NEW COBALT CALIPERS UPDATE

[Rick Allen]

Now that I received the correct brake pads, I can show how things fit compared to the original Bendix calipers.

1^st, the backing plate of the new Moss/Cobalt pads is much heavier/thicker than on the original pads, which is what Cobalt indicated is needed for their piston design.

2nd, the new pads are about 3+ mm shorter than the original pads which leaves a greater gap between the top of the pad and the silver metal “retainer” that you remove to replace the pads when needed.

3^rd, the roll pins which are installed on the Cobalt calipers, which I originally thought needed to be removed for clearance on the mounting brackets, are there to keep the pad from slipping down in the bracket. That original thin plate needs to be removed as it would interfere with the new piston design of the Cobalt and the roll pins replace it.

I don’t know if that extra gap at the top of the pad would be a problem but I could either slot the silver retainer to move it down, slot the hole in the bracket and that would move it down, or glue an appropriate size piece of metal or other suitable material on top of the pad, and that would take up the gap.  Also, it’s possible nothing at all would need to be done since when the piston (s) move out they will hold the pad from moving (I would think).

It would be some time before I can evaluate the braking power of the new calipers/pads, as my car is completely apart and the engine is in the machine shop.

Initially, for the price of $270 for 4 newly designed calipers, it seems a good alternative, for me at least, especially because I’d like to keep things as original as possible.

The car stopped fine when Stude made it new in ’62 so no reason it won’t now, I’m not a crazy driver and only drive my classic cars occasionally in the better months of the year here in Pennsylvania!

 

 

 

[64studeavanti]

Thanks for doing this. It is good to know there is a more affordable alternative.

[Fourward]

Yes, I am watching this too. I also live in PA. Central PA. If my engine doesn't run because I put it together, I may be going to a machine shop myself. Is yours shop close by?

[Rick Allen]

The shop I use is in Hazleton, Pa., not too many around any more like in the days when these cars were new.

The shop bored my engine to .030, the heads were already done when I bought the car in February but not installed, I ordered all the engine parts myself and I will assemble it when it comes back from the machine shop, the only other thing I will have the shop do is install the new cam bearings,,,,,,

[Fourward]

Yeah, I am close enough to Hazleton. Lets see if my engine runs when I install it. Fingers crossed.

[Zedman]

Thanks for putting this up, Rick, pictures make it all more understandable.

I would expect the Cobalt pads will be simpler to replace than the originals (with that little pin on the piston to be engaged with the rear of the pad). The cost of these is a bargain. I'm all for supporting more-or-less "originality". Looking forward to your on road testing. 👍

[Randy Atkin]

Here we are some 60 years after the debut of the Avanti and brake pads, pistons, cylinders, etc are still available. How long will we be able to buy Cobalt pads - 5 years, 10 years? They could go out of business tomorrow. Then what?  Something to consider.

[64studeavanti]

A valid concern. If one was worried about that, they could purchase an extra set of pads.

In 5-10 years, the original Dunlop pistons may no longer be available. The Sumitomo version is getting scarce, if not already NLA. 

Brakes are a wear item, so replacing the pistons after 5-10 years should not be a real concern.

The good news for Avanti owners is that the Dunlop design was used by many British, Japanese, and other makes. Parts will be available in some form or another.

[Rick Allen]

10 hours ago, Randy Atkin said:

Here we are some 60 years after the debut of the Avanti and brake pads, pistons, cylinders, etc are still available. How long will we be able to buy Cobalt pads - 5 years, 10 years? They could go out of business tomorrow. Then what?  Something to consider.

A google search indicated Moss has been in business since 1921 but Anything is possible! 

For me, brake pads are not an issue, but could be for someone who's Avanit is a daily driver and puts on 15K miles a year of stop and go traffic, a set of new pads will probably last me forever but not for everybody.

As another member mentioned, buy 2 sets of pads, they are very reasonable, $24 for semi-metallic, $32 for ceramic, should last a long time.

Many went to the Turner system which uses the aftermarket conversion brackets to mount the calipers and uses a single piston floating style caliper where as the original Bendix/Dunlop system uses dual calipers for each wheel/pad as do the new Cobalt calipers, which promotes more even wear and braking power it is said.

All in all, any upgrade to the original system is a plus, there will always be a down side to everything!

As always, I appreciate and respect anyone one's comments! 

Edited June 19, 2023 by Rick Allen
Correct Typo

[Zedman]

23 hours ago, Randy Atkin said:

Here we are some 60 years after the debut of the Avanti and brake pads, pistons, cylinders, etc are still available. How long will we be able to buy Cobalt pads - 5 years, 10 years? They could go out of business tomorrow. Then what?  Something to consider.

Avanti's share the same size 2 1/8" Pistons with Jaguars. There's a whole lot more of them than Avanti's. I can't see this product (Or particularly, my generic replacement Stainless steel jobs from the Jag specialist) going out of production for the forseeable future. So long as we retain the Bendix calipers - we will be fine for a long time.

[Dwight FitzSimons]

22 hours ago, Rick Allen said:

Many went to the Turner system which uses the aftermarket conversion brackets to mount the calipers and uses a single piston floating style caliper whereas the original Bendix/Dunlop system uses dual calipers for each wheel/pad as do the new Cobalt calipers, which promotes more even wear and braking power it is said.

The Achilles heel of the original Bendix/Dunlop disc brakes is the very high line (hydraulic) pressure required to operate the disc brakes, so high that, without the boost from the booster, one cannot stop an Avanti.  Think about that.  This is due to the very small pads.  Assuming that the coefficients of friction are equal a larger pad will provide more braking power than a smaller pad.  That's why the Bendix/Dunlop cylinders must push in much harder to stop the car.

True (AFAIK), dual pistons will produce more even wear than a floating, single-piston, disc-brake system.  IIRC, GM introduced 4-piston disc brakes in 1967, but switched to a single-floating-piston system in 1969, and stuck with that design for many years.  That's the design that the Turner and Hot Rods & Brakes systems use.  Those will easily stop a Studebaker without a booster.

The Cobalt cylinders use the same design as "modern" disc brake cylinders, although the pads are still the same small size.  It would appear that the Cobalt cylinders will maintain their effectiveness much longer than the Bendix/Dunlop cylinders, so that is a plus for them.

--Dwight

[Dwight FitzSimons]

2 hours ago, Dwight FitzSimons said:

The Achilles heel of the original Bendix/Dunlop disc brakes is the very high line (hydraulic) pressure required to operate the disc brakes, so high that, without the boost from the booster, one cannot stop an Avanti.  Think about that.  This is due to the very small pads.  Assuming that the coefficients of friction are equal a larger pad will provide more braking power than a smaller pad.  That's why the Bendix/Dunlop cylinders must push in much harder to stop the car.

True (AFAIK), dual pistons will produce more even wear than a floating, single-piston, disc-brake system.  IIRC, GM introduced 4-piston disc brakes in 1967, but switched to a single-floating-piston system in 1969, and stuck with that design for many years.  That's the design that the Turner and Hot Rods & Brakes systems use.  Those will easily stop a Studebaker without a booster.

The Cobalt cylinders use the same design as "modern" disc brake cylinders, although the pads are still the same small size.  It would appear that the Cobalt cylinders will maintain their effectiveness much longer than the Bendix/Dunlop cylinders, so that is a plus for them.

--Dwight

P.S. Thanks to Rick Allen for doing such a good job of reporting the results of his Cobalt cylinders installation.

[64Avanti]

Given an equal coefficient of friction between the pads and rotors the size of the pads will make no difference in wheel torque.   To change the wheel torque you need to change the size of the caliper pistons to get more force for a given hydraulic pressure or change to a pad with a higher coefficient of friction.