1994 K2500 Suburban radiator leak at engine cooler line

[tp85]

Hi All,
I have a 1994 K2500 truck which has a coolant leak where one engine
oil cooler line connects to the radiator. Driver's side, upper
connection. These are the oil lines that often need replacing due
to the rubber eventually giving way to a leak in winter months.

There are two seals at this radiator connection. First, there is an
o-ring (~1/2 inch diameter) to seal the oil line to the cooler.
Second, there is a seal or gasket (~1.25 inch diameter) that somehow
seals the coolant via a large thread/nut combo. I can see the nut,
but not the gasket. This is the gasket/seal that is leaking coolant
on my truck.

Several GM parts guys have claimed that this gasket/seal is not
servicable or available! Any ideas on getting this gasket? Is it
internal or external to the radiator? I hope I don't need to buy an
entire radiator.
Thanks.

 

[HarryH3]

The seal between the cooler and the radiator housing is inside the radiator. /forums/images/graemlins/frown.gif But I can tell you from experience that the plastic side tank on that side (drivers side, correct?) is due to fail any day now anyway. /forums/images/graemlins/yikes.gif It's hard to see with the radiator in the truck, but the front side of the plastic tank, directly where the hot water coming from the engine splashes against it, it getting swollen and will soon crack. It usually happens between 9 and 11 years of age. /forums/images/graemlins/angryfire.gif

A new radiator for our '94 1500 Suburban was gonna cost around $350. /forums/images/graemlins/yikes.gif I removed ours and took it to a shop that took off the bad tank (the one on the other side doesn't see anywhere near as much heat, so it should be fine) rodded and cleaned the radiator, and installed a new side tank for $120. The seals for the oil cooler to radaiator housing came with the new side tank.

The plastic tank on our '91 S-Jimmy also split at the exact same spot, right at about 11 years old. But a complete new radiator for it, with both the tranny cooler and oil cooler was only $140. So I just replaced that one! /forums/images/graemlins/wink.gif

Oh yeah, you mentioned the ubiquitous leaky oil cooler lines... Don't bother buying new oil cooler lines from GM. The "parts counter" lines start leaking WAY earlier than the orignals did! /forums/images/graemlins/angryfire.gif Remove the lines and take them to a shop that makes hydraulic hoses. They can cut off the leaky GM hose and fittings and replace it all pretty cheap. Cost me $28 to have both lines repaired for our '94. /forums/images/graemlins/thumb.gif GM boned me for over $90 for new lines on the S-Jimmy and a year later one of them had already started leaking. /forums/images/graemlins/angryfire.gif I did have to pay something like $1.50 each at the GM dealer for the little O-rings that seal the ends of the lines to the engine and cooler though. /forums/images/graemlins/frown.gif

 

[tp85]

Thanks for the warning about the splitting tank. I will take a closer look...although it sounds like I have to replace the tank anyway to stop my gasket leak.

Yeah, I've replaced the oil cooler hoses twice. The first replacements only lasted about 1.5 years! Made in China sticker noticed on the second replacements. Next time I will do what you recommended at a hydraulic hose shop.