I am glad this topic came up because I, too, need help deciding which kit to buy for my '69 GS400 that will be wearing 15-inch wheels. I only want to convert the fronts to disc right now. And my car is a NON-power car, so no booster. The questions I need help with are: 1. Are these kits intended to only be used with a booster, or will they work on a system that has a non-PB master cylinder? 2. If I can install disc brakes on the front while keeping it non-power, will I be able to stop the car? Or will it require so much pedal strength that only Lou Ferrigno would be strong enough? 3. Would going with 2-piston calipers lessen the leg strength required to stop the car? Thanks guys.
I think there are different master cylinders for each application. It has to do with the diameter of the "piston" that drives the fluid. Also, a disc reservoir needs (or uses) more fluid than a drum. Some Corvettes had 4 wheel disc manual brakes. I saw a pretty good explanation on this at Baer Brakes talking about their master cylinders. In your case you will need to change the master cylinder and if you put disc brakes on the back at a later time probably change it again. GM master cylinders are cheap and I believe they all have a common GM mount.
Here are the Right Stuff manual kits for the 69 https://www.getdiscbrakes.com/parts...onversions/manual-brake-kits/fm-stock-height/
So basically it looks like on that link, the last two kits on the bottom are the only ones that would fit 14" wheels. All the others say 15+ inch wheels...
Jeff said he had 15" wheels. Based on what I discussed with Right Stuff, I think all those at that link for the 69 above are for 15" factory drum brake wheels or larger. If it says "Fits factory 14"" or larger disc brake wheels" it doesn't mean "14" or larger factory drum brake wheels.” That is what threw me off before. I think this is the only kit they have for manual disc brakes for 14" wheels: https://www.getdiscbrakes.com/afxsd14a
Thanks for that info. I do recall that my '67 Vette had non-power brakes and they worked pretty good. Glad to know that even though I will need a new master cylinder, it won't cost me too much.
Correct, I am now running 15- inch Rallye wheels that probably came off a 1970s car. I want a little more ground clearance so my headers won't scrape on speed bumps. Thanks. I guess that's the kind of kit I will be needing. Am I correct in assuming that 15" Rallye wheels are "disc brake wheels" ?
By the way, I was hoping that I could use this kit from the Parts Place because it's cheap and includes rotors and calipers: https://www.opgi.com/brake-systems/...ke-conversion-1964-72-a-body-kit-ch24821.html but now I am thinking it requires a power brake booster, so I may be outta luck on using it.
To be honest, I am not sure what “disc brake wheel” means exactly other than there has to be enough room for the calipers. I guess if those rallye wheels came off of a car with disc brakes they’d be “disc brake wheels.” I think you will have less problems with the 15” rallye wheels than with the 14” rallye wheels I have. You should be able to use any of the 15” manual disc brake kits and don’t have to use the 14” kits. I may be mistaken but I think you can use that OPGI kit but need to get the correct master cylinder and disc/drum proportioning valve for manual front disc brakes/manual rear drum brakes.
That is encouraging! I plan to ask the OPGI experts about this possibility tomorrow during their office hours. I will post their answer in case it might help anyone else here who could use the info.
OPGI Update: Their tech line is down, but I did find the following questions already answered by them about this particular kit: Q: My 66 el camino is manual brakes will the single chamber master cylinder work? A: Yes, this kit would work with your current set up. Thanks for the question. Q: What size brake pad does this require for future replacement? A: This kit uses a D52 caliper, pads can be found locally. Q: Was wondering why you have to use 15in or larger wheels on your disc breaks conversion kits? I have a 66 GTO and I have 14in on the front w/15in in the rear. And I have had disc on the front for over twenty years. So I'm curious what suppose to happen or go wrong? A: Thank you for the inquiry. Please contact our Technical Support department for immediate assistance toll free at 800-243-8355, and select option 3.
I think you will need a 1-inch bore master cylinder and the disc/drum proportioning valve. I can't find the master cylinder on the OPGI website for a manual brake system, but I think this is the upper kit from Right Stuff, although not sure if it's a good idea to mix brands or not. https://www.getdiscbrakes.com/g0571 You can look at the components tab and see the parts that it comes with. I think this is the comparable full upper/lower manual kit from Right Stuff https://www.getdiscbrakes.com/afxsd01c This video starting at around 1:50 has some information about manual brake master cylinders: This video is also interesting
Did you end up getting the OPGI kit? I bought the 14” kit from Right Stuff because it showed as in stock, but they weren’t in stock after all. They are still waiting on brackets. Their new ETA is middle of November because of supply chain issues.
I bought a used Wilwood Part # 140-10996 Dynalite Front Brake kit for my 69 Skylark, It works with disc or drum spindles and I'm pretty sure it will work with 14 inch wheels also, Pretty amazing how light the rotors & calipers are....
I had it in my Shopping Cart, but when I saw what the shipping cost would be, I chickened out. Guess I will wait and see what the future holds. Who needs good brakes, anyhow? Our motto is "Go Fast With Class," not "Stop Within a Reasonable Distance."
Lol. They have free shipping but for some reason that part is excluded from free shipping https://www.opgi.com/help/free-shipping
I suspected it was too good a sale to be true! Item: Regularly $200, now $100 Shipping: Was free, now $100
Update: I ordered parts from RightStuff on September 26, 2021. I am still waiting on the brake parts, but I received the booster and master cylinder the next day. Apparently there is some bracket that is backordered. They said the brakes were going to be shipped last week but then had to fulfill earlier orders and ran out of brackets again. Now they are saying middle of February. Anyone else have delays on parts? I am also waiting on armrest pads from YearOne (order 10/21/2021) and floor mats from OPGI (ordered last week and they stated from the get go I wouldn’t receive until March so not knocking them)