Heater Core Line Question

[GitEmSteveDave]

Noticed a small coolant leak the other night which I attributed to a screw hose clamp on the bottom of the tank b/c I could see some coolant at the top end of the hose above the connector. Took it apart last night and re-positioned the hose and made sure the screw clamp was above the barb on the coolant tank. Seemed to work and when I drove back to where I was staying, there was no visible steam or anything, so I thought I got it.

This morning, in the light of day, I drove to work and when I got out, I could smell the burnt coolant. So I popped the hood and found a wet spot, and could see a trail that lead to the heater core hoses. I threw some gloves on and after moving the lines a bit, it appears that either through friction or maybe galvonic corrosion, there is a small leak in one of the hoses.

So the question(s) are:

Is there some kind of temp fix I can do, like maybe a screw pipe clamp with some electric tape folded into a square to cover the hole for now, until I can order a replacement part

and

Is this hose/line set from Dorman good? It has nearly all positive reviews, and it's also pretty much the only model/brand offered at my local auto parts store and it's over half less than the mopar version. https://www.amazon.com/Dorman-626-516-Engine-Heater-Assembly/dp/B00NF1RKFE

Thanks!

 

[KJowner]

Noticed a small coolant leak the other night which I attributed to a screw hose clamp on the bottom of the tank b/c I could see some coolant at the top end of the hose above the connector. Took it apart last night and re-positioned the hose and made sure the screw clamp was above the barb on the coolant tank. Seemed to work and when I drove back to where I was staying, there was no visible steam or anything, so I thought I got it.

This morning, in the light of day, I drove to work and when I got out, I could smell the burnt coolant. So I popped the hood and found a wet spot, and could see a trail that lead to the heater core hoses. I threw some gloves on and after moving the lines a bit, it appears that either through friction or maybe galvonic corrosion, there is a small leak in one of the hoses.

So the question(s) are:

Is there some kind of temp fix I can do, like maybe a screw pipe clamp with some electric tape folded into a square to cover the hole for now, until I can order a replacement part

and

Is this hose/line set from Dorman good? It has nearly all positive reviews, and it's also pretty much the only model/brand offered at my local auto parts store and it's over half less than the mopar version. https://www.amazon.com/Dorman-626-516-Engine-Heater-Assembly/dp/B00NF1RKFE

Thanks!

Check the pipe isn't paper thin, it would be a shame to boil the engine if the leak suddenly gets worse, as a temporary solution I've just looped hose in place in other cars. Has the coolant been changed regularly? If not it becomes corrosive and eats the aluminium parts from the inside out when the inhibitors are exhausted.

 

[GitEmSteveDave]

Check the pipe isn't paper thin, it would be a shame to boil the engine if the leak suddenly gets worse, as a temporary solution I've just looped hose in place in other cars. Has the coolant been changed regularly? If not it becomes corrosive and eats the aluminium parts from the inside out when the inhibitors are exhausted.

It was still at operating temp when I looked at it earlier today, so I'm about to go down and look at it now that it is at room temp to see if I can feel the hole. Is it safe to replace the metal hose w/rubber? I always assumed that metal hoses where used where it's high pressure. If so, what size should I get at Napa(only place I know nearby that sells hose by the foot)?

I had a actual radiator leak in late December 2022, so it was replaced under warranty and my mechanic put all new HOAT in it, as well as upper and lower hoses that day. I've only run green coolant once, when my mechanic(at the time) refused to use HOAT in it. When I left that mechanic(after the warranty on the work expired), I had Jeep power flush and fill it, which was like 2020 at the start of the pandemic, if memory serves me right.

I also run a OBDII dongle at all times I'm driving, so I would def notice if the coolant started getting too hot. In addition I have a alarm set up if it every goes above 230F.

 

[KJowner]

My Jeep is diesel so I don't know if we have the same hose diameter, the aluminium sections are to make the installation as neat and compact as possible not because of pressure, the system only runs at a few psi.
If the coolant has been charged regularly then it should be OK, it may be vibration that's caused the damage.
You can replace the leaking line with rubber hose, just make sure it is clear of sharp and hot bits, cable ties will come in handy!
You could also patch it temporarily like your said if access is OK where the leak is, a bit of soft hose split to slip over might be better than tape.

 

[GitEmSteveDave]

So I seemed to have made a fundamental mistake and by touching the thing, just like a tent in the rain, it's leaking even worse now and since it's flowing down onto the engine body, every time I come to a stop it's like backstage at a Willie Nelson concert . But I also ordered the Dorman set above through my bosses Amazon Prime, so hopefully it'll get here before the end of the week and I can unbolt the coolant bottle, save whatever coolant is inside the bottle by disconnecting the overflow hose at the radiator & collecting it in a jug and replacing what I loose with new coolant considering what I'll save by DIYing.


In the interim, I've considered just disconnecting the metal line at both ends and running a rubber hose from the nipple behind the idler pully, over the air cleaner hose, and onto the heater core nipple, thus bypassing anything really hot that could melt the hose.
BUT, without knowing the hose size, I'm at a loss. I tried measuring the outside of the hose, but the hose at the front is ~24mm OD and the one into the heater core is ~27mmOD, as measured by a caliper in multiple spots that I could reach on each.


Are the hoses at each end different Inner Diameters? Or does it not matter when the difference is that small and hose clamps can make it secure enough for a week?

 

[KJowner]

That's a pain, I honestly can't tell you if the hose will compress or stretch enough to jump between sizes, however another option is to loop between the feed and return ports and live without a heater for the time it takes to get the replacement lines.... assuming the ports are the same size there.

 

[GitEmSteveDave]

That's a pain, I honestly can't tell you if the hose will compress or stretch enough to jump between sizes, however another option is to loop between the feed and return ports and live without a heater for the time it takes to get the replacement lines.... assuming the ports are the same size there.

Except the one line has a Y to the coolant recovery tank. There would be no safety valave in the form of the cap.

 

[KJowner]

Except the one line has a Y to the coolant recovery tank. There would be no safety valave in the form of the cap.

That's annoying!

 

[GitEmSteveDave]

Woo-Hoo!

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Part arrived today, and I have all day tomorrow to work on it. Given the small leak, I only lost about 1 gallon of coolant over the course of a few days, and my temp never went above 206F, so I'm pretty sure I'm safe. I am kind of pissed that the part was sent w/o a box, but I don't seem to see any damage to the aluminum lines.
In hind sight I probably should have ordered some spring clamp pliers when I ordered the part, given how many there are on a Libby, But I've been lucky to have had success with a pair of needle nose vice grips when it comes to sliding them on and off.

 

[GitEmSteveDave]

Put the line in today. Word of advice to anyone attempting this, remove the air filter housing and you will have a ton more room to work with and you really can't get the lines in or out w/o doing it.

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I should have also ordered a set of spring clamp pliers and also a 3/8" drive 8mm hex socket to loosen the bleed screw because my pocket hex key set can't handle that torque. As for the leak, as soon as the new one was in place, I figured out what happened. The plastic standoff on the front of the engine had been removed some time in the past and allowed the metal hose to make contact with the valve cover. After a bunch of years, this was the result:

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A less than 1mm hole that was drooling coolant onto my manifold.


But with the new line in with the plastic standoff, I think it will outlive the rest of Libby.