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View Full Version : C3 Brake upgrade complete. 67 Impala.



Cdnpont
09-24-2013, 01:01 PM
For those interested, I just completed a C3 brake upgrade on my 67 Canadian Pontiac Grande Parisienne. (Impala Chassis)

I used;

69-82 C3 spindles and hubs. Ebay items.
69-82 C3 caliper brackets. Ebay and repop.
Wilwood D8-4 Calipers. Kit included braided lines/adapters. Summit.
Russell speed bleeder screws, 1/4-28. Summit.
Parts store rotors. Pattern Dimple drilled and plated by my brother.
Generic Corvette supply splash shields. Offshore.
Parts supply C3 1 1/8 " bore master. Generic rebuild. Shallow hole.
SSBC adjustable proportioning valve. Summit.
Wilwood 10LB residual valve. Inline with rear system. Needed with drums on a Disc/Disc master. Summit.
1969 Impala drum brake steering arms. 67-70 will work with the stock Impala tie rods.
Used the stock power brake booster already in car. Saved some work installing a better looking one. Was a power drum car before the upgrade.

Worthy of note;

Spent some time shimming the rotors to the hub, improved the runout some, but to tell you the truth, I'd say it doesn't seem to matter with these Wilwood calipers. I can't feel any pulsing so far. Used new grade 9 bolts on the brackets and arms. All new bearings/seals/caps in the hubs. Homemade splash shield gasket from cork/neoprene sheet.

Used one OEM caliper bracket, the other is a offshore repop. Went through quite a few before I found two that were fairly straight. The straighter they are, the more parallel the calipers will sit in relation to the rotor. Shimming can help here if req.

Used a pair of 1969 B Body steering arms. Cut the steering stops off in error. I was following the early C3 pattern, and they have no stops. The fact is 67-69 Impala does have the stops. The Impala drum arms are identical to Impala disc arms.

Added the 10LB residual valve in line to the rear brakes (keeps the shoes out at the drum), placed it after the master. Still have rear drums (to change to disc next year). Need the residual as the Disc/Disc master does not have it built in. Added a SSBC adjustable proportioning valve in line after the residual. Mounted it on a bracket that bolts to a booster stud. Made my own lines...and none leaked! Carefully dry fitted all the lines and valves before taking it all apart and bench bleeding the master. Got the air out fairly quickly. No real issues here.

Original master was a deep hole style. New master was shallow.
Carefully measured, cut and ground the end the long pushrod to work with the shallow master. Made absolutely certain there was slight clearance, and that it was not pushing on the piston when the master was bolted up. This is critical.

Bleeding the system was a snap for the most part. Thinking ahead, I installed Russell speed bleeders in the top two bleed screws on each caliper. Used new DOT3 fluid. Left the proportioning valve full open to the rear when bleeding. The rear drums are working well. Pedal feel is absolutely perfect! The Wilwood D8-4 calipers are sweet. Spend the extra, don't bother with the stock 4 piston calipers.

The end result was, after gently seating the pads, unreal braking right from the get go! A huge difference! I have not even closed down or adjusted the rear proportioning valve yet. The car stops true and straight with no rear lockup. I'm also running all global west front arms/struts and a big Addco bar, Edelbrock AIS shocks, so that does play a big role in the tracking under heavy braking. I also have installed a AGR 12.7:1 steering box (AGR 492117), which works great.

Cheers, Mark

Bottom line is, as a good upgrade on the 65-70 Impala, a well thought out, pieced together C3 setup with the Wilwood D8-4's will work fantastic. And even better... everything is easily available to make it happen! It's all future upgradable to bigger also, Calipers, rotors, hubs, etc.

82740

Funny how small a 11.75" rotor can look in a 17" wheel!

82741

10LB residual and SSBC proportioning valve installed.

82742

rose jackets67
12-07-2013, 01:06 AM
Thanks for this post. I'm accumulating parts to do C3 brakes front and rear on my '67 Impala. I have everything but calipers to do the fronts, but am going to go ahead and do Wilwoods.

I have zero experience with fixed calipers and have concerns about getting runout within spec. What did you get runout down to?

Is the splash shield gasket you made for between the spindle surface and the backing plate or elsewhere?

Thanks,
Adam

Cdnpont
12-12-2013, 07:32 PM
Adam, On one side I saw about .006, the other I could only get it true to .009. I can tell you it's time consuming to try to shim them. You need to torque the lugs each time you add or remove shim. Make sure your bearings are tight (actually slightly over tight) before you go to work. You'll probably find the runout is a product of the hub itself. My opinion is that if you can get them to within .015, don't even worry about it. The original thinking with the low runout tolerance was probably put in place to combat air pumping in the oem Delco Moraine calipers. No worry with the O ring Wilwoods. Spend the time to ensure the the calipers sit parallel to the rotors. You can shim a little between carrier and caliper if need be.
Some light runout appears to have absolutely zero effect with these calipers. There is no pulsing whatsoever through the pedal. Smooth as silk with about 1000 miles on them with plenty of hard braking. After a few weeks I did dial down the SSBC rear proportioning valve for better front rear bias.
The one change I might still make, is to go with a 1" bore master over the 1 1/8". I could live with some extra pedal travel in order to build better brake pressure. The 1 1/8" bore takes a good leg on hard stops, and travel is just slightly on the short side.
Cheers and good luck, Mark

Skip Fix
12-14-2013, 07:03 AM
I always thought the Vette spindles looked clost to Impala spindles.

How different is the 64 spindle?