Removing Seized Pistons

Testacalda · 21-08-2020 4:52pm #1

Have a job on at the moment to try and get an old 3 cylinder diesel running. Pistons are seized bad enough. Got me thinking, what in your opinion is the best liquid to help un-seize the pistons or leave sitting in the bores.

I've heard so many suggestions over the years, Diesel, ATF, WD40, brake fluid etc... Love to know what your approach is.

Con rods aren't attached just in case anyone is starting to wonder :rolleyes:

kadman · 21-08-2020 5:28pm

I think I have used all you mentioned and more down through the years for seized pistons.

Back in my day the choice of new specialized chemicals was virtually non existent,
now you have all sorts of choices of amazing liquids.

But strangely enough the most recent seized engine item I had to tackle was a seized
injector. I tried all the usual over a few days, and nothing shifted it.

So I had to resort to coke..........not sniffing it, but good old original 100%
unadulterated original sugar laden coca cola.

I came across the idea on the net, and thought what the hell, I'll try it.

And it worked for me

21-08-2020 5:41pm

I've never had to deal with this but would freeze spray help?

two wheels good · 21-08-2020 5:58pm

Plus Gas
But they don't look too bad. Are you sure it's the pistons are seized?
I've read a mixture of acetone and ATF is supposed to be effective.

Tazio · 21-08-2020 7:39pm

I've used ATF - left to soak for a while on an old engine in past-

from the photo you're in deep

so if you're pulling out the crankshaft then a few taps of a 2x4 on the piston face may work too.

Standard Toaster · 21-08-2020 7:42pm

A few clatters from a Nokia 5110 should shift 'em. :¬}

I heard the aul lad mention Coke being used too.

kadman · 21-08-2020 8:55pm

Put a rusty washer into a glass of coke and see what happens after a short space of time.

You would be shocked, and we drink this stuff:eek:

FintanMcluskey · 21-08-2020 9:05pm

Is that a 3000 Ford?

I can't see the pic properly on my phone, it appears it doesn't have liners?

Anyway, try to hammer down slightly to break tension, and polish the sleeve until its spotless using emery paper because the rings will be tight all the way up otherwise

LollipopJimmy · 21-08-2020 9:25pm

Standard Toaster wrote: »

A few clatters from a Nokia 5110 should shift 'em. :¬}

I heard the aul lad mention Coke being used too.

He wants to remove them not smash them to smithereens.

Plusgas is good stuff, I've had success with this

RobAMerc · 21-08-2020 11:53pm

I was doing some work on the brakes of my car and tried 4 or 5 different potions after searching the web. I came across the idea of ATF mixed with acetone and it seemed to work the best.
What got me about it, was having freed the offending bolts, I could see it had worked itself into the threads, where as other things such as WD40 was nowhere to be seen once the bolts were free bar on the heads and the floor under it.

Testacalda · 22-08-2020 10:12am

I'll try diesel first and see what happens. Acetone and ATF sounds like a good job though.

The engine was taken apart by someone else, so I'm not sure how bad it is yet, I suspect its just number 1 that's badly stuck. I generally try tap them down, clean the bore, then tap them back up.

It's a Dexta by the way

scannerd · 22-08-2020 12:06pm

watch some mustie1 videos on youtube, he takes this kind of thing on all the time, with no special tools, and might give you some pointers beyond what to soak with

MrCostington · 22-08-2020 7:35pm

Would gently heating the block help?

Testacalda · 22-08-2020 7:50pm

scannerd wrote: »

watch some mustie1 videos on youtube, he takes this kind of thing on all the time, with no special tools, and might give you some pointers beyond what to soak with

I've plenty of experience with jobs like these, was just curious as to what other people used.

My brother actually left ATF in the bores. We tapped the pistons down today without too much effort really. Cleaned the bores with a wire brush on a drill and some 80 grit paper, then tapped them back up and out the top.

Bores are bad enough and beyond reusing. Rings rusted and broken too, so it'll need a full job doing. Mains and big ends are slightly scored too.

Removing Seized Pistons

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