Identification questions

[L48]

I am trying to better identify my 1975 Corvette.

1) I want to confirm the block is in fact numbers matching. Here is the numbers on the block (on the machine surface just in front of the head on the passenger side): 15S409424 V1203CHB. What part of this should match the VIN?

2) The trim tag in the door jam indicates the interior is 14V and the trim is 13L. According to the reference on this site 13 is silver. My car is dark red (see avatar). I have spent a good bit of time looking for the silver paint underneath the red but find no sign of that anywhere. It has been painted alright - repainted the same color red. The interior was originally silver and I can see the silver peeking through on some of the black panels.

Does anyone else have a 1975 car with 13L code and what color is it? Any other insight on this would be appreciated.

 

[fl_rider]

This should help...

http://corvetteactioncenter.com/specs/c3/1975/75prod.html

Production numbers and codes.

I sounds like your car has been repainted, someone didn't like silver.

Chris B

 

[Dave Z]

For your item # 2
My trim tag is 13L. I'm the third owner, and know that the car was silver when purchased new in MD. The second owner was very good friends with the first owner when she purchased it in 1975. He showed me a picture of the day she picked it up with him standing beside her. He bought it from her in 1990 for his wife and had it painted the midnight blue color it is today. He did spend some serious money on the repaint. I can honestly say, that not only is the paint still in good shape, but I can't find any trace of silver on the car. Silver doesn't do it for me either. When the repaint comes I'm going to go probably go with the new C6 sunburst orange color. I have the deluxe black leather interiror and I think lighter exterior colors look better with dark interiors and vice-versa.

 

[L48]

For your item # 2
My trim tag is 13L. I'm the third owner, and know that the car was silver when purchased new in MD.

Thanks. I just wanted to make sure 13 and 13L were the same thing. The page fl_rider refers shows silver exterior as 13, not 13L.

The fact that it has been painted red twice is making this harder. If the car was ever actually silver I will find silver somewhere on this car. Based on the current condition of the car I can't believe someone would have gone through the trouble of covering every last inch of the silver paint. I have looked under trim pieces, bottoms of door hinges, crevices on the inside bottom of the door, where the car has been nicked, under the hood, around the headlights, anyplace I can think of. No sign of silver paint anywhere.

I could see it if someone was trying to restore the car back to original for show, but this is a plain L48 - nothing special (other than it is a Corvette). If someone painted it red because they did not like silver, there would be no reason to go to this length to hide the silver.

Maybe there are some clues under the carpet or under the front window moldings.

I can't imagine the trim tag is not original, though stranger things have happened.

 

[fl_rider]

My trim tag has the L suffix also.
If it had been two tone L would have stood for the lower color.
Single color still has the L suffix.

Chris B

 

[Dave Z]

My trim tag has the L suffix also.
If it had been two tone L would have stood for the lower color.
Single color still has the L suffix.

Chris B

Hmmmm...Interesting.

 

[JohnZ]

I am trying to better identify my 1975 Corvette.

1) I want to confirm the block is in fact numbers matching. Here is the numbers on the block (on the machine surface just in front of the head on the passenger side): 15S409424 V1203CHB. What part of this should match the VIN?

2) The trim tag in the door jam indicates the interior is 14V and the trim is 13L. According to the reference on this site 13 is silver. My car is dark red (see avatar). I have spent a good bit of time looking for the silver paint underneath the red but find no sign of that anywhere. It has been painted alright - repainted the same color red. The interior was originally silver and I can see the silver peeking through on some of the black panels.

Does anyone else have a 1975 car with 13L code and what color is it? Any other insight on this would be appreciated.

1. If your VIN is 1Z67J5S409424 and it's an L-48 automatic, the pad stamping appears to be original to the car.

2. 13L paint is silver - the "L" (lower color) indicates a solid-color car; if it was a two-tone, the other color would also be shown with a "U" (upper color).

 

[craig32]

L48, What color is your trim tag? Is it red also, instead of chrome? They generally don't get taken off to paint, or masked off. It should also have the last 6 digits of your VIN on it, as well as your engine. It is not uncommon for a different color repaint to be 'complete.' They generally take the hood and doors off, especially for a different color. Being a St. Louis car, it would have had lacquer (instead of enamel at Bowling Green) and fiberglass stripper works well on it instead of sanding. If your trim tag was masked or painted over, (both times) it will be silver paint underneath. Also, under the door panels could be some original paint. Your car sounds like mine, 2nd owner repainted it very good, 3rd owner let it fall into disrepair.
You mentioned in another thread that you put brake fluid in it to drive it home, what kind did you use? Good luck in your search.

Craig

 

[L48]

The tag is still silver (apparently stainless) - there is clear evidence it was masked off (a slight bit of red paint on the tag itself). I'll try that later.

As a last resort I may remove one of those rivets and look under there - not ready to do that yet.

The brake fluid was DOT 3 fluid from Western Auto. I had used fluid out of this container before without any problems.

 

[craig32]

I made the same mistake with DOT 3 fluid. It is supposed to have silicone DOT 5 fluid and they don't mix, apparently it will gum up eventually. My front chamber was almost completely empty, and I didn't notice the difference. I don't know as it causes damage to any parts but clogs the lines. I need to have mine flushed and replaced sometime soon. Bleeding the brakes helped my car, the back calipers have two bleeders. Hope it doesn't cause either of us a problem. . . :confused

 

[L48]

I made the same mistake with DOT 3 fluid. It is supposed to have silicone DOT 5 fluid and they don't mix, apparently it will gum up eventually.

My inexperience as a Vette owner is showing. Thanks for the warning. As I mentioned before the brakes were already messed up when I got the car - maybe this is part of the problem. Based on all the other problems I would not be surprised if the prior owner also put incorrect brake fluid in the car. Looks like a flush is the first order of business here.

 

[craig32]

My inexperience as a Vette owner is showing.

Same here, my day 1 mistake also. It's been that way for almost a year (just recently found out it would cause problems) nothing yet. After I bled them a second time, I actually had decent brakes. Funny thing, my Harley has always had DOT 5 in it and I'm having problems with it. Maybe it isn't worth the extra money.
So does your trim tag, engine stamp and VIN all agree? My previous owner put in a Jasper engine, seems to work pretty well, so far. . .

Craig

 

[JohnZ]

L48, What color is your trim tag? Is it red also, instead of chrome? They generally don't get taken off to paint, or masked off. It should also have the last 6 digits of your VIN on it, as well as your engine. Craig

No VIN on the trim tag - just the body build date code, paint and trim codes.

 

[lucky76]

Dot3

My inexperience as a Vette owner is showing. Thanks for the warning. As I mentioned before the brakes were already messed up when I got the car - maybe this is part of the problem. Based on all the other problems I would not be surprised if the prior owner also put incorrect brake fluid in the car. Looks like a flush is the first order of business here.

I have a 76 but I think the Service Manual should be the same. It says
Every 6 months or 7,500 miles -- Check brake fluid level in each reservoir and maintain 1/4" below lowest edge of each filler opening with Delco Supreme No. 11 or DOT-3 hydraulic brake fluid.
I think DOT-3 is correct for your car.

 

[craig32]

That's interesting, my 1981 manual says 'Use Delco Supreme No. 11 Hydraulic Brake Fluid or equivalent.' Nothing about DOT 3 or DOT 5. Anyone else want to weigh in here? All I know is DOT 3 is yellowish and DOT 5 is purple, and they don't mix - if the reservoir is completely empty (which mine was) your odds are 50/50 of getting it right :confused

Craig

 

[L48]

According to the local parts store DOT3 or DOT 4 are acceptable for the 75. The fluid that was there appeared like DOT3 - maybe a little dirty but no hint of purple.
I was waiting for the owners manual I recently bought to be delivered to confirm it.

BTW it appears my proportioning valve is leaking fluid - I am guessing this is the main culprit of my braking problems.

 

[JohnZ]

That's interesting, my 1981 manual says 'Use Delco Supreme No. 11 Hydraulic Brake Fluid or equivalent.' Nothing about DOT 3 or DOT 5. Anyone else want to weigh in here? All I know is DOT 3 is yellowish and DOT 5 is purple, and they don't mix - if the reservoir is completely empty (which mine was) your odds are 50/50 of getting it right :confused

Craig

GM wants you to buy their brake fluid, so they give you the label name, assuming most people have no idea what DOT codes mean. DOT3 and 4 are completely compatible - the only difference is that DOT4 has a slightly higher wet and dry boiling point, and costs a bit more. Every production car on the planet uses DOT3 for factory fill (except the Viper, which uses DOT4 - I changed that at the request of the owners when I was the Plant Manager). DOT5 silicone fluid has NEVER been factory fill for any production car, and is totally incompatible with glycol-based DOT3/4 fluids.

If you're not sure which fluid you have, take a 2 or 3-ounce sample from the master cylinder reservoir, put it in a glass jar, add an equal amount of water, cap it, and shake it up real well. Let it sit on the bench and settle out. If it forms two distinct layers, it's DOT5 silicone; if it simply becomes a homogeneous mixture with no distinct layering, it's DOT3/4.

 

[craig32]

John Z, thanks for the heads up and the experiment. Not only is my brake fluid the color of Labatt's, but it doesn't seperate from water as you said. The DOT 5 (factory fill for my Harley-Davidson, BTW) DID seperate, so no problem in my system.
L48, sorry for the scare - I was passing on the word of others here. That would probably explain why my brakes are working. . .

Craig

 

[Tritium007]

I haven't had any brake problems yet but I have heard that C3's are notorious for requiring frequent bleeding resulting from vapor problems due to both high temp conditions (low flash point fluid) and sytem configuration (too many high points). Does flushing out the standard DOT 3/4 fluid and replacing with a synthetic such as DOT 5 improve this condition?

Mike

 

[JohnZ]

I haven't had any brake problems yet but I have heard that C3's are notorious for requiring frequent bleeding resulting from vapor problems due to both high temp conditions (low flash point fluid) and sytem configuration (too many high points). Does flushing out the standard DOT 3/4 fluid and replacing with a synthetic such as DOT 5 improve this condition?

Mike

No, it doesn't, and C3's aren't any more susceptible to needing frequent bleeding than other cars, unless they have leaks due to poor maintenance or brake rotors that are improperly replaced without checking for lateral runout. It's FAR more difficult to bleed a C2 or C3 brake system using DOT5 silicone fluid than it is with glycol-based DOT3 or 4 fluid. Flushing and bleeding a C2/C3 brake system at home is a ten-minute one-person job with a Motive Products Power bleeder.