When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Looks like I'm going to have lots of time to work on my '79. I intend to continue to work on the underside to clean and paint and perhaps replace some of the rubber suspension components even though they're all intact and surprisingly subtle for their age. I've found nothing but light to moderate surface rust underneath and some large test areas I cleaned, primed and painted a couple years ago are still perfect despite intentionally driving the car in rain a few times.
Am curious about some original finishes.
Were the brake calipers ever coated in anything? If so there's not a hint of it left on mine and the present finish is best described as "heavy (but non-pitted) rust".
The rear leaf spring? If the calipers and spring were never coated is it OK to use a stiff wire brush on a power drill? I'm one who believes that rust on heavy steel and cast iron (and even some specially made thinner steel) forms a protective patina against further corrosion and removing such only causes more of the metal to corrode to again produce that patina.
Your best source for an accurate list of finishes is the NCRS 78-79 Judging Manual.
As a general rule of thumb, cast iron parts were usually left natural, and up to the mid 70's, this would include brake calipers. It appears calipers were painted starting sometime in the mid to late 70's. 78-82's usually had calipers that were painted semi gloss black, and often had dabs of white paint, inspection marks. Stamped steel and sheet metal parts, as well as the frame, were usually painted semi gloss black. The rear leaf spring was painted a light gray color. The drive shaft and half shafts were a natural, spun steel finish, and the drive shaft usually had a couple paint stripe inspection marks, around the shaft. The fiberglass underside of the body was left unpainted, as was the spare tire tube. The reinforcement on the tub was painted semi gloss black, but since it was painted before attaching it to the tub, the aluminum rivets holding it together were left unpainted. The exhaust system was left natural.
Your best source for an accurate list of finishes is the NCRS 78-79 Judging Manual.
As a general rule of thumb, cast iron parts were usually left natural, and up to the mid 70's, this would include brake calipers. It appears calipers were painted starting sometime in the mid to late 70's. 78-82's usually had calipers that were painted semi gloss black, and often had dabs of white paint, inspection marks. Stamped steel and sheet metal parts, as well as the frame, were usually painted semi gloss black. The rear leaf spring was painted a light gray color. The drive shaft and half shafts were a natural, spun steel finish, and the drive shaft usually had a couple paint stripe inspection marks, around the shaft. The fiberglass underside of the body was left unpainted, as was the spare tire tube. The reinforcement on the tub was painted semi gloss black, but since it was painted before attaching it to the tub, the aluminum rivets holding it together were left unpainted. The exhaust system was left natural.
Thanks for the info! It sure looks like my calipers were never painted.
Calipers were never painted from the factory. If you decide to coat them, use a high temperature caliper paint. If you want them to look close to original, but never again RUST, shoot them with a cast iron color paint. VHT makes a hi-temp 'cast iron' color paint that will actually cure to harder condition when heated. And they will never rust again.
my 78 built 79..my experience anyway 28000 when I got it June 19..
- calipers NOT painted..or paint gone
- Rear spring some kind of very durable silver almost metallic paint
- half shafts rusted so assume raw
when I rebuilt calipers evaporust really cleaned up the calipers and stay rust free.. (granted im not driving in snow or rain when I can help it..)
- recently I stripped off the paint on spare tire support brackets..(semi gloss black) and bare fiberglass someone painted silver.. looks great!!
I use laquer thinner , acetone, LA degreaser, wax and grease remover, toothbrushes and rags..in order of aggressiveness...
notes- the paint on trailing arm and spring and support bracket (basically anything besides the frame that was assembled from suppliers) is pretty durable and will hold up to fairly strong solvents.. I used them to remove spray bomb touch up silver and to go back to fiberglass..(wax and grease remover best to start with)
the frame rails and frame will absolutely come off even with a water degreaser..very poor durability.
I went commercial rustoleum (says not for home use) at lowes semi or satin cant remember.. dilute with acetone and used that to touch up any black with air brush.. bought silver but didn't need it as spring coating was very solvent resistant.
Used spray can semi gloss satin flat clearcoat do not remember to protect struts after blasting to original metal.. have not gotten to the half shaft until I replace something there.. lol..
pics if it helps..wish I had pre spray bomb..
note- the spring bolt actually is like polished to.. it shines up nice when I cleaned and buffed..the caliper dust shield on mine pretty crappy but looke dlike maybe originally di chromated/ plated?
my arsenal includes an ultrasonic cleaner (buy biggest you can) great for carbs, jewelry, nuts bolts for cleaning.. blasting and evaporust are my go to derust.
after solvent cleaning.all silver spray bomb came right off with acetone and laquer thinner used sparingly..some airbrush rustoleum. evaporust only after rebuild strut bare with low gloss clear, silver spring (solvent will not touch it )
Last edited by interpon; Mar 25, 2020 at 06:15 PM.
78-82's Corvettes absolutely did come with black painted calipers, and possibly 76 & 77's. Both the 78-79 and 80-82 NCRS judging manuals call for low gloss black painted calipers. To quote the 80-82 manual "Brake calipers are low gloss black, painted before machining and assembly. The machined surfaces are natural - minor rust on these surfaces is normal". I have an 81 that I bought new. It has 44,000 miles on it and still has two of the original calipers installed on it. They are black, as were the two I removed and had sleeved and rebuilt years ago by Lonestar Caliper. I can't confirm it, but I was told that Chevrolet started painting the calipers black around 76-77, because they could be seen fairly well through the optional aluminum wheels, and looked bad rusty?
Somewhere I have pictures of 4 calipers that were removed from a 78 Pace Car with 14 miles on it. The car belongs to a customer of mine, a former Chevrolet dealer in Delaware, who never sold his Pace Car. About 15 years ago, they started to leak, and he gave them me to send to Lonestar to have them rebuilt. Before sending them, I took pictures of each caliper, showing the black paint, and the dabs of white inspection paint. If I can dig those pictures up, I will post them here later.
The NCRS describes the paint on the rear spring as follows; "Thin plastic full-length liners are placed between the leaves of the spring, and are painted light gray along with the spring".
Here are the pictures of the calipers that came off of the 14 mile 78 Pace Car, before I sent them to Lonestar. As you can see, they are just as described in the NCRS Judging Manual, painted black, with the machined surfaces machined after painting, causing them to rust. A couple calipers have white inspection marks, two appear to have light blue marks, and the last one seems like it might have had an orange mark. As I said in my previous post, these are from a 78 Pace Car that was never sold by a dealership in Delaware. This car is well documented and pretty well known within the Corvette community, including by a number of members of the Forum.
Black Painted Caliper with White Inspection Mark
Black Painted caliper with White Inspection Mark
Black Painted Caliper with White Inspection Mark
Black Painted Caliper with Light Blue Inspection Mark
Black Painted Caliper with Light Blue (or white???) Inspection Mark
Black Painted Caliper with Orange Inspection Mark (?)
Caliper painted black before machining process, leaving the machined areas bare and prone to rust
Am working on my daily driver today but might get to the Corvette tomorrow. I'm not the original owner so I'm sure the calipers were re-sleeved or perhaps replaced. If replaced maybe they were older rebuilt ones that were never painted.
Will also look for any evidence of paint on the rear leaf spring but I recall nothing.
I have the Gymkhana suspension--maybe a difference?
Wish i would have known calipers were black when i had them apart..must besome awe fully thin crappy paint originally..
i swear my springs are not primer per say..they seem silver and like dipped..
good luck..
pics while doing would be cool.
edit...i found a before shot of po spray bombsilver
Solvent starting to remove spray paint off bracket..silver over fiberglass came off too
Last edited by interpon; Mar 25, 2020 at 06:22 PM.
Wish i would have known calipers were black when i had them apart..must besome awe fully thin crappy paint originally..
After looking again at those excellent photos from the essentially zero mileage '78 I have to agree that the paint seems to be very thin, purely cosmetic and not intended to last for long.
Like the cast iron master cylinder I suspected that "rust" was the expected appearance over time. Not a hint of rust inside--where it matters--what must be my original master cylinder.
I'd suggest that if these things really matter to you, join NCRS and follow their judging guide. You are getting the abridged version of that here from many very knowledgeable folks with extra time on their hands. Many finishes are also called out in the AIM.
It's your car, though! I like the silver finish calipers I got from Lonestar on my 79, and I put G2 epoxy on my 80's calipers when I rebuilt them to complement the red interior. They have green, too.
All Calipers and Master Cylinder were painted a low gloss black then they were machined in the machined areas surface rust did appear over time. The differential, drive shaft and half shafts were of a natural finish.
The rear spring was a light to medium gray primer; however, the retaining cups are natural and crimped into position. Often, GMU is seen forged along the edge of the lower leaf. Black plastic liners with no signs of paint over spray are between the leaves except for leaf #6 and #7.
The frame was painted semi-flat to semigloss black with Dupont 640 enamel based paint. Drips and runs are acceptable, but not all frames have them. Frames were dip-painted, hanging by the front crossmember. Original paint frames had air bubbles that formed on the rearmost edges of the frame, causing round circles of unpainted metal. Original paint frames will have this on almost all rear edges of the frame.
See the list below for basic info.
Natural Finish
front springs (HR)
ball joints (F & S)
front & rear spindles (F)
tie rod ends (F)
tie rod sleeves & clamps (S & CR)
steering relay rod (F)
some upper inner control arm shafts (F)
Idler arm (F)
axle tubes (E)
washers bolted to upper inner control arm bushings (S)
drive shaft (E)
rear end yokes (F)
rear strut rods (F)
rear spring outer bolt, nut & washers (S)
brake rotors (SC)
washers on control arms & trailing arms (S)
axle flanges (F) universal joint components (F)
Gray Finish shock absorbers, blue gray 1977 and later black
rear spring, primer grey (HR)
Plated brake dust shields (S)
unpolished zinc underbody heat shields (s)
gray phosphate fuel tank (S & W) galvanized
clutch cross shaft (W) unpolished zinc
large washers on top of front shocks (S) gray phosphate
front brake caliper mounting brackets (S) dull cadmium dichromate
Low Gloss
Black p/s piston (SC)
brake calipers (SC)
p/s valve assembly (SC)
rear brake caliper mounting brackets (SC)
stabilizer shaft (F)
Semi-Gloss black
radiator (S)
alternator & AIR braces (S)
air conditioning brackets (S & SC)
upper & lower control arms (S)
trailing arms (S & W)
upper & lower inner control arm shafts (f)
bumper brackets (S)
front crossmember Assembly (S & W)
under car brackets (S)
Gloss black
power brake booster (S) 1968 to early were black 1977 after that they were of a gold finish
Thats great info..
im not trying to dispute those that know more than me...
but it sure seems that the power booster on my 79...and some other research on bone stock show a yellow chromate?
also the fan seems midgloss but ill polish a blade and see..
the shocks i replaced were dated original and were black..i almost kept them but tossed em
edit..added fan..i guess you could say high gloss but more of a 60 gloss imo
Polished up a spot near center..
Last edited by interpon; Mar 25, 2020 at 10:05 PM.
True early production 1977 Corvettes may have a black booster but from that point on a gold finish booster was used. Also in 1977 the shock became a some what dull black finish.
Sorry for the follow-up delay. Decided to stimulate the local economy via a trusted local shop that specializes in Corvettes. I don't push them for time. Gave them Delco professional suspension and steering parts to hear, "You made this easy." Will have a number of hours next week for underneath cleaning while it's on the rack and will provide photos.
As an aside it seems that Delco "professional" grade tie rod ends for our cars have been discontinued. I got three of them with no problem but the fourth has been a pain! After three weeks of waiting with numerous cancellations from typical suppliers I finally found one that was obviously older stock as the box is completely different.
Original FInishes
