Heater coolant diverter and LS water pump, huh??

['68 Newtricks]

Hey folks, hoping to get some help and maybe mounting pics of this set up. Here's the pictures so we know what I'm talking about, then the question afterwords.





I'm trying to tie in my Old Air Products coolant diverter valve into the coolant lines from the water pump. One of the water pump lines is larger than the other, so I'm not sure how that hose is going to connect. Is there a way to pull the nipple off and put a smaller one on? Also, is the larger nipple out and the smaller nipple in? I don't know how these work, my SBC no problem, but the LS is new to me.

Lastly, does anyone have pictures or experience in mounting the valve? I'm thinking against the wheel well but it's not the prettiest spot. It seems good for hose routing and the electrical plug.

Thanks

[truckdude239]

What is that for? I just hooked my heater hoses to the pump but I still using stock heater

[pwdcougar]

On some of the newer engines the heater core is an integral part of the engine cooling system. If you were to block off the heater core connection, a part of the engine would not receive proper cooling. When you hit the max cool setting on the AC the diverter valve bypasses the heater core and allows the coolant to flow properly. I used one from a Ranger on a project once.

No idea why it is necessary for this application though.

Can you get a hose from an autoparts store that has two different sizes molded in? On my old Cougar the bypass hose that goes from the water pump to the intake is a molded L shaped hose with two different sizes.

Paul

[BR3W CITY]

Is this one of the things that people put in because they feel like their heat is running at all times in these old trucks?

The cooling system on LS motors doesn't flow the same direction as on SBC's, so I personally would suggest against any sort of temporary diversion of coolant. The LS is sooo damn sensitive to air in the cooling system (hence the steam lines, crossovers, plumbing into the high point or the pump), I wouldn't want to do anything that changed coolant volume, flow, or pressure...too many risks for me.

['68 Newtricks]

Hold on guys, kinda heading the wrong direction.

This valve came with my Old Air Products AC unit (like a vintage air setup) It needs to be plumbed between the heater core of the unit and the T-stat housing/water pump. It receives a signal to either let coolant into the heater core or continue to let it circulate back into it self. This valve is a must install for these types of AC units.

[mongocanfly]

Maybe this is what your looking for.. you may already know this but on the valve ..top left-from wp..bottom left-to wp..top right-heater in..bottom right-heater out....on the pump 5/8" supply to heater core 3/4" returns from heater core ..I've read where some people remove the water pump fittings and drill and tap and install hose barbs with npt threads..this way you can use a barb size that's correct for your hose. If you mount it on wheel well you could make a sheetmetal cover to go over it so that only the hoses going in and out would show.

[mongocanfly]

Drill and tap pump like this and add barb fittings

[ls1nova71]

With a little effort, you can get a 5/8 hose over the 3/4 nipple on the water pump, then just run all 5/8 hose. I've done it that way before and never had any issues with it.

[mongocanfly]

Ditto..ls1nova..that's how I did mine to.

[BR3W CITY]

Learned something new here. Never seen one of these before. So are you still using the stock heater core then, or did the HVAC setup you bought change that out too?

[68c10airstream]

The heater part is from a stock 96 and up vortec 5.7 as I will be installing it in my ls ac stock swap soon. It's purpose is to divert coolant back to the pump and stop flow to the heater core instead of stopping flow to heater core and have that line dead headed.

This is for max ac position (in stock apps anyway) and usually recirc heater blower air also in max position. This was part of my 2 year auto schooling in the late 70's

['68 Newtricks]

I'm using the Vintage Air under dash style set up. It requires the valve and controls it on it's own.

[Andy4639]

I don't have the fancy shut off valve I just installed a manual shut off in the heater core line. It doesn't hurt a thing. I can't see how this can hurt anything other than your AC outlet temperatures. Which is why I installed the valve in the first place. If your vacuum valve isn't working like it should be then your AC temps suffer. A quick feel of the heater box inside the truck with it running and AC on will tell the story. It should be cool to the touch if any hot water is getting through your AC isn't cooling like it should.