Oil and tranny stop leak treatments like Lucas

[PGG]

My 72 K5 is stock, clean and runs good has a 350/350 auto tranny 104,000 miles.

It was sitting for somewhere between 2-5 years in a building with AC and heat.
The seller said 2 years but the inspection expired in 2011. He had hundreds of cars so I am sure the exact details were not sure to him I know I wouldn't know.

My mechanic said it had a few small leaks oil and tranny fluid but to drive it a few weeks get it hot etc and they might seal up. I know the mechanic really well they are really fair and very good people and mechanics. My question is I know there are stop leak products but assume they are bs or not good to use or they would have suggested to use them. Lucas tranny stop leak has good reviews but who knows if those are legit or not.

Just wondering opinions on this.

Thanks PG

 

[livid4dirt]

With a truck that nice, i would bite the bullet and do a re-seal on what is leaking. Just my 2 cents.

 

[PGG]

I am not at all apposed to that just the mechanics good ones said drive it a little see if it seals up. I am doing as they said but thought if there was a good product it might help their plan and keep my garage floor clean.

I am not going cheap on this I promise. PG

 

[dyeager535]

While not exactly the same thing, I had a hydraulic bottle jack that wouldn't hold pressure. Put a bunch of silicone in it, and the thing started working again. That was years back, and as far as I know, it still works fine. I tried the same thing on a floor jack but that didn't work. Not sure why silicone came to my mind to fix it. Obviously depending on what is trying to be fixed, some fluids would harm and some would help, the manufacturers of these products are not likely to knowingly put stuff in them that would hurt the vehicle.

I have a feeling the products CAN work, but it's going to depend on what they are trying to seal. A hardened rubber seal? Maybe a product out there will work. A hardened valve cover seal that has a piece broken off? Not a chance.

 

[Deuling]

My steering box has leaked since I put it in. I have been adding Lucas power steering stop leak to it for a couple years. It has now had about 6 bottles through the system and thats all it runs on. Still leaking

 

[rampage]

Seals get dry when they sit for long periods without being lubricated from normal operation. Do as your mechanic said and drive it to see if the seals absorb fluid and swell up. If they don't then I'd replace the seals. I don't trust those snake oils, you never know what kind of damage they may cause.

 

[diesel4me]

I have used several of the brand name additives like Solder Seal's "Trans-Medic" and Lucas Transmission Treatment in my automatics and they did help at least slow the leaks down enough to avoid having to pull the trans out to put in a front pump seal,and help stop slippage..but I've been told by tranny rebuilders that a pint of brake fluid will do the same thing ,maybe even work better,as far as softening up an old hardened up seal..

Nothing will "fix" a seal worn out or dried up and cracked though,it might slow the leak down a lot though..

I'd expect any vehicle brought out from long storage to have some leaks,often things like the rear main seal,the transmission tailshaft seal,pinion seal on a diff,will weep or leak some,due to some rust that formed on the yokes and "might" stop weeping after its worn off and shiny metal is again present where the seal rides on it...

I might be considered lazy by some,but I don't mind adding a bit of oil or other fluids to keep things that weep full,it beats having to tear the truck all apart and be without any transportation for a long period of time...
I'm to the point I might get things apart,but not be able to finish the job and re-assemble it again...so I just keep topping the fluids off,and keep an eye on the levels on a daily basis instead..

 

[3MAX]

My understanding is that most of the stop leak products simply increase the swell rate of rubber seals. Same thing for "high mileage" oils - the seals swell more and hopefully squeeze off any leaks. In theory they should work to some degree, but I've been told once you use the product, you should continue to use it - you don't want the seals to swell, then contract again, or the leak could become worse.

 

[76k5blazerr]

I think it all depends on if he's gonna be rebuilding the engine/tranny anytime soon. If you just want to stop/slow the leaks for a year or so till you rebuild them if say go for it, no harm there but I have heard that using these products long term can ruin the seals. That was more for the cheap stuff though. From what I've read Lucas oil products seem to be quality.

 

[Greg Ducato]

I would not use any stop leak products in this trans, it is a last resort measure for the truly desperate and will cause more harm for any good it does. Your mechanic gave the best advice, I would heed it.

 

[cybrfire]

The way the snake oil chemical seals were explained to me, and I thought it made sense,

They cause the seal to swell which stops up the leak but the downside is, there is no guarantee that they will stop causing the seal to swell, until the seal completely fails by either spitting out or turning to jelly and leaking a lot worse. Including all the other seals that weren't leaking before.

At best they are a stop gap measure.