This is a repost from the Intro section. They said I should post this here.

My dad surprised me with a great graduation present. His 1974 Coupe with the L82 engine, electric windows, air conditioniong, power brakes, automatic transmission, tilt-telescopic steering column and power steering.

I'm the third owner of the car, my dad being the second. He's had the car since 1981. It has about 116k miles, and is mostly original.

The good news:
The engine has never been rebuilt and still cranks quickly and doesn't smoke.
Interior was recently replaced, so all of the upholstery is in great shape.

The bad news:
There is some rust on the car from when my dad left it outside for a year or two, but it has been garage kept for the past 20 years or so.
The transmission has a leak, and the rear differential leaks, but both still work.
It has some electrical and vacuum system issues.
It's been sitting up for 8 years. It's been stuck in the garage since Hurricane Katrina (2005), but it has been started every month or two.
The T-Top and rear window leaks.
Front brakes are leaking, but we have a lifetime warranty through Lone-Star Caliper, so I just have to pay shipping to get them rebuilt again.

I plan on keeping it in the garage from now on. Over the weekend I gave it some much needed TLC and changed the oil.

I'm on the MS Gulf Coast. Temperatures get down to maybe 25F and up to 105F. I ended up putting in Pennzoil Platinum 10W30 Synthetic, which is the same brand I put in my daily driver car. I read up on the flat rod lifters on the cam needing high zinc (ZDDP) for correct lubrication, so I also added a bottle of Lucas Break-In fluid. Also put in a K&N Oil Filter, also same as what I put on my daily driver. There is no catalytic converter in this year of car, so no worries about the high ZDDP killing it.

Replaced the windshield wipers. Is it just me, or are they hard to find? There wasn't much of a selection.

Also replaced the power steering pump belt as it was disintegrating.

So overall, how am I doing and what do you guys/gals recommend?

I'll have some more posts coming soon!

 

Here is the only picture I have of her so far. It was taken about a month ago. I had just come home for a few days for spring break and saw my dad washing her. Crazily enough, we also took a ride down the road. First time she had been driven in about 8 years.

Attachment 48376232

I just ordered a new heater core and a new master cylinder.

I had a $50 off of $100 or more coupon from Advanced Auto Parts, so...

Heater Core: ToughOne or Ready-Aire - Part #: 399081
Master Cylinder: WagnerBrake Master Cylinder - Part #: MC89160

I also got new speakers for the dash... not that the original sounded terrible when the car was new and not that age hasn't taken a toll on those great quality speakers...

I found this guide for the heater core.
Again, any recommendations, tips, tricks, or other things to check?

 

Welcome to the forum. I can't help much wIth your year model. But it sounds like you're heading in the right direction. Take your time and do not try to do everything at one time. She looks like very nice car. Like the paint job. We all like pictures here. Try to post more. And congratulations.

 

Just a suggestion...

Don't get in too much of a hurry to change everything. The original parts that were put into the car were much better quality than anything you can find today. If an accessory item (like, starter, alternator, etc) isn't working like it should....REBUILD IT...for much less money than a "new" piece of aftermarket junk will cost you. Rebuild parts are readily available at almost all auto parts stores--but they would much rather sell you a whole starter than a new starter solenoid and a set of brushes for the starter.

Learn about the car and what everything does. If you replace "working" parts...like suspension or brake parts...spend a little extra and buy the best parts available. NOT necessarily the most expensive; but some manufacturers are better than others. This Forum can help you decide what is best.

Buy a copy of the A.I.M. (Assembly Instruction Manual) for 1974; it will be invaluable in helping you to take things apart on the car...and get them back together correctly. Also buy a copy of the Chevrolet Chassis Service Manual; it shows all the detail about how the car's various systems operate and how electrical and vacuum items function.

Don't get stoked on bumping up the horsepower until you really have had the car a while and are sure what you want to do with the car. As it sits, it is almost completely original. If you start "modding" the car, it's value will drop----rapidly. Just make sure of what you want to do, and why, before you 'jump'.

Enjoy it and BE SAFE. If YOU do something stupid with the car and get hurt...or worse, your Dad will never forgive himself for giving it to you. He apparently trusts you enough to think you will be responsible with a Corvette 'at the ready'. Don't let him down...

 

Hi r,
Welcome!
New, old, Corvette for you! NICE!
I agree with 7T1 about the 2 manuals to buy. They will be a big help you as you work on your car.
I also agree with him that you should be careful about replacing things that are still working since so many new or reproduction parts turn out to be a disappointment.
It's a old car and buying lots of new parts just make it less of an old car. See if after a while you find you like the car for what it is. I'm not saying to not make it SAFE and FUN to drive, but no matter what you do, you can't make it act like a new car... and for many people THAT'S the charm.
Good Luck!
Regards,
Alan

 

Welcome and congrats on the new ride. Enjoy it and have fun, do little bits at a time so you can drive and work things out.

 

Sounds like I'm heading in the right direction.

The heater core is being replaced because it leaks, and with a brand new interior, I don't want it leaking all over the carpet.

The master cylinder is another part that is leaking... but just a tiny bit... but more importantly, it's not holding pressure when I push down.

I don't intend to race the car at all. No auto cross, no drag racing, just a good around town car. I want to keep the car as close to stock as possible. The original stereo is already gone... was gone a long time before I got the car. I would like to get the center console with the square cutout for a stereo so it doesn't look so bad, but that's for the future... along with a newer radio without a cassette deck and analog radio tuning.

I want to overhaul the vacuum system just so everything run by it works properly (think headlights). The vacuum solenoids for the headlights aren't that old. I think my dad said he had those replaced just before it sat in the garage. The car has a bad vacuum leak somewhere though. It doesn't generate enough vacuum to lift the headlights on its own.

There are some electrical problems with the car that I would like to get sorted out. I'm not only interested in keeping it stock, but I would like to get everything working. I'm sweat the little details. The alarm system no longer works. It could be a fuse, but it could also be a number of things... The switch is one part I'm looking at that could be broken. It was hard to turn and the key got stuck in it when I tried it the other day... WD-40 helped free it, but still no alarm. Apparently the windshield washer pump has never worked. The climate control stopped working since it's been sitting too.

I did get the Haynes work book, but it seemed very... scripted? Like it wasn't really made for the Corvette. I'll get those two books you guys recommended. The internet is a wonderful place to get information, but it's a PITA to keep my laptop out by the car while I'm working on it without ruining it... plus not everything is true on the internet. I agree with the book philosophy.

Here's a bit more about me. I'm a computer engineer (basically electrical engineer, minus high power transmission and electromagnetics, plus programming and embedded electronics). I have done wiring and electronics well before college, so I'm better than your average Joe at it, and I know how to debug stuff pretty well. I'm also pretty mechanically inclined. I do all my own work on my Mazda3 that I drive daily, and I have modded that car kind of heavily. Removed the intake to remove some butterfly flaps that helped create a 'vortex' inside the engine. Gained 5HP by doing that. New engine mounts after the stock ones broke. Brakes, struts, you name it, I've done it. Still drives like new.

Back to my plans. I want to keep it as close to stock as possible. That's where the value is, and that's how Chevrolet wanted the car to be. I want to fix all the fluid leaks... easier said than done. The engine doesn't leak per say, but there is all sorts of funk built up on the engine that came from somewhere... could be all transmission fluid, could be engine oil. I'm not sure. I'm going to get some cans of Gunk and either the hose or the pressure washer and go at it from underneath. Clean the slate and start fresh.

My dad took off the front calipers and had them sent off to get fixed. The rear two were recently fixed. One just a few months ago, the other a few years ago. So the calipers should be good for a while. As long as they are used often, I think they're good. Sitting just ruins them.

As far as the near future (1 month) plans:

• Fix Transmission Leak
• Fix Rear Differnetial Leak
• Replace Heater Core
• Install new dash speakers
• Replace Master Cylinder
• Reinstall front calipers
• Fix rear windshield leak
• Replace weather stripping
• Replace oil pressure sender

Thanks for all the information so far!

 

Yep. Haynes manuals suck....if you want to actually work on something. They are like a Cliff's Notes for auto repair manuals; they give you a good idea of where to work and what needs to be done...but they don't give enough detailed info to actually accomplish anything.

Work thru your problems one at a time, so you can focus your efforts. And, stay with it until you get it to work as it should (not necessarily as you want it to...sorry). Get a game plan for one project together, then come to the Forum and ask this 'crowd' to review your plan and offer constructive advice/criticism. Remember, many on this Forum have already done what you are doing and KNOW the pitfalls that my be in your path. Hear what is said by all who contribute; then select what you think is the best advice and forge ahead. If you hit a stumbling block, ask for some help.

Start with projects that are SAFETY related: brakes, suspension, lighting, etc. Go to OPERATIONAL projects next. Do andy COSMETIC / APPEARANCE projects last. I know you want to make it look PURTY...but fix the important stuff FIRST.

Have fun, work safe, and GOOD LUCK!!!

P.S. Learn how to diagnose vacuum system problems and how to easily and quickly test the vacuum components and lines. MOST vacuum problems are simple fixes and DON"T require purchase of many components. But, testing a vacuum system may be 'strategically' similar to electrical problem diagnosis; but the tools and methods are quite different. You can't test electrical and hydraulic problems with the same tools or with the same methods. Same with vacuum. It is a different system and requires different tools and logic.

 

I agree with the above suggestions to first and foremost make the car safe when driving. Then, just drive the car and listen. It will tell you what it wants next.

DC

 

Nice surprise from dad!!!!!! Best of luck w it.

 

Great dad!!!

Like Lt1 said, do the operational stuff first than cosmetic the last. That is exactly what I've done but new paint is still in the works.

I ran into a fello C3 owner at a gas station with beautiful bonnet yellow paint and perfectly restored interior. Car looked beautiful but he told me he has engine issues. He bought a crate motor and it had LOUD (hammer tapping) lifter noise, engine smoking from both valve covers and his exhaust sound at 850rpm sounded like a go cart ( i mean it was literally making "putt" "putt" sound) and told me his getting 6 MPG on a 350 SBC. His engine was running so rich, my eyes were watering and got a serious headache while I did a good thing and checked the timing for him since he never timed his car.

I rather have a sound driving machine than something that looks great but runs like crap. If you have the money, you can have the best of the both worlds.

 

Here's a few things to help you get started:
74 schematic:
http://www.vetteprojects.com/bmv/mis...tte%201974.pdf

Vacuum troubleshooting:
http://www.corvette-101.com/vacuum.htm#top

Here's the alarm schematic:

and here's where the parts are:


Trico #16-2 blades are low profile and fit under the hood.

Enjoy your new ride,
Pete.

 

Congrats, looks like you have a nice solid Vette to start with

 

Well I've worked pretty hard the past two days. Still waiting on brake calipers to ship back and it was the wrong heater core, so I ordered on from corvettecentral.com.

Since I had the dash all apart, I wanted to inspect everything, and I found a lot of stuff that worries me.

Mice / rats have found the car. I found a vacuum line that had been straight chewed through, and they got to some of the wiring in the center console by the shifter and AC.



Worse... my dad got to the wiring.



For the rat wiring, I wanted to put heat shrink on it rather than electrical tape. E-tape just gets sticky and doesn't perform its job after a number of years. To do this, I had to splice the wire. If it was just nibbled on with a bit of copper showing, I slipped some heat shrink over. For the bad stuff, I put in a butt connectors that heat shrink down to seal it. For the really big stuff, I soldered it.



Also, digging into stuff, I wanted to see what was working and what wasn't working. I found the fresh air vent (I think) was broken.
I ended up drilling a hole where the metal stud used to be, tapping it with an 8-32 tap, and putting a bolt and a nyloc nut. Probably better than the factory one. Now it works properly. I also added some lubricant to all the hinging points.



At the end of the day... I still didn't have a heater core, so I ended up doing my magic with the wiring. Before it just fell out of the car when I removed the dash pieces. Much better!

Not pictured, but I also redid the stereo wiring that my teenage dad did back in the '80s. Part of it was the aluminum foil over that fuse. It also had an inline fuse, which was also surrounded with aluminum foil. Now it has it's proper 2A fuse and is connected to the original stereo wire.

Now onto the problems...

The seat belt safety switch / backup light switch was removed from the shifter. I had no idea why, so I bolted it back on. Now upon checking out everything, whenever I put the car in drive, the battery current gauge goes to around -40A and the lights dim. No fuse blowing yet, no smoke, but I don't want to try it for long just in case whatever is shoring isn't powered.



What I don't know is what is shorting. The electrical diagram kind of sucks for that switch. There is 4 wires going to the switch, but the schematic only shows 2. The pink and green wires are small guage, and the purple wires are heavy gauge. Seeing that it does it once I put it into drive, and not park or reverse, then I believe it's the seat-belt portion of the circuit, but I don't know how it's supposed to work.

This apparently happened before my dad owned the car in 1981. Maybe a common failure of these cars?

I can't think of anything else right now and my battery is about to die in my laptop. I'm getting married tomorrow (woo!) and will be on honeymoon for the next week, but I need to get this short fixed before I leave to go back to work so my dad can drive it if he needs to.

 

Very nice to keep it in the family thanks to Dad. Best of luck with it.

 

welcome to the forum, and the hobby. you have gotten some excellent advice. the only thing i may take a little exception to is your oil and additive choice. i am not a fan of additives, so i think you may be better off with an oil with the zinc already in it. there are plenty of options.

 

I lol'd

 

It could be worse.. my 74 was a disaster wiring had been chewed though it spots by mice but they didn't stop there... nests under both seats made of carpet and insulation... I just wish they would have completely chewed away the 1980s RadioShack siren installed with a doorbell button and lamp cord for a horn .... all because the previous owner had put the horn button assy back together all wrong.. I had all kinds of wiring blunders to fix... the window switch harness was butchered and lengthened with more lamp cord for some reason..... I did manage to find an old birthday card with 20 bucks in it and about $6 in change under the seats

 

The neutral safety switch is two switches in one housing.
When you turn the key to START you send 12 volts to the NSS on the purple/white wire,
if the NSS is positioned correctly in the console and the shifter is in P or N the 12 volts go through the switch and on to the starter on the purple wire.

The other part of the NSS is the reverse light switch.
Pink brings power to the switch and when the shifter is in R the power goes to the bulbs on the green wire.


Disconnect the pink and green and see if the battery gauge problem goes away.

On all 74 models GM made a seat belt module that will not let the car start until the seat belts were fastened, that's another can of worm to deal with.

 

I'll check it out. I know the green and pink wires are easy to disconnect, so that shouldn't be a problem. I can also check the purple wires to see if they're working properly.

Now it kind of sounds like the shifter cable is shorting something out instead of the switch because nothing should happen when I put it into drive. I know for a fact that the oil pressure sender was grounding out to the shifter cable. No idea if something else is though.