts.

Those "uprights" should take care of you.

The Plastic Lizard

I did find this link http://members.shaw.ca/corvette.84/C5brakes.html

that seems to indicate that the 84 conversion is ok to do. The problem was they put teflon on the 84 bolts and there was a recall. the 85 redesign was to put on larger diameter bolts, and that is why the spindle was beefier.

c4cruiser

Using 3/4" spacers "may" work but you wil just have to try. Note that the spacers will cause the wheel/tire combo to sit that much further out and you may see some interference between the tire and frame at full lock. Some folks who did this swap tried to grind off some of the cooling fins of the C5 caliper for additional clearance. You might want to mount the wheel first to see just what interference there is.

You can use the C4 flex brake lines. The C4 (at least my '87 used a rectangular "banjo-style fitting and there was plenty of flat surface area on the C5 caliper. Just use some good copper washers and bolt 'em up.

I used Earl's lines on my '87 and they were in excellent shape after 6 years! I did get a new set of lines from Doug Rippie. They use Goodridge lines for their product.

Doing the conversion is a good time to do a complete flush of the old brake fluid. I use ATE Super Blue for autocross and track day events and haven't boiled the fluid. I bought Raybestos "Advanced Technology" rotors (p/n 56700 and 56701) from RockAuto Any C5 year will work I also bought Z06 front pads to match up with Hawk HP+ pads in the rear. GM brake pads come with the clips, most aftermarket pads don't have them.

I would get a new set of caliper guide pins and rubber boots just for drill as they are cheap. The small bolts for the guide pins are a generic metric grade 8.8 so get them from something like Lowe's or Home Depot. Use Loctite Blue on all of the bolts. The red stuff takes heat to remove. Torque all the bolts according to the C4 specs. All of the bolts can be re-used; just use a wire wheel on a grinder to remove the old threadlocker and re-apply the Loctite.

johnnymo63

I've read that the spindles need to be swapped out to the 85-87 beefier design, but if you have a source that makes the adapter brackets with the correct holes for the stock size bolts, then I guess you would be okay.

You will need to use C4 brake lines. Bleed the whole system, too.
No need to change the rears, keep those C4, but now would be the time to upgrade to slotted rotors and Hawk HPS pads.

You won't believe how much better your car will stop with these upgrades.

Click the link in my signature to see my C5 upgrade thread. (on my 94)

The Plastic Lizard

so this is the only drawing I have for an adapter. It is listed as 1984-87 but it's really for 85-87


other than the fact that the 84 has 12mm bolts instead of 14, does anyone know if the centers are the same distance apart?

84wannabezo6

I have the 84 spindles and my c5 brakes work great the difference is the bolt diameter so the brackets need to be 84 specific

JrRifleCoach

Don't forget that the 16" turbines will not clear.

Need 17" or bigger wheels.

GKK

He has 17x9.5" Saw blades he wants to use with 3/4" spacers.

The Plastic Lizard

I made brackets out of 3/8" 316 stainless. Some pictures I've seen show a little relief around the larger C5 brake holes. What is that for? Is it necessary...any ideas of dimension?

The Plastic Lizard

Also, what are the dimensions and size of the c5 and 84 bracket bolts.

c4cruiser

Here's a couple of pics that may help you.

In the first pic from my upgrade, notice that the custom bracket uses the original bolts to attach the custom adapter bracket to the spindle. Also note that the bolts used to attach the C5 caliper abutment bracket are Allen bolts. Also note that these Allen head bolts must be short enough to only go thru the custom bracket and thread onto the abutment bracket so that the bolt does not extend past the holes. Also there is not enough room to use hex bolts. You can see how close the rotor is to the abutment bracket.

In the second pic, it gives you an idea of how everything is bolted together. Note how the flex line attaches to the C5 caliper.

The Plastic Lizard

What size are the Allen bolts