New Summit heater and possible water pump issues?

Ok, here we go…

I bought and installed the Summit heater for my 62 CJ5 F-head, installation was smooth enough. Had to shorten my "glove-box" aka old ammo can. I bought this unit because my original heater was anemic at best, and wouldn't defog worth a darn, which is pretty important in the Northwest. However, the Summit is barely putting out any better heat, sometimes it feels more like air conditioning. I've tried "burping" on quite an impressive hill several times, with the radiator cap off. I even installed a little air bleed device that I quickly turned on the lathe. I don't think there's any air in the heater (even though the inlet/outlet lines are right at the top of the firewall, and might be higher than the rest of the cooling system). Just to make sure there was nothing stuck in the lines, I've twice now hooked up a siphon to the outlet hose on the heater, and gotten super hot fluid returning after a few seconds of cold fluid first, and no air. So this has me thinking, is my water pump just shot? Is it possible to just not have enough "ummf" to get fluid through the new core? It is the original pump, and I don't believe it's ever been touched.

Extra info: All new fluid, it's been flushed now twice. New 190* thermostat. There's no leaks in the system, no new air getting in. Also, every time I start from cold, the temp gauge will go to almost ~210* then fall to ~195*

Any ideas at all? New pump?

Looking up behind the dash


Air bleed device, which I get straight fluid out of, no bursts of air.


Inlet/outlet at top of firewall… maybe higher than the rest of the water system?


Here's a quick pic of the unit plus a cheapo squirrel guard for the fan inlet.

 

I have seen old water pumps with the impellers severely diminished by corrosion. Could reduce the flow, and heat-exchange rate is a function of flow rate.

 

Sounds like either a coolant routing/control issue or a base cooling system issue. I installed one of those heaters in the Daughter's Jeep and on low would heat you out of the Jeep in our climate. Made me such a believer I sold the '72-'75 heater out of the CJ-6 project to put one in.

 

Well I'm stumped. And I've got a luke-warm heater to get me through the winter. Shoot.

I suppose I'll be taking the water pump off next time I get bored, but I have a feeling it's something else.

 

I was wondering the same thing.

 

Heater inlet is coming from back of the block. Regardless, the summit has no specified inlet or outlet connection. They're universal in a sense. All to say, it doesn't matter which way I have the hoses connected, one will have hot comin in, one will have cold going out.

 

Heaters may be universal, but the ports on the engine and water pump may not be.

 

Ok Guys, where is the pressure flow test in the outlet heater hose from the engine to the heater core and what would the rig look like? How about a temp gauge with a number dial at the heater end too?

 

Well, as luck would have it, I haven't changed a thing since my last gripe. I've just been driving around like normal, and about a week ago the heat starts working! Hmmm… interesting. And just in the nick of time, as it's 20F right now. I was thinking I could boost (and should have done earlier) the flow to the heater by removing the bypass hose on the block. But oh well, it's working now, and I don't really want to drain this thing one more time and create some more air bubbles.

I made a nifty contraption that articulates based on where I want to direct the in-cab heat, and it's well hidden when sitting in the seats. I also have a threaded plug for this vent, in case I need to divert all flow to the defrost. You'll also notice the Summit switch is snugly placed between ignition and the speedo unit. It's actually an OK switch, and matches the silver/black/green theme I've got going on.



Under the back bench seat, I've got a little Amazon special 120V heater that I've attached to the seat itself. This keeps it from rolling around back there as I bump down the road.


I've also installed an engine block heater via the lower rad hose. I think I've already shared this… but in the wake of this cold weather, I figured I'd recap all the nice heating elements.


To top it all off, everything is wired to a marine grade through-wall outlet, so that when she's parked, I can leave it all plugged in with one cord. I just set that cord to a timer for early morning.

 

Sounds like you still had an air lock in the system and it finally worked its way out. An air pocket can limit the coolant flow and keep the heater (or radiator/cooling system) from being effective.