jabos7 Posted September 21, 2019 Report Share Posted September 21, 2019 Spit Greetings to all, and HELP! Can anyone tell me the coolant filling procedure on a 1500 that has the system cap located on the Thermostat housing? First attempts resulted in the coolant mixture instantly filling the space below the cap and spilling back out without moving further into the radiator or engine. I recall on my rebuild as I cleaned and repainted the housing (between the cap and water pump) that I could not figure out the passage paths through the housing. No clear shots visually. How did they even cast these pieces??? I ended up pulling the top hose for a messy fill and slamming in back on, but I know I have some air/room still in the system. Any hints or guidance would be greatly appreciated, and would cool me off in more than one way! Cheers--Jeff/Maryland Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 21, 2019 Report Share Posted September 21, 2019 I'm so unfamiliar with these that I had to search the Net for photos, but my first suggestion would have been from looking at the layout, as you did, to remove one of the hoses and fill it that way, with the end of the hose held well above the engine. I'm assuming - and feel free to enlighten me on the setup - that you can fill it most of the way by this method, then trickle top-up by letting coolant drip through the thermostat? Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 21, 2019 Report Share Posted September 21, 2019 Also its Important that the thermostat has a air bleed jiggle pin in its rim to let air out as you fill. Or a 3mm hole drilled in the rim Pete Link to comment Share on other sites More sharing options...
jabos7 Posted September 22, 2019 Author Report Share Posted September 22, 2019 Colin -- that was my first effort, and seemed reasonably successful and messy. But when I see one of the Midget housings with the removable plug/nut it makes me worry that I'm not truly topping up my rig like one could with that opening a the highest point (even though they did have a multitude of problems with dissimilar corrosion around that plug. Pete- I'm good with the airbleed hole, but the odd casting of the upper section seems to keep me from getting coolant even down to the thermostat, let alone filling the block and radiator. There's gotta be a secret I'm missing here...... Link to comment Share on other sites More sharing options...
poppyman Posted September 22, 2019 Report Share Posted September 22, 2019 I think i know the system you mean? Have you tried filling it through the top heater hose which should be above the hight of the cap? Tony. Link to comment Share on other sites More sharing options...
jabos7 Posted September 23, 2019 Author Report Share Posted September 23, 2019 Here's the evil invention. It looks like an open passage would run through, inlet to outlet, but noooooo! Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 23, 2019 Report Share Posted September 23, 2019 Ive never had a problem filling a gt6 but have put the front up on ramps and discon the heater hose to let air out Pete Link to comment Share on other sites More sharing options...
JohnD Posted September 23, 2019 Report Share Posted September 23, 2019 Fill up, start the engine, with the rad cap off. Nothing will happen until the 'stat opens, when coolant will start to be circulated, with any trapped air. That will escape out of the open cap, top it up as you go, when no more escapes, close it up. Done. John Link to comment Share on other sites More sharing options...
Badwolf Posted September 23, 2019 Report Share Posted September 23, 2019 I actually tried that when I got an airlock when I recommisioned the car. Sadly no joy, The only way I could clear the air was as per Pete's instructions. No more problems. Link to comment Share on other sites More sharing options...
jabos7 Posted September 24, 2019 Author Report Share Posted September 24, 2019 JohnD - I've done that on a standard radiator cap, but are you saying it should work with this housing/cap? -There's no flow-thru here, despite the appearance of the housing in the picture. Even bone-dry, on the first fill attempts, the coolant would not carry from under this cap onwards into the hoses/radiator. Poppyman--sadly I'm not running any heater hoses, but your suggestion might lead me to attempt that fill where the heater hose would meet the housing. -Hope! Link to comment Share on other sites More sharing options...
Gully Posted September 24, 2019 Report Share Posted September 24, 2019 I've just been looking at the full picture on Canley's site and I don't understand why coolant poured into this cap wouldn't go into the hoses - it should flow across the top of the closed thermostat and into each of the connecting pipes, effectively filling the block from the bottom up. Then, when the thermostat opens, the water is released from the block to circulate through the housing back into the radiator. Has the thermostat been installed incorrectly (or the wrong thermostat) so it's blocking the housing in some way? The GT6 handbook sets out the cooling system filling step by step - does the 1500 Spit handbook do the same? Gully Link to comment Share on other sites More sharing options...
JohnD Posted September 24, 2019 Report Share Posted September 24, 2019 jabos, Ah! You have some modern jiggery there! I retire to my cave. John Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 25, 2019 Report Share Posted September 25, 2019 Is this a new housing , has the engine been filled before , is there a casting problems here?? Pete Link to comment Share on other sites More sharing options...
jabos7 Posted September 26, 2019 Author Report Share Posted September 26, 2019 this came on my donor engine after mine cratered. During the rebuild I noticed you couldn't see through this thing one way or the other. The passages either cross or turn just far enough in to thwart logic. I'm going to jack it up as suggested, fill as much as I can into the top hose disconnected, then fire it up and see if it pulls down after the thermostat opens. Give me a couple days and I'll let you know what happens. --Any further suggestions are certainly welcome -Jeff 🔨 Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 26, 2019 Report Share Posted September 26, 2019 Strikes me there is a casting problem here with blocked water ways Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 26, 2019 Report Share Posted September 26, 2019 1 hour ago, Pete Lewis said: Strikes me there is a casting problem here with blocked water ways Pete I'd be very tempted to advise removing it, then see what it's like - if as Pete says there are casting problems it won't help the engine when it's running. You're better finding out in advance, and having better access to clear any obstructions if there are any. 1 Link to comment Share on other sites More sharing options...
jabos7 Posted September 28, 2019 Author Report Share Posted September 28, 2019 Well, finally success....kinda. I believe I finally got the system topped up, as best as possible for now. With the cap off of the housing I could flex the upper hoses by hand and hear the air come into the cavity below the cap. I probed all around that cavity with a bent wire and still could not find any internal openings, yet the air said otherwise. So I proceeded to fill the area under the cap, about 3 tablespoons at a time, until the level was up into the cap seal area, then "burped" the upper hoses' air into this cavity until the level came down to just air, and then repeated - over a dozen times. I finally reached the point where flexing the hoses only makes the coolant level rise and fall, no bubbles. I'll run it this weekend and see if any air collects back into this cavity, which should be the highest point on the system, and repeat my process again if necessary. Bring me the head of the engineer that dreamed this up..... Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 28, 2019 Report Share Posted September 28, 2019 The is no spoon listed in the tool kit............., this all sounds a bit nuts Its far from Normal . Pete Link to comment Share on other sites More sharing options...
SpitFire6 Posted September 28, 2019 Report Share Posted September 28, 2019 On 23/09/2019 at 01:26, jabos7 said: Here's the evil invention. It looks like an open passage would run through, inlet to outlet, but noooooo! Hi, Looking at the picture above. I would block any passage between the two. Blocked the hole/path in the water-pump for the same reason. Why would you want an orifice between inlet & outlet on a correctly designed system? Am I missing something? Thanks, Iain. Link to comment Share on other sites More sharing options...
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