cooling sytem mod did not work!

It was time to replace my heater and rad hoses and since I am planning to make an all copper heater hose system, I just needed to tide things over for a couple weeks. I have the closed cooling system and decided to just bypass the heater core for now, with the 2 heater hoses hooked up directly to the overflow tank.
Well, let me tell you this does not work! the coolant gets pumped into the overflow tank so hard and fast that it shoots right across (lenthwise) and splashes against the far side. the problem with this is it gets foamy. i went for a very short drive - mebbe 2-3 kms and checked the tank - it was just full of foam which I know is not good for an efficient system.

anyone else tried to do this with different results?

Typically when bypassing a heater core you hook the hoses together with a piece of pipe, not into something else. Not familiar with the closed system, but it shouldn't be THAT different.

With out going out and looking at my 90' I would guess that you should have done the bypass at the heater core connections. The bottle is a surge tank and only takes in and lets out fluid based on the temp of the coolant and the expansion of the coolant. Its not really made for cross flow.

I plan on doing the same copper piping on my coolant system when it needs hoses again and I'm going to eliminate the heater control valve with 3 ball valves one each at the inlet/outlet of the heater core and one inbetween the 2 heater hose connections to allow the bypass to be cut in or out.

My $.02

with the closed system, one heater line comes from the waterpump and goes to the heater core, but it tees off to the overflow tank as well. I just replaced that teed line with a straight line to the overflow tank.

then there is an outflow line from the overflow tank that goes back to the engine, and the return line from the heater core tees into that. I'm going to have to put it back together that way.
sucks! gotta get this done tonight as I'm going wheeling tomm

xjtrailrider said:

With out going out and looking at my 90' I would guess that you should have done the bypass at the heater core connections. The bottle is a surge tank and only takes in and lets out fluid based on the temp of the coolant and the expansion of the coolant. Its not really made for cross flow.

I plan on doing the same copper piping on my coolant system when it needs hoses again and I'm going to eliminate the heater control valve with 3 ball valves one each at the inlet/outlet of the heater core and one inbetween the 2 heater hose connections to allow the bypass to be cut in or out.

My $.02

Click to expand...

that's right, that's right!! I did do my bypass at the wrong place. I'm going to try it as you suggest. Thanks!!

but wait a minute - why bother then, I still need those fricken tees...... gotta think this out some more.

nope - something is very odd here. I did up my copper lines which exactly copy the OEM lines and the coolant still shoots into the expansion tank. I just don't get it! I'm starting to wonder if there isn't some sort of restrictor to the expansion tank in the OEM lines.... I remember watching it before I messed with it and the coolant would sort of dribble into the expansion tank - you could see it dribbling down right where the hose goes in. now it shoots right across, and when I rev up the engine it just whips into a foamy froth. I'm going to dissect the oem lines tommorrow and see if there is a restrictor of some sort...

said "screw it"! ordered new oem heater hoses today.

interestingly, the ones I took off the jeep had the hoses crimped onto the metal tee and heater valve. when ordering replacements, the hoses and tee/heater valve come separately so I didn't bother buying the tee and heater valve as mine are fine...hmmmm maybe should rethink that heater valve, eh? it is plastic after all....