65 - disk & drum combi

[Michael W.]

I hope you all had a good christmas.

This week I want to figure out whether my disks (front) or drums (rear) are original on my 1965 vette. Could somebody give me a clue on how to check this?

Thanks

Michael

[Joe L.]

Re: 65 - disk & drum combi

Michael------

No Corvette was EVER built with a hybrid disc/drum system. While common on other car models, it was NEVER done for a Corvette as a PRODUCTION installation.

Some 1965 Corvettes (316) were built with drum brakes as a delete-option. It's possible that your car was originally built that way and, later, someone converted it to front only discs. It's a lot easier to add the front-only discs than it is to add the complete 4 wheel disc system.

The only other possibility, dare I mention it, I can see is that the car is a "cobbled together" car. In other words, while titled as a 1965, it was made up from components of a 1965 and other years.

[Mike McKown]

Re: 65 - disk & drum combi

Since the "disc brake delete" option was obviously an attempt to use up excess inventory, maybe a pertinent question would be if the trailing arms on the "disc delete" cars were of the drum brake variety?

[Drew P.]

Re: 65 - disk & drum combi

Hello Michael,
The brake master cylinder is different for drum brakes and disc brakes. Can you describe the configuratuion of the master cylinder your 1965 Corvette? What is the VIN of your car?
Regards,
Drew Papsun

[Bill Stephenson]

Re: 65 - disk & drum combi

------Also,,,I believe there is a difference in the frame between a disc-brake 65 and a drum-brake 65. The drum brake cars were basicly built with a 64 style frame. Wouldnt the difference be around the trailing-arm snubber, if I am remembering correctly???........Bill S

[Michael W.]

Re: 65 - disk & drum combi

Thanks for all the response.

If you can tell me which differences to look for on the frame & trailing arms then I can tell you the result. Personally I have checked this items and I do not see anything strage, like empty cable connections, etc. I will be at my car today so I will shoot some pics.

My VIN: 123197 so late (July) 1965 car, AOS body

Regards,

Michael

[Bill Stephenson]

Re: 65 - disk & drum combi

------I have a fairly slim drum-brake memory, but if we could entice Mike Hanson into this conversation he could really lay the differences for you. Of course there are others equally as knowledgeable.......Bill S

[Dick W.]

Re: 65 - disk & drum combi

Bill you are correct. The disc brake frames have the "notch" to clear the rear calipers.

[Mike McKown]

Taking that a little further:

The '64 frames didn't have the mentioned caliper feature, nor did they have the front crossmember indentation for the BB pulley. Therefore I'd doubt the drum brake '65's used leftover '64 frames.

Maybe I'm mistaken but I thought the drum/disc brake trailing arms had something different about them. Park brake cable bracket? Don't remember. Anyway I think St. Louis received the arms as an assembly and just used up excess inventory.

Am I wrong?

[Wayne M.]

Compare yours with this '64 trail arm assy

That's some late '65 (4 days from end-of-production) for them to be "exhausting" left-over '64 inventory. If your car really is a J61 Drum Brake Substitution (credit) car, it has to be the last drum brake Corvette ever produced !!

A few items to look for. '63-64 trailing arms did not have a parking brake cable clip welded onto the outboard side. Notice the top side of the arm where the spindle and support attach -- there is no extra welded tab (4" by 2_1/4) for the frame bumper to make contact (this tab goes with the indented frame to clear disc brakes). The spindle has no extra holes for disc rivets or parking brake adjusting tools.

That's for starters; there's a whole bunch more --- you didn't say if power brakes or non (either system has different master cylinder w/J61).

I could shoot some pics of one with disc brakes to compare in frame area, if this would help.

[Michael W.]

Re: Taking that a little further:

Wayne - I would appreciate a disc brake trailing are pic for comparison, because I do not fully get the difference.

Also I took the promissed pictures from my car this afternoon and you can find them in my weblog under the URL: http://www.c2registry.org/index.php?...eblogs&wl_id=1

Note that the drums are new - i replaced them - but I still have the old ones.

Looking forward to the feedback.

Michael

[Wayne M.]

2 views of disc brake tr.arm-bumper-frame depress

the autoload pic is of the inboard view on my late '65 (367 cars after yours). Notice the plate I mentioned on top of the arm, at the spindle location. I jacked up the arm to show how this plate will contact the rubber stop. This bumper and bracket do not project outboard beyond the flush surface of the frame (which is depressed for caliper clearance (click on link below)


I have indicated the frame depression area between the two black marker lines.

I just had a quick glance at your pictures, and can see immediately that your bumper bracket projects outboard to contact the trailing arm (without contact plate). This is to be expected on '63-64 Corvettes and (maybe ?) 1965 J61 cars ?? Also I can't detect any depression on the frame.

This is very interesting; if the frame is original to the car, this means that they kept a stock of a few '64 frames, just in case of a disc brake delete car.

Did you have a look at the front X-member depressions as Mike has suggested ? I suppose (in theory) one could have ordered a 396 with J61, and then you'd need the center depression.

[Eric J.]

Re: Taking that a little further:

Michael, Was this an export Vette? Eric

[Michael W.]

Re: Taking that a little further:

Wayne - I will come back on the point which Mike mentioned. Will be on Friday or the weekend, because tomorrow I am not in the workshop.

Eric - I do not know if it was an export. I did not import it from the US, I bought it in Belgium and the car drove there for a while since I found old Belgium coins in there, but what does that say. My key set has French tekst on on, but they are US made.

Michael

[Eric J.]

How to check for export?

Does anyone know if Corvette's were fitted with a hybrid system for export to Europe? in 65 would there be a plaque on the Firewall like 50's export vettes? Eric