Again, great job Genscripter! When I bought my van the compressor was locked up. It was a rebuilt compressor so that meant it had already been replaced and had been converted to R134 according to the adaptor on the suction line. I bought a new compressor and was going to flush the system. I guess it had sat for years with an empty system because after taking the compressor off, the lines had lots of dry corrosion inside them. So then i thought, why spend the money on a compressor and all and still have the chance of crud in the system that could kill the new compressor like it might have done to the rebuilt one, so I just replaced the entire system. Mine only has front ac so the cost wasn’t as bad. I also went back with R12 because that is what the system was originally designed for and figured if I did a good job, I shouldn’t have problems for years and could convert it later if needed.
Mine is not getting as cold as it should but it’s not the ac system, per say.. When I start the van with the engine cold, the temps drop down to 42 to 45f. As the van warms up, the air temp raises to nearly 55f. There is no cutoff or bypass valve on the heater core lines and I believe as the engines warms up, It is mixing warm air from the heater core. That is my spring time job!

But good luck with yours and I hope it all works great for you.. The engine swap had to be a very big job...

 

If you want to do the shutoff valve easy, just cut your heater hose in the middle, then install one of these: (That's what I did. Mine's lasted two years so far without a problem.)






It's not an electrical valve or vacuum powered valve, so you gotta open the hood and turn the valve manually. But I figure that for the most part of the summer, I don't want any heat in my heater core at all, so I leave it closed for the whole season.

 

Thanks, that is a great idea. The only thing I am not sure about is I think there might be 2 lines, or at least 1, that come off the heater line near the engine, that connects to the throttle body.. So I don't know if the heater line can just be closed off. Perhaps it has to circulate?

http://s472.photobucket.com/user/Ann...tml?sort=3&o=0

 

Holy *****. You gasser vans have soooooooooo much room under the hood. I'm jealous.

Here's my situation:




As for determining your heater hoses, I would cut hose #1. You can see the arrow indicating the flow of the coolant. However, I don't know much about gassers, so I cannot fathom why you have a small coolant hose that goes to your throttle body. Especially hose that doesn't appear to loop back into the coolant system. I'm not really sure why that exists, unless it is used to warm something up prematurely. The flow out of the heater core lines are pumped instantly out the cylinder heads, so it's the quickest source of heat, but if that's the case, then why is it splice in the return line from the heater core, and now the supply line? All very confusing.

Since you have some sort of thing connected to your heater core lines, I'd hesitate to install a shutoff valve just yet. Maybe there needs to be flow thru that circuit to make sure that tee gets coolant to your throttle body. If that's true, then there is a simple solution. not as simple as the simple brass valve, but still pretty easy.

Buy two brass tee valves like this:





Then use a threaded nipple like this to connect the two valves:





Then cut both supply and return heater core hoses near the heater core, but leave enough hose to connect your new valves. Like 2-4 inches.

Install some 5/8" or 3/4" brass NPT hose fittings to connect your hoses to the four openings on your new valve assembly. Like these:





Then you have a two-way valve, that will allow you to turn both valves to have the coolant flow thru your heater core and keep flowing thru the circuit, or you can have the coolant flow bypass your heater core, but keep flowing.

But maybe someone can chime in on what that Tee is.

 

Well. My AC vacuum held ok. But it did reduce my pressure 5psi after two days. It could be that I left my gauges on the valves, and those do leak a little. I pulled another vac back to 30psi and took the AC gauges off. I'll check it again in a few days to see if it holds better without the valves on it.

 

You can install the valve in either line. Once you close the flow, the temp of the coolant in the heater core will drop to whatever the temperature is in the blower box.

 

The small hose to the throttle body runs back to the radiator. It's there to cool the TB, which collects heat from the EGR valve.

 

Good to know. I havent' worked on gassers in over a decade. Weird to think now. I remember getting my first diesel and thought it was alien. Now i'm so ballz deep into diesels that I can't work on gassers anymore.