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So after 6 years of sleeping in the garage, I finally got the Camaro running again. The main issue when I parked it back in 2020 was it was overheating, Found what looked like a cracked end cap that was leaking coolant. Fast forward 6 years and the LSX shop I dropped it off at checked over the radiator and replaced that rubber plug with a new one, flushed the system and put new fluids in everything. Fired it up and no issues, I took it back home and after driving it around lightly a few times and just feeling the car out I finally opened her up last Sunday for about 20 min. Did some hard pulls here and there but nothing insane, kept my eyes on all the gauges the whole time and nothing seemed out of the ordinary. Parked it in the garage for about 4 days and decided to start it and see how she was doing on Thursday. She idled in the garage for about 20 min and then I pulled it onto the driveway and noticed coolant on the garage floor. Don't know it was from Sunday when I parked it or that 20 mins it was idling. Either way, got under and sure as **** it looks like its leaking from the exact same some spot. Brand new plug and the metal clamp was tight. Previous owner swapped a H/C/I LS2 into it. Not sure on the radiator type but it doesn't appear to be a stock LS1 type considering the drain port doesn't have threads for a petcock. Any ideas?
Original plug from 6 yrs ago. New plug from last week. No cracks or anything.
What kind of a drainplug uses a rubber cap and a clamp? I have a feeling that outlet was designed for some other purpose. I'd suggest changing out the radiator for a proper one.
This reminds me of my throttle body bypass leak. If the inner diameter of that cap doesn’t provide a tight fit without the hose clamp, it’s going to leak. You may need to experiment with different caps.
What kind of a drainplug uses a rubber cap and a clamp? I have a feeling that outlet was designed for some other purpose. I'd suggest changing out the radiator for a proper one.
Only thing is.... the previous rubber cap and clamp worked fine for 5+ years until cracked after sitting for a while. I'll try and see if I can find some other caps with a tighter fitting diameter, if not then looks like a radiator switch is in order.
but if I was broke and had to make it work: pull the rubber cap and wipe it clean using a cloth and brake cleaner, scuff the plastic with sand paper, wipe some RTV on the plastic then reinstall the rubber cap. I’d use a fuel injector clamp x2 instead of the worm clamp. Shouldn’t leak after that.
That's about the most bastardized POS arrangement I think I've ever seen for that function.
Looks to me like that tube thing the cap is on, isn't "part of" the radiator, butt rather, is something some numb-nutz graunched into there in a fit of half-assment. I'd pull that tube out and put a regular plastic petcock in there, as belongs, instead.
"That's about the most bastardized POS arrangement I think I've ever seen for that function."
This^^.
The culprit here is the dickhed at that so called "LSX shop"....
" the LSX shop I dropped it off at checked over the radiator and replaced that rubber plug with a new one, flushed the system and put new fluids in everything."
All that and only at a $100/hr??
That's about the most bastardized POS arrangement I think I've ever seen for that function.
Looks to me like that tube thing the cap is on, isn't "part of" the radiator, butt rather, is something some numb-nutz graunched into there in a fit of half-assment. I'd pull that tube out and put a regular plastic petcock in there, as belongs, instead.
Finally found some time to jack the car up and get under to do a thorough inspection. Soooo it does have a ******* petcock..... on the right side, I apologize if in the pictures you guys though that was on the passenger side. So that tube is part of the radiator but after doing as much googling, youtubing and even downloading the 4,000 page GM service manual, I cant for the life of me figure what the hell that outlet/inlet tube is for. Its been capped off for the last 15 years I've owned it with no drivability issues, so its just a matter of capping it better then the previous owner (Which lasted about 6 years) and the "LSX repair guy" which lasted about 3 days lol.
Left side is the driver side w/ the blank tube. Right side is passenger side w/ the actual drain petcock. There's no threads outside or inside the tube so I know its some kind of hose with clamp that attached there. Hot pressurized liquid w/ a super thin piece of plastic and sharp metal clamp. What could go wrong??? SMH It looks to be a stock 5.7L radiator with the tube circled. I'm assuming something got deleted when the LS2 was swapped into the car.
So this may seen like a dumb idea but could you find a allen head bolt or piece of metal round stock that fits tightly in the tube so when you tighten the hose clamps? the tube can't collapse?
I would use two clamps. I don't use hose clamps like you get at Ace on any of my hot rods. I use fuel injection hose clamps. Don't know if they come it that size but it's worth looking into.
I think that port was used for something on the earlier LT1 cars. Looks like they are maybe only selling one radiator for the entire 1993-02 run now, which would mean that port needs to be capped off for any LS1 application.
It used to be popular to upgrade to the LT1 radiator because it's a slightly thicker core. I think folks have been capping that extra port for years, it shouldn't be an issue if you use a piece of heater hose and a brass plug with two good clamps (that was another popular option years ago to make an alternate drain port). Or if you can find a better fitting rubber cap (I have an HD rubber cap sealing off an unused port on the water pump for my Olds 350 - it works just fine, but the flimsy rubber one that came with the pump leaked in just a year or so).
So this may seen like a dumb idea but could you find a allen head bolt or piece of metal round stock that fits tightly in the tube so when you tighten the hose clamps? the tube can't collapse?
I would use two clamps. I don't use hose clamps like you get at Ace on any of my hot rods. I use fuel injection hose clamps. Don't know if they come it that size but it's worth looking into.
No the tube is actually pretty thick, so its not collapsing at all when tightened with a clamp, its the thin cap he used. Looking at the cap he put on it appears to be a vaccume line cap. Not at all suitable for this much pressure and heat, its a wonder it lasted 3 days smh.
Originally Posted by RPM WS6
I think that port was used for something on the earlier LT1 cars. Looks like they are maybe only selling one radiator for the entire 1993-02 run now, which would mean that port needs to be capped off for any LS1 application.
It used to be popular to upgrade to the LT1 radiator because it's a slightly thicker core. I think folks have been capping that extra port for years, it shouldn't be an issue if you use a piece of heater hose and a brass plug with two good clamps (that was another popular option years ago to make an alternate drain port). Or if you can find a better fitting rubber cap (I have an HD rubber cap sealing off an unused port on the water pump for my Olds 350 - it works just fine, but the flimsy rubber one that came with the pump leaked in just a year or so).
Your right on that one, reading some reviews on Amazon about radiator bypass caps a couple guys mentioned that aftermarket radiators on a lot of older cars come with inlets/outlets for multiple generations that might need to be capped if not needed, . I think my previous owner swapped in the LS2 around 2010 and probly switched from the stock OEM radiator to a new aftermarket one that came with the unneeded inlet. Also based on the picture at the top it looks to be the same shape and size as a Dorman Coolant Bypass Cap that most of auto parts stores carry. I also found the Dorman ones on Amazon, and even though it lasted about 10 years before it cracked, I noticed another one that's offered as high temp and has multi-plied walls and is an inch longer so I can get 2 clamps on it, so I'm gonna give that one a try along with the Fuel Injection clamps that LS1 TJ suggested. I'll report back if its successful.
Pretty sure that's what was on it originally from 2010 to 2020 when it cracked and leaked.
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Why wont the radiator drain plug stop leaking? 
