NEW COBALT CALIPERS RECEIVED

[Rick Allen]

Received the new "on sale" $269.99 Cobalt calipers last night from Moss Auto, they look good, are heavy, of course made in China.  They seem to be a correct fit replacement for the original Avanti caliper set-up, except for the 2 pins, which I believe to be for alignment on the Jag brackets, but of course would need to be removed to mount on the Avanti brackets.  

It seems they can be removed easily as they are a type of "roll" pin and probably only press fitted.  One issue I have is that they went me the wrong brake pads, completely different from what would be needed for the Avanti set-up, so I'll need to call them on Monday to get the correct ones sent.  When I do, I can then determine if both the calipers and the pads are a correct replacement fit for my '64 R2; this will probably be into later next week by the time I get the new pads.; stay tuned!,,,

[brad]

Did you not read where the pads have to be special and NOT the Bendix Type? Stock pads will NOT work with these pistons. You need the thicker backing plates of the new pads.

[Dwight FitzSimons]

Moss's website shows the following pads, which look right for a Studebaker (may not be right, but look right).

--Dwight

[Rick Allen]

7 hours ago, brad said:

Did you not read where the pads have to be special and NOT the Bendix Type? Stock pads will NOT work with these pistons. You need the thicker backing plates of the new pads.

It is not an issue of needing special pads and me not knowing that, the correct pads are supposed to be included with the calipers and they were not, the pads they sent me (by the number) are for an Austin Healey.  

Again, they send the wrong pads, see Dwight's post in which he shows the correct pads which I had also located on their website, I will have to call them on Monday (tomorrow) and have them resend!

[Rick Allen]

6 hours ago, Dwight FitzSimons said:

Moss's website shows the following pads, which look right for a Studebaker (may not be right, but look right).

--Dwight

Yes they are the correct pads which should have come with the calipers, they can be bought in either ceramic or semi-metallic, their website does not state which ones are included with the calipers I purchased, semi-metallic are less expensive so I assume that's what they would have sent with the package,,, thanks

Edited June 11, 2023 by Rick Allen
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[Zedman]

Hi Rick- The pistons on your Cobalt cyls are hollow, whereas original Pistons are flat, wide and solid. Stock pads are quite small. Are these pistons going to properly bear on the small 'Bendix' pads?

[Rick Allen]

27 minutes ago, Zedman said:

Hi Rick- The pistons on your Cobalt cyls are hollow, whereas original Pistons are flat, wide and solid. Stock pads are quite small. Are these pistons going to properly bear on the small 'Bendix' pads?

It's not a problem, if you go back and scan some of the previous comments, it's mentioned Cobalt calipers come with special pads to accommodate the different style piston so you don't use the original Bendix pads at all, unfortunately in my case, Moss motors sent me the wrong pads which will delay me a week until I received the correct pads,,,

[Dwight FitzSimons]

38 minutes ago, Zedman said:

Hi Rick- The pistons on your Cobalt cyls are hollow, whereas original Pistons are flat, wide and solid. Stock pads are quite small. Are these pistons going to properly bear on the small 'Bendix' pads?

When Studebaker & Bendix adopted the Dunlop disc brakes, they adopted (and manufactured) an existing complete system, except the caliper (bracket).  Studebaker's caliper had to be designed to fit Studebaker's spindle.  As far as pad fitment is concerned, Bendix designed Stude's caliper to fit a pad already in production by Dunlop for an existing British car.  So, pads for some car (Jaguar?) must be available from Moss Motors, and those will fit Studebaker's calipers.

I'm looking forward to learning whether the Cobalt cylinders work properly, especially whether an Avanti has more braking power with them.  The rim of the Cobalt cylinders presses on the pads.  This kind of design ("cup" piston) is like more modern disc brakes (in 1969-up for GM).

Moss Motors' pads must be used with the Cobalt cylinders.  Concerning pad material, does anyone know which material has a higher coefficient of friction: ceramic or semi-metallic?  We all could use more powerful disc brakes.

--Dwight

[Nelson]

Is the pad thickness the same on these versus stock or is it reduced to account for the thicker backing plate?

Also, I assume these will wear down to metal against metal where as the stock unit has a built in positive stop?

[Footer]

Stock vs. Turner vs. Cobalt. Would be interesting to have a stopping comparison. Mike

[Nelson]

Dwight. Back in the early 70’s John Shanahan told me about a machine/speed shop in South Bend that did a lot of work for Studebaker and that it had lots of performance parts still in stock. I made a point to stop there and check it out. Most of the parts were gone but I was able to buy the remainder (not many) of their R3/4 head gaskets. While there I noticed a lot of lose disc brake calipers on shelves and asked why so many. He said that Studebaker had, I assume, raw cores and they were boring them to different sizes as engineering was trying to balance the braking from front to rear. That made sense to me and considering how well the cars stopped back then I have to wonder if the additional 10% piston area is the right thing to do. I will say that a vacuum failure does make for a dangerous situation and I can sure see your concern. I will be interesting to see what difference these make with engine off braking.

Your concern with engine off braking certainly has plenty of merit. I wonder if a vacuum accumulator might be the best approach. 

[Nelson]

In looking at the photos of the parts, what retains the pad? Maybe those roll pins are there to keep the pads from going down too far during installation?

[Dwight FitzSimons]

14 minutes ago, Nelson said:

Dwight. Back in the early 70’s John Shanahan told me about a machine/speed shop in South Bend that did a lot of work for Studebaker and that it had lots of performance parts still in stock. I made a point to stop there and check it out. Most of the parts were gone but I was able to buy the remainder (not many) of their R3/4 head gaskets. While there I noticed a lot of lose disc brake calipers on shelves and asked why so many. He said that Studebaker had, I assume, raw cores and they were boring them to different sizes as engineering was trying to balance the braking from front to rear. That made sense to me and considering how well the cars stopped back then I have to wonder if the additional 10% piston area is the right thing to do. I will say that a vacuum failure does make for a dangerous situation and I can sure see your concern. I will be interesting to see what difference these make with engine off braking.

Your concern with engine off braking certainly has plenty of merit. I wonder if a vacuum accumulator might be the best approach. 

A larger piston area would have the effect of increasing the force on the rotor, and we can't get too much of that -- or am I missing something?  Avantis don't get very much braking from the 11" non-self-energizing rear drum brakes, so there is little, if any, chance of locking up the rears in a panic stop.  Locking up the rears is what we must fear because the rear of the car will swing around.  I have had that happen on the '83 Pontiac Bonneville with front discs & self-energizing rear drum brakes that I used to drive (Thank you, GM!).  (This is why Studebaker/Bendix used non-self-energizing rear drum brakes on the Avanti.)

Another thought: The thickness of the pads from Moss Motors assume a given rotor thickness.  How thick are Jaguar rotors?

BTW, the metal pad backing hitting the rotor is how I have always known when to rebuild my car's brakes.

Any of the above is subject to correction by anyone more expert than I (which is just about everyone).

--Dwight

[Rick Allen]

1 hour ago, Nelson said:

Is the pad thickness the same on these versus stock or is it reduced to account for the thicker backing plate?

Also, I assume these will wear down to metal against metal where as the stock unit has a built in positive stop?

Looking closely at the Cobalt vs. the original caliper, it seems the Cobalt piston retracts (or is shorter or less deep) than the original piston so it would allow for a thicker pad than the original Bendix,  so it would accommodate the thicker backing plate and provide the same, if not more, pad thickness (wear).

As far as, metal to metal wear, in my experience classic cars are not driven hard or many miles and in my case at least, I won't worry what might happen in 100 years; thanks for your observations and comments!,,,

 

Edited June 11, 2023 by Rick Allen
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[Nelson]

Dwight. I agree, as much as I hate the sound of metal against metal it is a great warning sound that tells you it’s time to replace pads or shoes. The problem with the positive stop on the pads is you don’t realize your ability to make a panic stop does not exist when the pads are at the end of their life. I found that out the hard way and it was a good learning experience. 

[Rick Allen]

43 minutes ago, Nelson said:

In looking at the photos of the parts, what retains the pad? Maybe those roll pins are there to keep the pads from going down too far during installation?

As my previous comments mentioned, I don't have the correct pads yet but my assumption is the pads would stay in place the same as the original Dunlop pads would, and as far as the pins, they are something that may fit into the Jag caliper brackets but not the Avanti ones and should/will be removed, they are only "pressed in" light duty roll pins, other wise the Cobalt caliper is the same,,,

[Nelson]

2 minutes ago, Rick Allen said:

As my previous comments mentioned, I don't have the correct pads yet but my assumption is the pads would stay in place the same as the original Dunlop pads would, and as far as the pins, they are something that may fit into the Jag caliper brackets but not the Avanti ones and should/will be removed, they are only "pressed in" light duty roll pins, other wise the Cobalt caliper is the same,,,

The Stude pads are retained by a center pin on the piston which the Cobalts don’t have. I Imagine they will be fine as is. I think the center pin on the Stude acted to retract the pad with the piston. Most disc brakes just rely on rotor runout to do the same job…. I think?

[Rick Allen]

18 minutes ago, Nelson said:

The Stude pads are retained by a center pin on the piston which the Cobalts don’t have. I Imagine they will be fine as is. I think the center pin on the Stude acted to retract the pad with the piston. Most disc brakes just rely on rotor runout to do the same job…. I think?

Sorry, I assumed you were referring to retaining the pads in the carrier/mounting bracket once assembled, not the piston, so yes it would work like most modern disc brake systems, being the pad is free floating against the piston where as the Stude the pad was attached to the piston,,,thanks

[Dwight FitzSimons]

4 hours ago, Nelson said:

Dwight. I agree, as much as I hate the sound of metal against metal it is a great warning sound that tells you it’s time to replace pads or shoes. The problem with the positive stop on the pads is you don’t realize your ability to make a panic stop does not exist when the pads are at the end of their life. I found that out the hard way and it was a good learning experience. 

I was kidding about waiting for metal-on-metal noise before checking my brakes.  I have always done my own brakes because they are so simple and so expensive.

I have, however, seen worse than even that.  I once found a Pontiac in a junk yard whose pad material was long gone, AND with most of one side of the rotor gone.  That is, the pad backing was rubbing on the ribs between the rotor plates.  "Hey, Joe, what do you think that noise is?"

--Dwight

Edited June 11, 2023 by Dwight FitzSimons

[Dwight FitzSimons]

One thought:  I notice that the cylinders are fully exposed through the holes in my Halibrand wheels.  And, someone has had the "Bendix" discs that were on early '63 Avantis reproduced.  So, maybe one could glue those discs onto the Cobalt cylinders (after machining/sanding the "Cobalt" off).  Just a thought for those who like their cars to look original.

--Dwight

Edited June 12, 2023 by Dwight FitzSimons

[Rick Allen]

I started a new topic to update my evaluation of the Cobalt calipers for those who are interested!

[A0136]

New forum member but long time Studebaker and Avanti owner. I put new pads on my 67 Avanti II a few months ago. 
I used the ceramic pads from Moss.  I only have 50 miles or so on them but they are working good.

 

[Rick Allen]

1 hour ago, A0136 said:

New forum member but long time Studebaker and Avanti owner. I put new pads on my 67 Avanti II a few months ago. 
I used the ceramic pads from Moss.  I only have 50 miles or so on them but they are working good.

 

Thanks, that's good to know that they fit and are working well so far,,,