78 Monte 4 speed

[Geo's66]

Problem and need help- 2 things on build-
1. Vents aren't opening in dash:
(1/2) Still a few issues- heater vents must have vacuum leak because vents do not open or close. Having a overheating issue..not pushing water out but can hear
any suggestions please! Ugh

 

[TURNA]

If you hear the water flowing you are low on coolant/water

You may have an air bubble in the system

 

[Geo's66]

Thanks- how does an air bubble happen and how to get rid of it- how would I know either way? Thanks- then we need to tackle the dash vent issue- disappointing at this point-

 

[TURNA]

The bubble will work its way out, you can burp the system with a cap like this.

I have also used a bleeder in the thermostat housing.
Something similar to the second pic

 

[pontiacgp]

Thanks- how does an air bubble happen and how to get rid of it- how would I know either way? Thanks- then we need to tackle the dash vent issue- disappointing at this point-

I use one of these, it keeps the coolant in the funnel higher that any part of the engine...

http://www.lislecorp.com/divisions/products/?product=606

 

[Texas82GP]

Get the car sitting on an incline to make sure the radiator cap is the high point in the cooling system. Remove the radiator cap (engine cool). Check the level. If it is a little low, that's ok. Crank the engine and let it idle and warm up. Monitor the temperature of the upper radiator hose with your hand. When it gets hot, the thermostat has opened. All the while, watch the level in the radiator. Run the heat on the hottest setting during this. Monitor the heater hoses during this to make sure they get hot. Have an old towel handy and the radiator cap handy in case the level surges up when the thermostat opens. Once the thermostat has opened and the level has stabilized, put the cap on the radiator. Be sure the level in the overflow tank is correct, and turn the engine off. Let it cool completely. Remove the cap and top off the system. Drive normally and observe. Report back with results. This should do the trick.

 

[Texas82GP]

On the vents, is the pink vacuum line under the hood connected to the vacuum sphere under the hood? Is the vacuum sphere intact (holds vacuum)? Is the vacuum sphere connected to manifold vacuum? Do you hear hissing inside the car? Is all the air coming out the defrost? We need more detail.

 

[Geo's66]

This is awesome information, thanks guys and will get back to you right away- the other concern was the flow direction of the water pump... The engine builder and my guy are speaking this am to make sure it's not as simple as that..

 

[Geo's66]

We are jacking up front end of car to burp the coolant system...
The vents in the dash won't open, heat only comes through floor and defrost- with the big engine(550hp dart block), is there a chance the cam won't create enough vacuum?
What is the standard vacuum reading for the vents to work? Can someone help on that??

 

[Texas82GP]

We are jacking up front end of car to burp the coolant system...
The vents in the dash won't open, heat only comes through floor and defrost- with the big engine(550hp dart block), is there a chance the cam won't create enough vacuum?
What is the standard vacuum reading for the vents to work? Can someone help on that??

It should make enough vacuum at idle if there isn't a leak. You could test with a Mighty Vac. They have them on the loan atool if you don't have one. This is just a little bug.