Help with a small coolant leak

[Dutch Rutter]

Starting to sound like a broken record with these leaks. This one is with the coolant system.

I recently replaced, Water pump with a "severe duty" pump from the local parts store. Also replaced the clutch fan with a matched severe duty one, replaced the old style coolant overflow bottle with a new style one, and lastly I replaced the lower rad hose and rad cap.

What I am seeing now is after parking the truck after a drive, I get some coolant splattered on the ground underneath the passenger side radiator. Coolant level seems fine in both the bottle as well as the radiator. Everything has tight clamps on it, and this only seems to happen after driving the truck.

This leak was happening before all of this work, I thought it was due to the old style of coolant bottle which I am sure was contributing to it but not the only cause. This is also a newer plastic side cap style radiator.

Anyone else experience this before? I have ran out of ideas and might just take it to a local radiator shop to be checked over.

edit: a shot of the new coolant bottle, because everyone loves pictures.

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[Charlie]

Pressure test of coolant system should show where the leak is. IMO

 

[Dutch Rutter]

Pressure test of coolant system should show where the leak is. IMO

This is what I was thinking myself. but I don't have a pressure tester so local shop it'd be. The only spot that I am seeing of a possible leak is from under the radiator cap. Kinda like the coolant is defeating the caps seal if that makes any sense.

Since everything is full and I only have a leak after the truck is stopped from being driven I would not think it to be a crack or leak in the radiator itself, but I could be wrong. I'll plan on taking it in to get checked out. But I have a feeling its something small, like I got the wrong cap for it or something like that.

 

[Crispy]

I just recently went through something similar with my Ram. Turns out I had a pinhole leak in the radiator core. I'm talking about tiny. I drive 130 miles a day and it would take a week to lose enough coolant from the overflow to notice. If you are losing coolant externally theres a hole somewhere.

Now our squares have an A size radiator cap and I found that the tester rented from Advance Auto didnt have the right cap adapter. I bought the following tester since I felt I needed one in my tool arsenal and 4 out of my 5 cars use A size caps.

https://www.amazon.com/Stant-12270-...r=8-3&keywords=stant+radiator+pressure+tester

Also note, for whatever reason sometimes the pressure tester would hold for 30 mins, sometimes it was losing pressure within 3 minutes. By dum luck I found the hole right above the front bumper reinforcement. I mixed up a bit of JB weld and covered the hole until spring time when I can buy a new $350 radiator.

 

[Dutch Rutter]

I just recently went through something similar with my Ram. Turns out I had a pinhole leak in the radiator core. I'm talking about tiny. I drive 130 miles a day and it would take a week to lose enough coolant from the overflow to notice. If you are losing coolant externally theres a hole somewhere.

Thanks Crispy, I should buy a pressure tester here in the future, and for the price of that kit it'll be WELL worth it. I'm just kind of over pulling my hair out about these things. I got an appointment after work today for the local radiator shop. They said if its something small $50 and I'll be fixed up. I figure if this aftermarket 3 core radiator is shot. I'll end up replacing it with a new 4 core and be done with it. Probably not a full aluminum one but we'll see come pricing time. after thinking about it I am betting there is a pin hole or small crack but near or in the cap neck.

I do have a stock (brass side caps) HUGE radiator that I pulled from my 86 3/4 ton 6.2l C20 before I sold it. But, If I were to put that in here I don't think my coolant would get hot enough for my heater to work. So that'll stay on the shelf until after I do some kind of big block swap.

I'll post back after the appointment.

 

[Charlie]

Check out youtube for pressure testing. I saw some ways of pressurizing without the special gauge set. Homemade styles.

 

[4WDKC]

I just recently went through something similar with my Ram. Turns out I had a pinhole leak in the radiator core. I'm talking about tiny. I drive 130 miles a day and it would take a week to lose enough coolant from the overflow to notice. If you are losing coolant externally theres a hole somewhere.

Now our squares have an A size radiator cap and I found that the tester rented from Advance Auto didnt have the right cap adapter. I bought the following tester since I felt I needed one in my tool arsenal and 4 out of my 5 cars use A size caps.

https://www.amazon.com/Stant-12270-...r=8-3&keywords=stant+radiator+pressure+tester

Also note, for whatever reason sometimes the pressure tester would hold for 30 mins, sometimes it was losing pressure within 3 minutes. By dum luck I found the hole right above the front bumper reinforcement. I mixed up a bit of JB weld and covered the hole until spring time when I can buy a new $350 radiator.

$350, what so special about this radiator that makes it worth it? I know they arent cheap I have one from Dewitts for my corvette but one for a truck shouldnt be that expensive.

Thanks Crispy, I should buy a pressure tester here in the future, and for the price of that kit it'll be WELL worth it. I'm just kind of over pulling my hair out about these things. I got an appointment after work today for the local radiator shop. They said if its something small $50 and I'll be fixed up. I figure if this aftermarket 3 core radiator is shot. I'll end up replacing it with a new 4 core and be done with it. Probably not a full aluminum one but we'll see come pricing time. after thinking about it I am betting there is a pin hole or small crack but near or in the cap neck.

I do have a stock (brass side caps) HUGE radiator that I pulled from my 86 3/4 ton 6.2l C20 before I sold it. But, If I were to put that in here I don't think my coolant would get hot enough for my heater to work. So that'll stay on the shelf until after I do some kind of big block swap.

I'll post back after the appointment.

Any reason you cant buy an aluminium swapmeet special one NIB for 100-150 and make it work? They come in sizes up to 31" iirc.

 

[Snoots]

I do have a stock (brass side caps) HUGE radiator that I pulled from my 86 3/4 ton 6.2l C20 before I sold it. But, If I were to put that in here I don't think my coolant would get hot enough for my heater to work. So that'll stay on the shelf until after I do some kind of big block swap.

If it were me (and I know it ain't), I'd spend my money having the HUGE radiator serviced at the rad shop and install it. With the right thermostat you shouldn't have to worry about it getting hot enough for the heater to work. Time and money saved for better things.

 

[Dutch Rutter]

$350, what so special about this radiator that makes it worth it? I know they arent cheap I have one from Dewitts for my corvette but one for a truck shouldnt be that expensive.

I think that was for the dodge mentioned in the post. Maybe a diesel for it to be that much? I know the after market aluminum ones for our squares can be had online for <$200

@Snoots that very well might be the way i go. Better and bigger rad for cheaper does sound good. Before shelving that beast i had it worked over, one of the caps had a blockage, then I just never put it back in that c20 before I got my k20 and sold the 2wd.

 

[Craig 85]

Here's a cheap way to see where coolant is coming from. I recently did this with my truck after getting the engine installed. I had one of those pet urine detector flashlights (black light). I waited till dark and was able to see where my coolant was weeping from. My block is black, so it made it easy.

 

[Snoots]

I don't think my coolant would get hot enough for my heater to work.

I would think a thermostat that's stuck open would cause that.

 

[Dutch Rutter]

I think your exactly right Snoots.

So, just had the shop do their test and they found it had worn a small hole just below the lower rad hose outlet. Then they quoted my $780.00 for a new plastic cap radiator and a reverse flush.... I paid them their $50 diagnostic fee and quickly walked away.. I'll get this handled and for MUCH cheaper then that. Summit even sells the classic OEM copper/Brass 4 row ones for $414 but instead I'll be installing this big one and call it good.

 

[Snoots]

DAMN! Were you wearing a silk 3-piece suit when you walked in?

 

[Dutch Rutter]

DAMN! Were you wearing a silk 3-piece suit when you walked in?

I wish. Maybe I could have traded it for them to do the work. So figure $200 of that for the Radiator itself, and what $500 for a flush then the remaining $80 for coolant.. Won't be going back there in the future.

 

[Charlie]

Won't be going back there in the future.

My thoughts too!!! If you need a shop in the future, search for a different one.