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Got the general fluid filters replaced. Dropped the tank and cleaned it out and put in a new sending unit. Primed it and the car started right up after sitting for almost 30 years. I noticed a coolant leak at the front of the intake just below the thermostat debacle and its definately not mixing with the oil but certainly explains the intake gasket I found in the trunk that never got gotten. How big of a PITA is it to do on these cars with all the hoses and crap all over the top? Better to let a garage do it or pretty straight forward? Ive got the service man and can use that to guide but figured at least one of you guys have done this and it if it was a nightmare Ill prolly farm it out to save time? Thanks Pat
I wouldn't farm it out because of the vacuum hoses and wires, the chances of finding someone that would do it as well as you would on your classic car are very slim. Take pictures from several angles. Tag every hose to where it goes, replace the vacuum hoses on the rebound. Replace the fuel filter in the carb, maybe add one just before the fuel pump.
Once everything is out of the way it is like replacing an old school manifold. I'm guessing 6-8 hours to do it nicely. Probably could do it in 2-3 if wasn't a classic worth making it right.
Be prepared for excessive pitting on the manifold at the coolant passages that may need some reconstruction with JB Weld or the like.
You might as well try to find the vacuum hoses ahead of tie. When I did my Wife's Riviera I had to order them on line because all of the lines they have at the parts stores are metric and dont quite fit If they have never been replaced now is the tie to do it. Like the others have said unless you have a mechanic that actually likes to work on classics I would do it yourself. Lots of old brittle plastic fittings that can break if you try to rush it.
How do you know its not the t-stat housing leaking?
When trouble shooting always look to the simple easy things first. Human nature is apparently to do the opposite.
Id perform a pressure test on the cooling system before pulling the intake. A pressure test will show you where the leak is.
The coolant is likely very acidic if its 30+ years old.
It should be changed about every 5 years depending on what you get for a voltage reading or PH test. Probably way past its time to flush and refill.
Install a new 195° stat, premixed coolant, and use the blue flepro gasket. Make sure the stat housing is flat. Make it flat if its not.
Apply a thin coating of RTV to the gasket and the upper portion of the the housing bolts. The bolts go into the coolant passage and will weep up through the threads.
Give this attachment a read.
This as a live document for a car like yours that sounds like if fits one of the scenarios within.
I have ta make one of these for timing and carb tuning too....
The horizontal point would leak oil. Coolant there could be traveling from the thermostat housing, upper hose or the intake from where it meets the head on an angle. The intake leaks on the angled mating surface usually leave a crusty buildup. If it is the intake the concern is coolant leaking into the crankcase but not being seen.
Aluminum next to steel = galvanic corrosion. Some 307 intakes back in the 81/82/83 years are cast iron, but many are aluminum.
307 leaks at the corners with aluminum manifolds is not uncommon. What has likely happened is the steel gasket "turkey tray" was used, either factory or the fel-pro aftermarket replacement, and the corrosion got to the gasket around the water port(s). The aluminum sometimes pits and allows seepage. It won't get any better by itself. The peanut port roller cam engines had it the worst from what I've seen over the years for whatever reason.
Either way, it's a HUGE pita to disconnect all that junk and the vacuum lines. It's like working on a 350 otherwise, but with all the emissions lines/stuff you have to deal with. 5/32 and 7/32 are many of the vacuum tubing you'll need to contend with. Some 3/8 for a few carb hoses, too. Might as well get them all while you're doing it. After you're done, you'll never want to do it again.
No leak at the thermostat. It’s just above and to the right of the oil sending unit. Safe to assume I need to pull the intake? I see nothing in the oil but it’s definitely dripping down the left front of the block.
If there's pitting on the aluminum intake and the head surface is still good, I have cleaned the intake, filled the pits with JB Weld, sanded it down flat, and regasketed on an 87 Salon I owned before. Happened about a month after I bought it. Never had an issue with corner leaks again after that for as long as I owned that car. It leaked right where yours is, but there were also some pits forming in the back driver side as well. JB Welded those pits too as a pre-emptive strike. My suspicion is the P.O. didn't do proper maintenance around coolant flushes/changeouts.
Of course, I'm not advocating for JB Weld repair, but it worked for me. Much cheaper and faster than having someone alumi-weld it.
If they have never been replaced now is the tie to do it. Like the others have said unless you have a mechanic that actually likes to work on classics I would do it yourself. Lots of old brittle plastic fittings that can break if you try to rush it.
