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Heater core issues

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I'm starting my rebuild on my heater system. Almost everything is in good working condition. The problem is the valve on the core, frozen solid. I'm currently in the process of trying to break the valve free... gingerly, dont wanna break it.

 

Has anyone had this issue, have this issue, fixes etc? Ive done some digging and cores from other models are all different.

 

Or, alternatively, anyone have a spare that doesn't leak and the valve is not frozen.

 

My current plan, if I can't find n alternate solution is to cut off and hollow out the valve, and cap it off. And then I would add a plumbing fitting onto the back of it. If I'm forced to go this route, I'll be sure to post pictures for posterity.

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If you squirt it with WD40 and let it sit for a few hours or overnight, that would probably do the trick. Then before you reinstall it in the truck pressure test it with water so you know it's going to work.

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Thats exactly what I'm in the process of doing. Its been soaking for about 3 or so hours, I'm going to flip is and let it soak from the inside as well. I'm not hopefull though. If these fittings sit long enough, even if you can beak it free, the likelyhood of it leaking is high. I don't want to apply heat as that might bugger up the solder fittings inside the core.

 

My Dad is a plumber and I'm using his assistance on this.

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^^ Thats kind of along the idea I had in mind, aside from using a different core. I will probably use a solinoid with either a pot switch, or go simple and just use a toggle... Again, this is just ifI can't get the stock valve to work.

 

 

One thing I did want to add, the main reason I'm not overly optimistic about using penetrating fluid. Think about how this valve is designed. It's meant to be water proof. If I do get any real penetration with the oil, it could really only mean there's a leak. We'll see later on.

 

It seems I might have the right idea by bypassing the valve.. Was just hoping there might be some clever known fix that I hadn't run across. Not seeming like it.

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The 521 valve is pretty simple. It's a brass valve inside the housing and it seals with a simple o-ring and is restrained with a set screw. Try this, remove the set screw and spray some penetrant on the valve and heat it with a heat gun or propane torch lightly (remember penetrant is flammable). put a vise grip on the valve and gently work it back an forth. Once it gets warm and the penetrant goes in it should pop free. Clean up with a brake hone and a new o-ring and your set.

 

Mark

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^^ Thats kind of along the idea I had in mind, aside from using a different core. I will probably use a solinoid with either a pot switch, or go simple and just use a toggle... Again, this is just ifI can't get the stock valve to work.

Solenoid??? switch??? Why make this complicated???

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Not that complicated actually mike. All I have t o do is tap off of one of the many abandoned power lines under the hood, I throw it inline with the water hose, run the wires inside, prolly hook it up in an inconspicuous place under the dash, and viola.

 

As for datsunrides' idea, tried getting the set screw out, bugger is frosen in real solid. As far as heat, still real cautios about that as if I screw up any of the solder work, I'm up a creek in a bad way. I'm trying to fix this in a way that I'm out as little money as possible, and going to a radiator rapair will run me a minimum of 100, more like 150 when all is said and done. And if I wreck any of the solder joints inside the unit, I'll prolly end up having to go.

 

I'm not sure the last time this thing was operated. I can't help think its been sitting since the late 80's when this truck went to Arizona.

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The best way is to remove the core and stick a wooden dowel in through the inlet/outlet and tap it out. The brass will break very easy if your prying with pliers. Yeah don't forget to remove the very tiny screw.

 

SANY6687_zpsdf0b280c.jpg

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The whole assembly pops out with four screws and the two heater hoses removed. Vent hoses and vent lever and a couple wires.

 

SANY6699_zpseb384cd2.jpg

 

SANY6688_zpsdf9eff5b.jpg

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Man those heaters are small . I had one through many Ontario winters and would barely defrost the windshield. Ahh those were the days...

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I did the same as dat521... cut and paste from my thread...

 

Heater work...20141126_174402_zpsbxo1l2el.jpgdidnt blow very well...20141128_125625_zpsfcregfmj.jpg flushed out core. 20141126_202502_zpsbekbuusv.jpgFan motors and housings kinda different between 70 and 72.20141126_210100_zpsf145vd9t.jpg20141126_205845_zpsbylcgdib.jpg  all cleaned.20141126_232530_zpsjegf4cie.jpg 20141126_232547_zpsto2vzjeo.jpg

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Indeed. Mine was full of maple keys and the foam needed some weather striping to seal the air leaks. I ran a 190F thermostat in the winter and some cardboard in front of the rad to speed warm up. Window cracked open to keep your breath off the glass. It was barely adequate down to 20F which was most of the winter but it would go below 0F.

 

Eventually I removed the glove box and put an air conditioner condenser in there. It was about 9" x 9" x 3" thick and a '50s fan housing and motor. Hoses to the air ducts and the hot water supply, some wiring. That fixed it for good. Heat was regulated by rolling the window down. 

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Just knocked it out, actually came out quite easily. Gonna clean her up, pressure test it, and if good, get a new o ring and I guess put it all back together.

 

Really didn't expect it to come out so easily.

 

There is a bit of green here and there which has me a bit concerned. We'll see, fingers crossed

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What are people using to replace the cardboard? piece that attaches the heater to the fresh air duct?

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Thanks for all the excellent info. I'm having the same issue with a frozen shut-off valve. Gonna get on it tomorrow and tap it out.

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