Author Topic: Rear disc brake conversion for 14" wheels  (Read 6670 times)

tesgt350

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Re: Rear disc brake conversion for 14" wheels
« Reply #15 on: February 26, 2020, 09:40:55 AM »
I know there is a company that makes a conversion for the 9" rear, just don't know who off-the-cuff.

Remember - you will need a different master cylinder and remove the prop valve for the brakes to work correctly. The stock system sends the bulk of the brake fluid to the front. 4 wheel disc will need roughly equal to all corners.

All the Versalles needs for a master cylinder is the stock one with the rear check valve removed.

The proportion of front to rear braking doesn't change.

There isn't a lot of advantage to rear disc brakes. In fact they seem to have perpetually an issue with keeping the Parking brake operable. With automatic transmission cars, that doesn't matter much because most of that is handled by the transmission.

The main advantage is quicker cooling down from repetitive stops from 100 mph or more and better water jamming resistance.

Other then that, they just look cool.


I have an entire spare Versalles here, minus the banjo, pumpkin and axles.

I would advise, should you decide to go that route, stock Versalles axles are 28 spline and you might want to consider 31 spline Strange axles?

You COULD use a stock 9" Mustang banjo with the Versalles brakes, but you might need to modify the mounting flanges slightly on it?

Just curious,  Might be a dumb question so try not to bash me to hard...…. talking about cooling, I know the Slots are used to help Cooling and to remove Brake Dust on Rotors,  does any one make a Drum that has Slots in them?

shelbydoug

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Re: Rear disc brake conversion for 14" wheels
« Reply #16 on: February 26, 2020, 09:59:05 AM »
I know there is a company that makes a conversion for the 9" rear, just don't know who off-the-cuff.

Remember - you will need a different master cylinder and remove the prop valve for the brakes to work correctly. The stock system sends the bulk of the brake fluid to the front. 4 wheel disc will need roughly equal to all corners.
All the Versalles needs for a master cylinder is the stock one with the rear check valve removed.

The proportion of front to rear braking doesn't change.

There isn't a lot of advantage to rear disc brakes. In fact they seem to have perpetually an issue with keeping the Parking brake operable. With automatic transmission cars, that doesn't matter much because most of that is handled by the transmission.

The main advantage is quicker cooling down from repetitive stops from 100 mph or more and better water jamming resistance.

Other then that, they just look cool.


I have an entire spare Versalles here, minus the banjo, pumpkin and axles.

I would advise, should you decide to go that route, stock Versalles axles are 28 spline and you might want to consider 31 spline Strange axles?

You COULD use a stock 9" Mustang banjo with the Versalles brakes, but you might need to modify the mounting flanges slightly on it?

Just curious,  Might be a dumb question so try not to bash me to hard...…. talking about cooling, I know the Slots are used to help Cooling and to remove Brake Dust on Rotors,  does any one make a Drum that has Slots in them?



I don't think so but if you look at some drum linings, they are segmented into 2" x 2" parcels. That aids in controlling the heat expansion of the linings and also provides for some air circulation around them.

Also, the same rear drums that for instance were used on the backs of the Shelby's were available in a finned version with similar Station Wagon applications. It's the same 2 or 2-1/2" wide drum as the production versions, but with added fins on the outside. (I can take pictures of that one if you need it).

I'm also going to put up on Ebay my spare Versalles set. I'm not likely to ever need them. Look later today if you are interested. I'll post a link and ad for them here as well.
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Bob Gaines

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Re: Rear disc brake conversion for 14" wheels
« Reply #17 on: February 26, 2020, 11:18:29 AM »
The finned drums are the easiest to source compared to the assemblyline type. Truck applications mostly I think. Cobra Automotive have them on their website.
Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

shelbydoug

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Re: Rear disc brake conversion for 14" wheels
« Reply #18 on: February 26, 2020, 01:43:46 PM »
Look at the listings for '69 Torino SW for the finned rear drums. That's where I found mine.

I think the 65 Shelby rear drums are from a SW application originally. The '69 change to finned is just an "upgrade" so to speak.

You should powdercoat them though. They take a terrible beating as far as flaking chunks of rust off of the fins.

I actually had those on my '68 before I went to discs. They are way, way easier to deal with and stop as well as or maybe even better then the discs do?

I'd need to do a scientific study to say for sure. And certainly the parking brake works on them as opposed to maybe works on the rear discs? Depends on what time it is?


The only thing with the drums, you need to get the "drag" just right. I was never good at that.
First time I was on the "track" with the car in Michigan, I could feel the rear dragging when they heated up.

That may have contributed to "doin' the clutch" there. Backing the car off the trailer when I got home...no clutch at all...had to winch it into the driveway.

The big 2-1/2" wide metallic shoes REALLY grip.
« Last Edit: February 26, 2020, 01:47:06 PM by shelbydoug »
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pmustang

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Re: Rear disc brake conversion for 14" wheels
« Reply #19 on: February 26, 2020, 03:34:23 PM »
I import prepare and sell classic stangs in the UK

This statement is 100% true

There isn't a lot of advantage to rear disc brakes. In fact they seem to have perpetually an issue with keeping the Parking brake operable. With automatic transmission cars, that doesn't matter much because most of that is handled by the transmission.

We pull them off and replace with factory drums

The lincoln axled car we did, we had to replace the whole axle assembly due to zero parking brake ability even after installing brand new disk brakes on the axle

shelbydoug

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Re: Rear disc brake conversion for 14" wheels
« Reply #20 on: February 26, 2020, 05:10:45 PM »
I import prepare and sell classic stangs in the UK

This statement is 100% true

There isn't a lot of advantage to rear disc brakes. In fact they seem to have perpetually an issue with keeping the Parking brake operable. With automatic transmission cars, that doesn't matter much because most of that is handled by the transmission.

We pull them off and replace with factory drums

The lincoln axled car we did, we had to replace the whole axle assembly due to zero parking brake ability even after installing brand new disk brakes on the axle

There is no question that the Versalles parking brake mechanism is touchy to say the least. Internally it works with three ball bearing balls that go up an inclined ramp. There is no "muscle" necessary for it to work. Just a 90 degree lever movement, cable actuated.


Its actually an interesting idea. As the balls of up the ramp they exert more pressure on the piston to squeeze the pad.

The piston is self adjusting for pad wear.

Mine works but won't hold on a steep hill. The piston needs more pressure exerted on it.



As I said, I think there is a solution which is using a larger diameter ball in the assembly.

There were no manual transmission Versalles made. With an automatic transmission, you don't even need a parking brake.


I've never come across a technical service bulletin on the subject, but that would help. What I was doing with that system 25 years ago, there was no one to help. I was on my own. I wouldn't be surprised if the "factory fix" was to install the three larger diameter balls on each side.

Those are located in a location where there is no brake fluid and that assembly has accessibility. Mechanics, me included, have difficulty because as far as I know, this is a unique system limited to the Ford Granda/Versalles rear discs. Yes they are listed as a Granada option.

The biggest draw back to them is that hardware parts are no longer serviced for them, So if you are missing one of the actuating levers for instance, you are out of luck.


I would say that I have a similar issue with my Audi TT parking brake. On a steep hill it won't hold. That one is a simple cable operated mechanical device with an adjustment clamp to tighten to make it hold.

An adjustment to that will hold it for a week or so then the same results.


My Taurus SHO, with rear discs, manual transmission, never had a parking brake issue and it was constantly parked on a hill.

My two Contour SVT's, same. No issue.


It depends on the scenario of combinations INCLUDING the composition of the pads themselves. Original Ford pads hold. Aftermarkets? Eh?


Rear drums aren't exactly innocent in this regards either. Just easier to adjust, but once you have them set, there is less problem.


The Corvette rear brake system is probably the best but derived at from the manufacturers school of hard knocks.

The question is, is it worth the efforts to install rear discs? Everyone needs to decide for themselves. Some folks love 'em.


"You pays your moneys and you's takes your chances!" It just the way it is, but rear discs simply put are not a simple bolt on. Just be aware of that.  ;)
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Fair67

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Re: Rear disc brake conversion for 14" wheels
« Reply #21 on: February 26, 2020, 06:27:12 PM »
This car is manual. Factory air car..even though that doesn't matter. I'm trying to talk him out of changing over to rear disc brakes.

The Going Thing

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Re: Rear disc brake conversion for 14" wheels
« Reply #22 on: March 04, 2020, 05:17:13 PM »
I would think it would be time well spent convincing the owner to use 15 " wheels instead of the 14". If using Magstar style in 14" or 15" you may incounter clearance problem .  I am not aware for a replica 14" magstar wheel. Even if it were a 15" the center portion of the 15" magstar was the same center as your typical 14" wheel. The rim necks down in that area which causes clearance problems sometimes with front calipers like when used with a 68 single piton caliper. I imagine it will cause problems with calipers mounted on the rear also .

Are there similar issues with the ten spokes? I am always open to learn!

I have a '76 Lincoln Versalles rear in my car. It has a disc brake set up that is unique to the Versalles and the Granada.
I'm using 15" 10 spokes with it and it allows 295-50-15 tires to fit with a slightly lowered suspension.

I never tried it with a 14" wheel but it's possible but why would you want to?


The ORIGIGINAL (NOT REPRODUCTION) 10 spokes are much tighter on the brake side of the wheel then most any other wheel I've EVER seen, because of the way they were cast.

The current reproduction 10 spokes are machined on the inside and allow more clearances for bigger brakes.

I had to go to those on the front when I put the big Galaxie/68 trans am brakes on the car. Look to these combinations for your answers.


My original parts are all stored here and go with the car to the future caretaker. The Lincoln rear bolts right into the Mustang rear. Pirches are right there and as a benefit are more heavy duty then the orignal housing as well as being the same width as the 65-6 Mustang rear. That is 2" narrower then the 67-8 housing. That's why those tires fit within the wheel wells.
295 -50 -15?  295s won't fit in a stock fenderwell.

Fair67

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Re: Rear disc brake conversion for 14" wheels
« Reply #23 on: March 06, 2020, 09:04:34 PM »
UPDATE: No rear disc brakes! It was decided to renew the factory brakes and rock on. I must admit I am happy we are going this direction instead!

shelbydoug

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Re: Rear disc brake conversion for 14" wheels
« Reply #24 on: March 06, 2020, 09:58:51 PM »
I would think it would be time well spent convincing the owner to use 15 " wheels instead of the 14". If using Magstar style in 14" or 15" you may incounter clearance problem .  I am not aware for a replica 14" magstar wheel. Even if it were a 15" the center portion of the 15" magstar was the same center as your typical 14" wheel. The rim necks down in that area which causes clearance problems sometimes with front calipers like when used with a 68 single piton caliper. I imagine it will cause problems with calipers mounted on the rear also .

Are there similar issues with the ten spokes? I am always open to learn!

I have a '76 Lincoln Versalles rear in my car. It has a disc brake set up that is unique to the Versalles and the Granada.
I'm using 15" 10 spokes with it and it allows 295-50-15 tires to fit with a slightly lowered suspension.

I never tried it with a 14" wheel but it's possible but why would you want to?


The ORIGIGINAL (NOT REPRODUCTION) 10 spokes are much tighter on the brake side of the wheel then most any other wheel I've EVER seen, because of the way they were cast.

The current reproduction 10 spokes are machined on the inside and allow more clearances for bigger brakes.

I had to go to those on the front when I put the big Galaxie/68 trans am brakes on the car. Look to these combinations for your answers.


My original parts are all stored here and go with the car to the future caretaker. The Lincoln rear bolts right into the Mustang rear. Pirches are right there and as a benefit are more heavy duty then the orignal housing as well as being the same width as the 65-6 Mustang rear. That is 2" narrower then the 67-8 housing. That's why those tires fit within the wheel wells.
295 -50 -15?  295s won't fit in a stock fenderwell.

Sure do.
« Last Edit: March 06, 2020, 10:07:50 PM by shelbydoug »
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S7MS427

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Re: Rear disc brake conversion for 14" wheels
« Reply #25 on: March 06, 2020, 10:07:19 PM »
Fair67,

Check with Cobra Automotive for replacement shoes and pads that are an upgrade from stock but don't need to heat up to stop the car.  They sold me a set last year which I'm very happy with.  And they didn't break the bank either.
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Fair67

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Re: Rear disc brake conversion for 14" wheels
« Reply #26 on: March 09, 2020, 11:00:02 PM »
Fair67,

Check with Cobra Automotive for replacement shoes and pads that are an upgrade from stock but don't need to heat up to stop the car.  They sold me a set last year which I'm very happy with.  And they didn't break the bank either.

Thank you for the info. I will be ordering from them tomorrow !

The Going Thing

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Re: Rear disc brake conversion for 14" wheels
« Reply #27 on: March 09, 2020, 11:57:39 PM »
I have 63-65 T-bird rear drums on my Shelby. They are 11 X 3. The E-brake still doesn't hold. I also can't find anyone that will re-line with a metallic or ceramic compound. I couldn't source them via Velvetouch.
           
 

shelbydoug

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Re: Rear disc brake conversion for 14" wheels
« Reply #28 on: March 10, 2020, 07:16:05 AM »
I have 63-65 T-bird rear drums on my Shelby. They are 11 X 3. The E-brake still doesn't hold. I also can't find anyone that will re-line with a metallic or ceramic compound. I couldn't source them via Velvetouch.
         

Any emergency/parking brake can be tricky. Not just the discs. Getting the drag just right is the  tricky part.
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The Going Thing

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Re: Rear disc brake conversion for 14" wheels
« Reply #29 on: March 11, 2020, 03:31:30 AM »
I don't have many miles on the car post the build. They may hold better as they are more contoured to the drum. Brake shoe linings are becoming far and few between for older cars and no one arches them anymore. Quality linings in a riveted format are the least common. I don't care for bonded linings.