Brake upgrades for Granada spindles?

[giantpune]

Not to completely hijack the thread, but this is relevant to my interests. I've got a 69 mustang with some swapped brakes. The car was originally a 6cyl with manual drum brakes.

Receipts show the previous owner used bearings, pads, and rotors for a '75 granada from autozone.
Rear axle is out of a 96 mustang, with those disc brakes.

As far as I can tell, the hard lines, proportioning valve, and manual master cylinder are all original. The car does not stop like you'd expect with 4 wheel disc brakes. I can stomp on the pedal as hard as I want, and the brakes wont lock up any of the tires.

How would you guys go about making the car stop better? Does it need a power booster to be able to really grab the rotors? Or do you need a different master cylinder or proportioning valve?

 

[TheDude]

Sounds like we might be more or less in the same boat. Decent hardware that should be better than stock, but doesn't actually stop great. Mine does have a newer master cylinder and booster though. Not sure how everything else is, but maybe starting with a brake job with new good pads, check calipers for leaks etc and bleed everything would be a good place to start?

 

[midlife]

Braking power is more than just the master cylinder, proportioning valve, discs and pads. There's a strong interplay between the leverage of the pedal to master cylinder, the master cylinder bore, and vacuum boost. Just swapping OEM parts to various junkyard parts can lead to poorer braking power.

My 66 Mustang GT had factory front discs with four individual pods and no boost. Braking was quite good, and foot pressure was moderate. I could lock up brakes if I had to, but I loved that set-up as I could modulate the braking easily with foot pressure. I've also driven a mid-70's GM full size car that if I applied the same amount of pressure, I'd be thrown through the windshield.

Braking systems should be considered in the same class as drivetrains: cam, intake and exhaust manifolds, transmission and rear-end gearing all need to be considered together for maximum performance.

JMHO

 

[Don C]

If brakes shoes or pads are not properly broken in they will glaze and will never stop the vehicle properly. Having the proper finish on the drums and rotors is also critical, as well as keeping the rotors, drums, shoes and pads clean and free from grease and oil.

 

[Sheriff41]

Did you read this thread on that other site? https://www.vintage-mustang.com/threads/big-brake-upgrade-for-granada-spindles.1168853/

 

[TheDude]

No I hadn't. That is interesting. I do like the idea of just bigger OEM brakes so parts are easier to find. Looks like that's still in progress so I'll follow that thread.

Thanks!

 

[TheDude]

Just thought I'd update in case anyone here was interested. I did finally end up doing the upgrade @Sheriff41 pointed out. Got the brackets from the guy on vintange-mustangs since I'm running on 20's (hopefully back to 18's soon), I went with 14" rotors running 4 piston Brembo knock offs. Lot's of trial and error on parts but finally got it all together last week. It's a real Frankenstein brake setup.

• Granada spindles
• 65 Hubs
• Studs from a late model Jeep
• Brake lines from a late model Chevy Truck
• 2013 Boss 302 Mustang 14" rotors and 4 piston Brembo's
• unrelated, but rear brakes from an early 2000's Ford Explorer.
• Wilwood adjustable proportioning valve.

Haven't driven it much yet, still needing to bed the brakes and constantly checking for leaks as it was my 1st time making hard lines since the 80s. They certainly look the part but not really sure what to expect as far as braking performance and pedal feel etc. Hopefully get it out some place away from the city this weekend to get the brakes broken in and setup the proportioning valve.

 

[rackerm]

Your front brakes look fantastic. I wish I had seen your first post four years ago. I never really liked the 70-73 floating caliper design. So on my 1970 Mach 1, I converted my front spindles and drums to Granada spindles with the Granada factory calipers. I just upgraded the rotor. It is still stock 12 in diameter but cross-drilled and slotted. I chose the Granada spindles, as they claim to be stronger with the larger hub than the '70-'73 factory spindles, the calipers are not the floating type, and the factory replacement parts are readily available and inexpensive. Fortunately, I was not planning to use factory wheels, and most aftermarket wheels would fit over the larger diameter hub. I have read that the Granada spindles are thick enough to turn them down on a lathe so they will fit a factory wheel hub diameter. I needed to use the Granada outer tie rod ends which fit right on the factory tie rods, and I used a GM four-disc distribution block and just tied the two Ford brake warning light wires together to one wire GM switch connector. I did have to modify the brake lines to and from the GM block and the Ford Master cylinder. A little Calypso Coral paint on the caliper to match the car.

Power Stop Cross Drilled and Slotted 12" Front Rotors - AR8102XPR

​

 

[TheDude]

That looks sweet and frankly what I should have done as I'm not racing this thing. That said I do hope when all is said and done that this will actually stop better than before.

The hard lines are good point, I do think I'll want to replace the lines that go to each wheel. I ended up using the stock lines which are located at the front of the wheel well. The brembo clones come off at the back of the wheel so I needed a very long brake hose to get it connected, like 20". That's a lot of rubber line which won't help brake feel and more to possibly get tied up in the suspension if there's an issue with support. So I'll probably remake the hard lines at some point to be closer to the caliper.

I really didn't know anything about advantages of the Granada spindles and didn't even know mine had them until I went to replace brake pads and realized the Mustang pads didn't work. I figured it was just an easier way to get to discs, so interesting to hear that there are other advantages.

Also, yours is another car that makes me embarrassed to post any close up pics of my car on here. The underside of your car looks better than the top side of mine . Dragged my car out of a field a few years ago and it's all I could to do to just get it running and driving let alone cleaning off the 50+ years of protective grease on the bottom side.

 

[rackerm]

That looks sweet and frankly what I should have done as I'm not racing this thing. That said I do hope when all is said and done that this will actually stop better than before.

The hard lines are good point, I do think I'll want to replace the lines that go to each wheel. I ended up using the stock lines which are located at the front of the wheel well. The brembo clones come off at the back of the wheel so I needed a very long brake hose to get it connected, like 20". That's a lot of rubber line which won't help brake feel and more to possibly get tied up in the suspension if there's an issue with support. So I'll probably remake the hard lines at some point to be closer to the caliper.

I really didn't know anything about advantages of the Granada spindles and didn't even know mine had them until I went to replace brake pads and realized the Mustang pads didn't work. I figured it was just an easier way to get to discs, so interesting to hear that there are other advantages.

Also, yours is another car that makes me embarrassed to post any close up pics of my car on here. The underside of your car looks better than the top side of mine . Dragged my car out of a field a few years ago and it's all I could to do to just get it running and driving let alone cleaning off the 50+ years of protective grease on the bottom side.

You should never feel embarrassed about posting pictures, we all have been there. I love seeing the progress made over time to resurrect these old rust buckets. I am glad to see you have saved it from ending up on the scrap heap. Good luck with it.

 

[AcesArneson]

Personally, I would go to the expert, give Mustang Steve a try. He makes brake adapters for these cars. I bought a disc conversion from him for using S550 14" up front and 13" in the back. Not sure if he makes the bracket for the Granada conversion but if he does that would give you some serious options to fill out that 20" rim and give you aggressive stopping.

Mustang Steve email: [email protected]

Mustang Steve website: https://mustangsteve.com/product-category/front-disc-brake-conversion-kits/

 

[TheDude]

Thanks @AcesArneson . I'm a little past that now as this conversion is done and looks like it will work out well. Unfortunately just had some other stuff come up with this thing that will keep it off the road for another week or two until before I can work on dialing in the brakes more.

 

[AcesArneson]

Thanks @AcesArneson . I'm a little past that now as this conversion is done and looks like it will work out well. Unfortunately just had some other stuff come up with this thing that will keep it off the road for another week or two until before I can work on dialing in the brakes more.

I hear you. I have been waiting on the engine rebuild for just over a year, scarcity of parts coming out of Covid.