Hello all! Just became the owner of a very pretty low mile 1985 F250 with the 460. I have a few EFI 460's, but this is my first Carb motor.

I was trying to buy this truck around January, it sold before I could get to it, and the buyer is whom I got the truck from.

He made the mistake of not seeing it run before he purchased it, was seized and filled with water when he got it. He drained the water and old oil, put in new oil/filter let the cylinders sit with ATF/PB in them... nothing. It sat for around 4 months after until I finally was able to buy it.

Was still seized when I got it. Pulled the plug and out came literally close to 10 gallons of water, I think some of his coworkers were not on his good side, so it's possible someone put it in there, as I don't know how else it's possible to get just that much water in, especially in such a short time.

I drained all the water, flushed the pan out a little with MM Oil to get some of the sludge out, and then refilled with oil (15w40 Diesel cause cheap) and replaced filter. Cylinders have had fresh MM Oil in them for a day now, and PB for two days before that. It still will not move, it did move about 1-2cm during some part of my attempts though.

Is there some type of magical mix of fluids that might free this thing? Any specific method on applying them etc? I know most people would just say f-it and swap in a new engine, but I'd really love to see this one run, even if only for a short while. Let's say I only get another 15k miles out of it, well that's about 5 years of driving for me if not more.

Thank you for any help/advice ahead of time.

 

When they are seized that badly, the only thing to do is pull the engine apart and drive the pistons out.

 

A Motorcycle mechanic told me he fills the cylinders with brake fluid. He says it always worked for him. Try to siphon out the water and other fluids from the cylinders. You never know, it might work. Try putting a hinged handle (aka) breaker bar with a socket on the crankshaft with a jack or a ratchet strap holding pressure while the brake fluid is in the cylinders.

 

Also if you do the fluid freeing method aka MMO, PB etc, you will have to do it over a period of time not just a day. I freed up a seized engine before but it toke 4 days of soaking the pistons and rings.

 

Yeah you have to get all the water out and you have to be patient and give it some time using the most aggressive rust dissolving agents you can find. I've seen ATF used and I don't think it's been mentioned yet. Kroil seems to be a popular rust attacker. All the other ones have been mentioned already in this thread. One article I read on the subject mentioned 4 months of soaking. Patience...Lots of it.

 

yeah, I know. Just wanted to get some second opinions.

 

Probably just gonna grab some ATF since it's the cheapest method.

 

There is one other product that hasn't been mentioned, Fluid-Film. It's not particularly expensive and there is a family of products.

https://www.fluid-film.com/products/

Call them and ask for advice on which product they recommend for a seized engine.

The standard Fluid-Film does dissolve rust I can attest to, but I haven't used it to free an engine.