My Anti-Freeze is Leaking

[Dave L.]

Also check the thermostat housing area and where the heater hose connects to the fitting on front of the intake.

Dave

 

[WayneLBurnham]

First, looks like you have multiple leaks

Can't tell good from the pic, but it also looks like you have a stain coming down from the forward (or passenger) side water neck bolt too.

Now, is the leak coming from the line where the intake meets the main block? It almost looks like it's coming out of the block itself...

I agree, try tightening the bolts first.

If it is the intake, this is a chance to swap to a better flowing, lighter weight intake if you wish, for $100-225. For even a little more adventure, once the intake's off, you're halfway to the cam!
For another couple hundred or less, a cam matched to your intake - stock or new - could come close to giving you a 50% horsepower increase by itself on a mid '70's stock engine.

Just some options, because the intake pull, clean and refit should take four hours. The first time I did this one ended up including the second and lasted over four days[/i], thanks to a never-drying mislabelled sealant from NAPA.

You can usually leave the carb on the intake when pulling it. You use an open end wrench on the center bolts anyhow.

Mark your distributor's position well - where the rotor is pointing - and beware of other's earlier marks on there. (I will say no more on that to save my fragile ego.) Your camera is a great aid there.

Test the sealant you pick before you use it. We used to always do this but I got stupid and trustful.

Other than that, it's straightforward. You may want to change your intake bolts to a set of 12 point 3/8" hardened numbers.

Oh! One thing! Do NOT use the little cheesy front and rear seals they give you in the intake gasket set! Those are leak-o-matics!
Instead, you put one, nice, continuous bead of your sealant (if you use a silicone rubber (AKA "RTV" or "silite") sealant rather than a thin gasket dressing. Either way - for the front and especially rear use a nice thick bead of silite - I think one of the vette manuals even recommends that. Those front and rear seals they came with and they include are very difficult to position correctly, to put the correct amount of silite around in the right places and are just designed for factory installation or rebuilding an engine on a stand.

 

[Stallion]

Hmmm...so you guys are pretty sure it's the intake, then? I will get my hands on a torque wrench and tighten it. How do I know the torque for those bolts? Where can I find those specs?

Thanks and I hope this isn't too serious!

TR

 

[Bob Chadwick]

Sears is a good source for all your tools.

 

[Stallion]

Okay, I'm sure my dad has a torque wrench. If not, I'll go out and get one. But how much torque will I know I need to put on this specific bolt? Where do you get all these specs?

Thanks!

TR

 

[Bob Chadwick]

I haven't gone hear yet but I suppose they would be in the shop manual.

 

[Dave L.]

TR - After studying that picture and comparing to my own car,I would tighten the intake bolts like the others said(torqued to specs and following the proper pattern for tightening) and also replace the thermosat and gasket. Those are easy repairs to do. We could talk you through it. I am leaning towards a leaking thermostat housing gasket or possibly a cracked(housing). Once you have it off it could be thoroughly inspected. Putting a new thermostat and gasket and draining and flushing the anti-freeze would be one of the first things I would do to a car I just purchased anyway. Time to get a GOOD shop manual and start reading up. It's a piece of cake,I know you could do it!!

Dave

p.s. I'd also like to add that it is NOT a serious problem but one you will want to look into for sure. My car developed a slight leak similar to yours last fall and I am just now getting around to fixing it!!

 

[68Roadster]

Torques

TR,
The manuals I have say 30 ft. lbs for the Intake manifold bolts and 20 ft. lbs for the water neck the upper radiator hose goes into.

Go to any auto store and pick up a Clymer or Chilton for your car. It will probably be a general one, 63-82 or 70-82 but at least it has torque values (along with the sealant for the bolts if you pull them and clean them up). If they don't have one, Amazon.com should be able to hook you up.

Next go to www. volvette.com and order an assembly manual for 16.95. These things are invaluable. It won't show you much on the engine itself since it is brought to the line as an assembly. It will however show you all the accessories/piece parts that hook to the basic engine.

The water neck replacement is a breeze, remove, scrape off old gasket, replace thermostat (note which way it is mounted), install sealant and new gasket and torque.

Have fun.....if it's snowing, you might as well work on the Vette.
How did you make out on the guages that weren't working??

Cee

 

[Stallion]

I'm over at volvette.com and looking for that manual. I've been asking around for where to get them, and I guess all '78 Shop and Assembly manuals are the same? Just different people/companies sell them? There's one "official" type copy?

This doesn't sound out of the realm of TR-fixable and I think I can manage this. With the manuals and one of those books (Clymer or Chilton -- still gotta go to Amazon to look for them) I'm sure I'll be fine.

Initially, though, I'll find a torque wrench to make sure that it's not just loose bolts.

I'm glad you guys don't think this is the water pump, because I'm not sure if I'm ready to change the pump. I'm sure if necessary I could probably do it, though.

Thanks!

TR

 

[Stallion]

Along with an Assembly manual, I want to purchase a Shop Manual for my '78, but I'm not sure if volvettes.com has what I'm looking for.

It has a "66-82 SHOP MANUAL EA" but is this what I want? I thought shop manuals were for specific years. Like, I would get a '78 Shop manual. Or am I wrong? Because this book seems to be a compilation. Where would I get the shop manual for my '78?

Thanks!

TR

 

[68Roadster]

I'd go for replacing the water neck gasket first and torque the intake second. Give it a while and see if it subsides. It has that greenish tint to it, think Wayne nailed it...coming from the neck bolt.

Everybody sells the assembly manuals, just check 'em all to get the best price.

Lotsa luck!

 

[Stallion]

You wouldn't happen to have a picture of this water neck gasket, would you? I don't think I specifically know what you're talking about. Where is this? Maybe where the water pump is met?

Thanks!

TR

 

[68Roadster]

Manuals

Ecklers has the '78 Shop/Service Manuals but they are 90.00 for the set.

Might try all the other shops....Last Detail, Paragon, Helm Incorp or look on e-bay or swap meets. Should be able to find them cheaper, I'll keep a look out.

The Assembly Manual is good because it also gives torques on most things (at least my 68 does), just doesn't cover engine specifics. Keep in mind, this book shows how a Corvette is assembled on the factory floor.

Thats another thing. If you ever get anywhere near Bowling Green, KY, you would not be disappointed if you took the tour of the plant. I went in 97 when the new body style came out and it was awesome!

Have fun!

 

[Stallion]

Thanks! I will also look around to find the Shop Manual. Until then I'll order the Assembly manual just so I have it ASAP and then when I run into the Shop manual I'll order that.

Thanks!

TR

 

[78SilvAnniv]

TR- water neck gasket

TR, the water neck gasket looks like this:

<O> (sort of...)

There are holes in the points for the bolts. This gasket is for the 'neck' that is located at the front of your block, and connects your upper radiator hose to your radiator.
The thermostat is housed under the neck.
Heidi

 

[68Roadster]

TR,
These pictures show where the water neck is and the thermostat when it's in the intake manifold.
The gasket looks just like the manifold boss, one big hole with two bolt holes, one on each side.

If the pictures won't post, I'll e-mail them.

 

[WayneLBurnham]

Oh you would MUCH sooner replace the water pump than the intake

Popping off the thermostat housing and changing that thermostat and upper hose isn't a bad idea anyhow. Make sure you get one of the high flow thermostats - a gasket will come with it. I'd stick with the 195 or 210 thermostat, whatever is specified, due to your cold climate. In the summer, you may wish to change to a 165 if you have heating problems. These things typically have awesome radiators and the engines from the mid years don't tax them very much. Once I purged mine good AND got the heater core reconnected (lots of reserve cooling there)and richened the mixture a little, I can't ever get it to temperature, although I did last summer when I held it over 95 or so for 20-30 minutes, which would kill the engine now with no overdrive and the 3.73's.

Resist the temptation to get one of those nice chromed autoparts store water necks. I went through two of them in a few weeks last summer before I got a good old fashioned IRON one. The cheapies at the parts houses aren't aluminum but some zinc or other alloy and, O-Ring or not, they WARP. Should you want to do that, get a chrome plated steel, aluminum or billet aluminum one.

As for books, here's what I have in order of DECREASING usefullness for what I've needed so far:

• Corvette 1966-82 (sic) Shop Manual (MBI Publishing)
• Corvette Repair Manual, 1968-1982, #28500 (Chilton)
• Chevy Corvette 1968-1982 Haynes Repair Manual, #24040
• Corvette 1975 Supplement Shop Manual (Assume Chevrolet Service Press - I don't see it right here in the pile)
• 1975 Chevrolet Service and Overhaul Manual Supplement (Chevrolet Service Press)
• Corvette Assembly Instruction Manual (in Corvette Central 3 Ring Binder)
• Chilton's Automotive Repair Manual 1972-1979 (the big maroon book)
• How To Restore and Modify Your Corvette 1968-1982
• Corvette America Master Catalog (tons of great diagrams)
• Corvette Central, Ecklers, Mid America, VPB Catalogs, etc. (other great diagrams and parts lists)
• A half dozen or more various specialty books and pamplets on systems and specialties (Air Conditioning Strategies, Leak Strategies, 2001 Corvette Black Book, etc.)
• Numerous printouts of products (Gear Vendors, Tom's Differentials, Topics from here, etc.) (I need to put these in a binder.)
  [/list=a]
  
  Get those books and catalogs as you can find them - as many as you can find. Every parts distributor (Corvette Central and Eckler's especially) has a huge library page. I bought about 60% of my $200-300 vette library from those. Others I went to book stores for - your best first source. These are often on sale at 2/3'rds or less the cost of them from more automotive sources. Half Price and used book stores are also good hit-and-miss spots if you have any nearby. (I need to go do that myself.)
  
  The specific ones go into incredible detail. The GM Shop Manuals give you enough information to build a new car, and make you jealous for all the specialty shop tools and jigs.
  
  The generalist ones like Chiltons, Haynes and Clymers (forgot about that one - I need to get it) often give you a different procedure on a particular repair that is much easier and gets you away from excessive Corvette Perfectionist Guild orthodoxy for basic repairs. (Never forget you have a CHEVY with a CHEVY engine and a CHEVY transmission. That makes it more universal, cheaper and gives you greater options, including power and reliability ones not available when your car was made.)
  
  I also subscribe to four of the five Vette magazines I know of:
  the first two full size: Corvette Fever and Vette and the Corvette and Chevy Trader and the little but super useful Vette Views. There's a new one out I haven't signed up for yet, but I will. I also get about ten other car rags, including Car Craft, Hot Rod, Hemmings, two Chevy somethings, two Custom and Rod somethings and a Mopar one, and I don't throw or give away any of them.
  
  Unlike the car BOOKS though, be careful of how many subscriptions you get. Mine eat up better than a day's OT pay every year.
  
  Of course, you don't need a single reference book to do a single repair, but it's a hell of a lot easier if you have an excess of sources of info rather than a lack of.

 

[ratdog]

Welcome to the world of owning a Corvette. Everytime you drive it, expect to have repairs totaling no less than 250$. Sounds like you have no mechanical abilities, so be prepared to pay high hourly labor rates!!! Have fun and enjoy your endless money pit we like to call America's sports car---------------------By the way, I have 2 of those pieces of crap, don't ever drive them more than 100 miles a year, mainly because they are unreliable and shaky at best (must be me though)

 

[Stallion]

"Corvette 1966-82 (sic) Shop Manual (MBI Publishing)"

This is the one I'm looking for. I've found the Assembly Manual, but I can't find this one. Where did you get it?

68Roadster is sending me pictures of what this water neck gasket looks like and then hopefully I'll be able to pin-point it in my Vette and analyze if that's what I need to change. So it's either that or the intake?

Thanks!

TR

 

[ratdog]

Dude, listen!!!! Any manual that shows work on a small block chevy will do. The thermostat housing and gaskets are the same configuration. Thats the beauty of chevys, one size fits all(so to speak). A thermostat gasket will cost you 1$, the pain and toll mentally of putting it in is priceless!!!!!