69HO43

I'm talking about these drop in pellet deals. Probably made by Bar's Leaks, but who knows.




GM, and likely others, for years used to toss a couple of these into the system prior to first fill. Probably still doing it today. Probably everyone else did it or is still doing it today.

If you rebuild your engine, install a new radiator, water pump, etc., effectively renewing the system, would you toss a couple of them in as well? I know they did/do it more for insurance because getting them out on the transports as quick as possible without having to fix stuff was the goal, but still. I'm kinda on the fence about it. For one, it obviously couldn't hurt or they wouldn't do it, but two, if you build it right since we don't mass-produce, it shouldn't leak anyway. TBH, I've only used that stop leak once for a pinhole seep far away from home, and although it worked, it always bugged me. I try to avoid it as much as possible.

This morning, I was looking at the 71 PIM and saw that note again about putting a couple in the radiator and jogged my memory.

Opinions/thoughts?

Olds64

I wouldn't use them. I'm surprised that the CSM/FSM instructs to use them.

coldwar

Seems to me I was advised to add them by GM service writer at coolant change interval on my 1996 Aurora. But I can't point to any docs to support this quickly.

69HO43

Note #3 near the bottom of the page says to add the pellets. I know the 5th gen Camaros got the pellet treatment at the factory. Not sure about any oil or anti-foam.

Sugar Bear

Not unless there was a leak. If the leak persisted after a couple of thermal cycles then add a small amount.

matt69olds

Those were required and very common “preventive maintenance” on the early Cadillac 4100 engines.

They do work, and if used properly they won’t hurt anything. They obviously will do nothing for an engine with serious cooling system problems.

rocketraider

I was pretty tight with some of the Zone service people, and you would be amazed at some of the GM recommended "factory fixes" I've seen.

You were military. Last time I looked Bar's Leaks carried a mil-spec ID number.

1970cs

My dad worked at the Reatta craft cente. It was SOP to add them to every car.

Pat

oldcutlass

And yet most of us never added anything but coolant to these old cars for decades. My dad used add a water pump lube in his radiator and use top oils in the crankcase.

HighwayStar 442

As a owner of many 85 Seville and one 85 Eldo.with the Cadillac 4100. Which had an aluminum block with iron heads, With the wrong head gaskets up to the late 1984 4100, It was to seal the head gasket from leaking. not for the radiator. Radiator was the delivery system to seal the head gaskets. Near the end of the 1984 line 4100 (after Vin # that i have someplace) they received the correct gasket for dissimilar metals. I would not use in any car other than late pre 1984 4100.

redoldsman

Barr's Leak has been around forever. I have seen it stop some substantial leaks. I would not hesitate to use it.