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Discussion Starter · #1 ·
Hi people, i found a pool of coolant in the passenger side footwell after being away for the whole winter. - a sign the heater core is leaking.

i investigated further by pulling out the core, i see coolant residue in the passages. - a sign the heater core is leaking.

I wanted to find out where the leak in the core is to see if i can do anything about it without shelling out 380 dollars for a new core, so i plumbed up a pressure gauge, filled the whole core with water for safety, and hooked it up to my water main to see where it was.
15 PSI, no leakage.
30 PSI, no leakage. until finally.
45 PSI, over 3 TIMES the car's line pressure, and still no leakage. i couldn't check it for how well it held pressure, since most of the water was leaking out of my awful plastic garden hose fittings. i couldn't hear any hissing, i couldn't see beads of water looking through the fins, whats the deal?

I saw OSC radiators had a part number for my model of trooper in their e-catalogue, though. so I sent them an email and asked them if they still make this heater core, and if they sell them to end users (and if so, for how much).

Any thoughts on this, guys?
 

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Antifreeze / coolant will leak in places that water will not. If the leak is that small, there might be a sealant of some kind that would cure it. Dennis
 

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Rock auto lists them for rodeos I know. Cheap too, like 40 bucks. Maybe you can make one fit? Not sure the setup on troopers.
 

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I've seen radiators that looked like they were leaking but turned out that after years of heat and cooling, the hose had become harder so as the pressure built up, it leaked between the hose and hose fitting it connected onto.
 

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Hi people, i found a pool of coolant in the passenger side footwell after being away for the whole winter. - a sign the heater core is leaking.

i investigated further by pulling out the core, i see coolant residue in the passages. - a sign the heater core is leaking.

I wanted to find out where the leak in the core is to see if i can do anything about it without shelling out 380 dollars for a new core, so i plumbed up a pressure gauge, filled the whole core with water for safety, and hooked it up to my water main to see where it was.
15 PSI, no leakage.
30 PSI, no leakage. until finally.
45 PSI, over 3 TIMES the car's line pressure, and still no leakage. i couldn't check it for how well it held pressure, since most of the water was leaking out of my awful plastic garden hose fittings. i couldn't hear any hissing, i couldn't see beads of water looking through the fins, whats the deal?

I saw OSC radiators had a part number for my model of trooper in their e-catalogue, though. so I sent them an email and asked them if they still make this heater core, and if they sell them to end users (and if so, for how much).

Any thoughts on this, guys?
Heat is probably making a minute crack expand.
 

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Discussion Starter · #7 ·
Rock auto lists them for rodeos I know. Cheap too, like 40 bucks. Maybe you can make one fit? Not sure the setup on troopers.
I've had a look at the rodeo heater core, and it's a lot different to the one on the trooper. the trooper has a couple of plastic barbs that make a sharp 90 degree turn, with a regulator valve built right into the tank, and the rodeo has a couple of lines that run out of the tank at a 70-80 degree angle, with no valve.

Stopleak was used on this car in the past, made sure to flush the cooling system very well before i put in the new radiator. so maybe it has something to do with this? you'd think 45 PSI water would leak from the same places that 15 PSI antifreeze does.

Heat is probably making a minute crack expand.
That's what i'm thinking too. I might fill it with boiling water from the kettle sometime later and see how it fares.

I've seen radiators that looked like they were leaking but turned out that after years of heat and cooling, the hose had become harder so as the pressure built up, it leaked between the hose and hose fitting it connected onto.
Not too sure if it's a problem with the hoses. I know the ports have become ovalized from all those years of clamping, but if they were leaking, i'd notice it in the engine bay.

No response from OSC radiators yet, except an automatic email telling me the mail was undelivered.
 

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Discussion Starter · #8 ·
Alright. i put boiling water in the heater core, and still nothing leaked out. you'd think a leak like that which passively leaked out over the course of 4 months, at below 10 C, with no line pressure would show up from either that, or the 45 PSI hydrostatic test i performed. My only real lead here is that one of the heater hoses has cracks on the end, and that still doesn't explain how it got all the way into the heater box. because there is a lot of residue in there.

As for finding a replacement, I found this from a post on the isuzu p'up forum, but from further research, it seems that scs/frigette went out of business in 2006. Amazon.com: Coolforce 250-428 Heater Core : Automotive

I've been contacting manufacturers all across the board, OSC radiators, their parent company US motorworks, yoyoparts, SCS group, None of them seem to feel like responding to their e-mails, even though i keep bringing up the option of getting them into contact with major suppliers like JLEMOND's company, or RockAuto.

If you're reading this, and based in the USA, can you please give these guys a call? Home

Ask about part number 99224, if it's still available, and if they are willing to sell it to end users.
If so, ask how much it is, if not, ask about their MOQ and price breaks. I'd love to see these original heater cores made cheaper and easier to get.

The lack of parts for this car is getting absolutely ridiculous, you'd think it was made in the soviet union or something.

Something positively has to be done about this, if these manufacturers don't want to answer, i'll have to take matters into my own hands.

Word has it that the heater core from a 1978 bronco is a very good fit, that it has the right spacing between the barbs, that it has the right dimensions to be a good candidate, that it's far, far cheaper, and that it has aluminium tanks as well. only trouble with it is that the barbs extend too far forward towards the exhaust manifold, and it doesn't even have that handy in built regulator valve.

I am NOT having the thing run constantly, and i'm sure as hell not going to put a ball valve down in there that i'll have to grope around for in the middle of a cold night.

The clearance hole for the old heater core's lower is made oblong to give clearance for that weird skinny port on the inbuilt valve. and what i'm thinking is, if the heater controls can be modified to suit a choke cable type thing, and if it can be routed through that preexisting hole towards a more traditional heater control valve under the hood. (if all else fails, a new hole can be drilled in the firewall to run it through)

I'd like to make a kit which includes everything you need to convert to the ford heater core, which includes the core itself, cut down, bent, and beaded to better suit the gen 1 trooper/isuzu p'up, the cable, the heater valve, a new 3d printed lever arm that clicks straight onto the D shaped keyway on the stock heater box, and 3d printed brackets to allow the core to slide straight into the stock heater box and mount in the preexisting screw holes. hardware included.

HEATER CORE SIZE - Page 2 - IsuzuPup.com This report says it's thinner, narrower, and about 1/2 longer than the original core which is perfect. the 3d printed brackets will mount on both sides of the bronco heater core and fix to these mounting slots, and are going to need some clearance to do that.

Rectangle Wood Font Flooring Hardwood

(p/n is OSC 98571)
All of it will go for, oh i dunno. 120-150 AUD? Far less than the 385 USD a new OEM core will cost.

It will need to be compatible with both LHD and RHD models of trooper, involve as little modification to the vehicle as possible, be (relatively) easy to install, and operate just as easily and conveniently as the OEM core did. No auxilliary controls mounted to the dash, no ball valves in stupid locations, all you should have to do to turn on the heat is pull the old lever to HOT.

What do you guys think? Do any of you have any ideas for how this should be set up? perhaps more suitable cores for this application? (i originally wanted to use a nissan core because they had a couple of blank holes on the top you could mount different barbs in, but they were way too big. the dimensions of the original core past the mounting flange are 190mm long, 165mm wide, and about 63mm tall, if you count the little plastic standoffs at the bottom of the rear tank.)
 

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I just tried calling them but didn't get a live person. When you say that you found the leak after being away for the winter does that mean the vehicle was not being used at all in that time and thus leaking passively? Could it have been a leak from when it had been running prior but hadn't evaporated in that time? Seems odd that it didn't show signs of leaking with your tests. I would look for the leak elsewhere. Somewhere that it could have run down into the box perhaps?
 

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Discussion Starter · #10 ·
Yep. The vehicle was sitting dormant for 4 whole months while i was away, and when i came back, the antifreeze was pooled in only the passenger side. (would be the drivers side in the US).

I did see antifreeze in the heater box facing corner of the foam wadding, as well as antifreeze residue in the heater box and vents, which you'd think would mean it's coming out the core. but I couldn't get this darn thing to leak no matter what i tried.

It's a shame OSC isn't picking up the phone. Perhaps it might be an idea to try calling their parent company, US motor works, and see if you can get the operator to patch you in, or give you information about that part.

Thank you very much for taking the time, though! Need all the help i can get to contact these guys about this aftermarket heater core.
 

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Discussion Starter · #11 ·
Did another test, found the water was leaking by the hose barbs, since they had both been ovalized from years of heat and pressure from the hose clamps.

I'll try to straighten them out with a torch and vise, and if it still leaks, I'll buy a new heater core for an exorbitant 380 USD.

Forget everything i said about finding new suppliers, or making retrofitting kits. Most of these cars have long since been fed into shredders so i won't be able to sell these kits to damn well anybody. The suppliers obviously think the same.
 

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Discussion Starter · #13 ·
Alright, i put the core back in, and it looks like it isn't leaking after all. Maybe my 45 PSI test might've pushed something back into place, or maybe it was the ovalised ports causing a leak into the cabin. I did see one of the heater hoses was cracked on the end, so i cut that off and so far, i haven't seen any coolant in the cabin.

If it was a cracked hose, it'd explain why it was leaking passively.

Fingers crossed!
 

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Discussion Starter · #14 ·
Case closed. The coolant was leaking from around the hose barbs and seeping into the cabin that way. Heater core was 100% fine, that's why it didn't spray water when pressurized under a water main.
 
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