Snapped thermostat-housing bolts

[mjlan]

The sensor in the green circle looks like a vacuum switch (triggered by coolant temp) but the top hose nipple is broken off...

 

[mjlan]

I found a picture of my '72 2V with AC. Shows a little better the temp sensor (blue arrows) and the thermo-switch with vacuum hoses attached (blue circle)...

 

[Vinnie]

Is it used by the a/c? My car used to have it but the previous owner (jack a$$) removed it...

 

[mjlan]

I don't think it is specific to A/C, I think it is the distributor vacuum control valve, it limits the signal to the vacuum advance on the distributor until a certain coolant temperature is reached.

Good info:

http://www.7173mustangs.com/thread-under-the-hood-mysteries-distributor-vaccum-control-valve

http://www.7173mustangs.com/thread-vacuum-hose-diagrams

This shows up on Rockauto, not sure if there are different ones out there that work off of different temps or not...

https://www.rockauto.com/en/moreinfo.php?pk=44435&cc=1132861&jsn=450

 

[Carolina_Mountain_Mustangs]

Great job my man. Going at the correct way and not trying gimmicks to get the screw out. I do hope you can get a tap to run into the holes to clean. If not I will mail you one if you will give your address for fee from U.S..

I was tool and die maker so I have lots, lol. I could actually send you a selection. 1/4"-20, 5/16"-18, 3/8"-16 then you would be covered. Let me know.

David

 

[Vinnie]

Oh, I got the taps (nice set of 3) and cleaned the thread. I now have a cast iron water neck coming my way from Germany so I have to wait till the weekend to continue.

 

[Vinnie]

I don't think it is specific to A/C, I think it is the distributor vacuum control valve, it limits the signal to the vacuum advance on the distributor until a certain coolant temperature is reached.

Good info:

http://www.7173mustangs.com/thread-under-the-hood-mysteries-distributor-vaccum-control-valve

http://www.7173mustangs.com/thread-vacuum-hose-diagrams

This shows up on Rockauto, not sure if there are different ones out there that work off of different temps or not...

https://www.rockauto.com/en/moreinfo.php?pk=44435&cc=1132861&jsn=450

Thanks for those links! I think my distributor advance is connected to my carb directly... Is that bad or good? It sounds like I want to use that sensor incase I get caught in traffic...

 

[Vinnie]

Those cheap chrome housings come with an oring but even using a

gasket is a fail and will leak ask me how I know.

Get a cast iron housing and use a gasket.

Paul

I received this today:

It's cast aluminium though and it's got a serial stamped in the side which I didn't know it would have.

Could the serial be a potential leak area? I'm putting the original hose back on coz I can't fork out the money for a new hose at the moment...

This is better?

 

[Bill73Ragtop]

Not likely you would have an issue with the stamped numbers causing a leak. Note the bump out at the end which is where 90% of the seal occurs. Pretty rough casting exterior, but paint should clean some of it up. The only concern with re-using a hose is if it's old and dried out / cracked / stretched out enough to prevent firm fit before final clamping.

 

[Qcode351mach]

Don't drill a hole in the thermostat. The correct Robert Shaw thermostat doesn't have one and nether did the thermostat installed from the factory. The Cleveland has a unique cooling flow and drilling the hole can actually cause more problems than it solves.

 

[Vinnie]

Don't drill a hole in the thermostat. The correct Robert Shaw thermostat doesn't have one and nether did the thermostat installed from the factory. The Cleveland has a unique cooling flow and drilling the hole can actually cause more problems than it solves.

Would you have a suggestion about how to get the air out after refilling? I really appreciate all the advice but it gets a bit difficult when advices are opposites...

 

[Vinnie]

Not likely you would have an issue with the stamped numbers causing a leak. Note the bump out at the end which is where 90% of the seal occurs. Pretty rough casting exterior, but paint should clean some of it up. The only concern with re-using a hose is if it's old and dried out / cracked / stretched out enough to prevent firm fit before final clamping.

Do I need to paint it?

 

[Carolina_Mountain_Mustangs]

Don't drill a hole in the thermostat. The correct Robert Shaw thermostat doesn't have one and nether did the thermostat installed from the factory. The Cleveland has a unique cooling flow and drilling the hole can actually cause more problems than it solves.

Drilling a .040" (1.0mm) hole in the thermostat will never cause an issue in any engine. It only allows the air to bleed out on it's own. It was in many thermostats for years but they took out saving them cost. I have done it on Flathead V-8, 240 6 cyl., 289, 302, 351 W, 351 C, Chevy 283, 327, 350 Oldsmobiles etc, etc..

We never built a race engine without putting the hole in the thermostat to escape the air. I, Knock Wood, have never had an engine failure of any type in over 1,5 million miles so I know it will not hurt anything only help. I did break one valve in flathead but it stayed in pocket and hurt nothing. We developed washer sizes for some race engines to take the thermostat failure out of the picture. You have to restrict the flow with thermostat or car will circulate water too fast and not cool in radiator. A .040" hole will not be noticed except you won't have any issue getting air bubble out of block when filling.

If you can fill me in on a problem it will cause I would sure like to learn. I learn new things every day.

 

[Qcode351mach]

If you can fill me in on a problem it will cause I would sure like to learn. I learn new things every day.

Reverse coolant flow/ sucking air into the port when the engine cools off

I've never in 30+ plus years of building engines replacing thermostats drilled a hole in a thermostat so there's both sides of the coin

Some say ya do, and some say you don't, Imho I guess it's up to the guy replacing the part.

 

[Vinnie]

When the engine cools off as in during or after driving? Coz the latter is not a big deal no?

 

[Carolina_Mountain_Mustangs]

When the engine cools off as in during or after driving? Coz the latter is not a big deal no?

There is no air on either side of the thermostat after you fill the system. The little hole in the thermostat just stops the belching of the system getting the air out. If there is air in the block when you first start the engine and the thermostat is closed as normal it holds air. When you start the engine the first time it has to heat up the thermostat enough to open before the air can get out. Without water being around the thermostat nothing to heat it up but the heat from the block. When it does open if you have the radiator cap off it usually spits out antifreeze everywhere because of the air escaping. The tiny hole eliminates all that.

If you are afraid something will happen don't do it. I am certain nothing will happen.

 

[Bill73Ragtop]

Do I need to paint it?

Not really, but it would look better painted to match the engine.

 

[Vinnie]

Do I need to paint it?

Not really, but it would look better painted to match the engine.

I have to make it look old and rusty? ;-)

 

[Vinnie]

When the engine cools off as in during or after driving? Coz the latter is not a big deal no?

There is no air on either side of the thermostat after you fill the system. The little hole in the thermostat just stops the belching of the system getting the air out. If there is air in the block when you first start the engine and the thermostat is closed as normal it holds air. When you start the engine the first time it has to heat up the thermostat enough to open before the air can get out. Without water being around the thermostat nothing to heat it up but the heat from the block. When it does open if you have the radiator cap off it usually spits out antifreeze everywhere because of the air escaping. The tiny hole eliminates all that.

If you are afraid something will happen don't do it. I am certain nothing will happen.

Clear. I'm gonna drill a hole then.

Thanks for the discussin' folks.

 

[73pony]

Do I need to paint it?

Not really, but it would look better painted to match the engine.

I have to make it look old and rusty? ;-)

Its not old and rusty. They call that Patina.