bullitt Posted October 1, 2014 Report Share Posted October 1, 2014 could anyone enlighten me as to how to remove a siezed piston from the engine block..I have been able to remove 2 of the connecting rod caps and bearing shells but because of the position of the crank I cant get to the other bolts to remove the remaining caps and shells.Short of wolloping it with a piece of timber and a lump hammer to loosen it im bit lost.... knowing my luck I.l probably bugger the crank.....Any help would be appreciated......Many thanks....frank Quote Link to post Share on other sites
Damson6 Posted October 1, 2014 Report Share Posted October 1, 2014 (edited) I seem to remember someone using very hot paraffin/oil mix pouring it in and soaking the bore with it Edited October 1, 2014 by Damson6 Quote Link to post Share on other sites
TR 2100 Posted October 1, 2014 Report Share Posted October 1, 2014 I don't see clobbering the piston with a heavy hammer, with a block of wood in between, is going to damage the crankshaft. Pretty much standard practice. Give it a really good soaking first - don't be too impatient. Various concoctions, one of which is described above. Obviously make sure the con rod ends with the cap removed is kept clear of the crank when you bash the piston down. AlanR Quote Link to post Share on other sites
bullitt Posted October 1, 2014 Author Report Share Posted October 1, 2014 Trouble is alan I managed to undo 2 of the conrods from the crank but there are still 2 connected and I cant get to the bolts because of the crank being held by the seized piston in the wrong position...... should I remove the rear main bearing cap,the front sealing cap and the centre main bearing cap and then go for the big hammer and block of wood remedy....I.E. (the fine adjustment tools)...frank Quote Link to post Share on other sites
bullitt Posted October 1, 2014 Author Report Share Posted October 1, 2014 Thanks derek....got the piston covered by bout 20 mm of WD40 in the bore at the moment...have done for bout 3 days but doesnt seem to be doing much good so may have to try your alternative method.....thanks for the help....frank Quote Link to post Share on other sites
ChrisR-4A Posted October 1, 2014 Report Share Posted October 1, 2014 Try some genuine pentrating oil, it works wd40 does not! Chris Quote Link to post Share on other sites
Motorsport Mickey Posted October 1, 2014 Report Share Posted October 1, 2014 Use diesel dear Frankie, dear Frankie, dear Frankie...use Diesel. Much better than WD40. Mick Richards Quote Link to post Share on other sites
stargazergs Posted October 4, 2014 Report Share Posted October 4, 2014 I'm with Mick in this one diesel is the way to go, it's been tried and tested method for a millennia for freeing off siezed pistons. flood the barrel/bore with as much as you can and let it work it's magic, and you should be able to work it free. Gavin Quote Link to post Share on other sites
Kiwifrog Posted October 6, 2014 Report Share Posted October 6, 2014 WD 40 is great to polish rubber hoses or drive damp from eletrical connections but sod all else, find some diesel or plus gas cheers Alan Quote Link to post Share on other sites
RogerH Posted October 6, 2014 Report Share Posted October 6, 2014 Hi Frank, don't undo any of the crank bearings. These will support it whilst you are attacking the piston. Has the piston seized in due to corrosion. If so then a proper penetrating fluid (plus gas etc). WD40 is used to take up space on a shelf. Diesel is the alternative evil brew that works. Using a decent lump of wood on top of the piston give it a good whack with a very large hammer - 5+lbs. It will not move far with one hit so keeping the other rods out of the way is easy. If the piston has seized due to lack of oil then it may well be anchored more tenaciously. Do much the same as above but hit it harder. Roger Quote Link to post Share on other sites
AlanT Posted October 6, 2014 Report Share Posted October 6, 2014 I hate to hit anything but you will wind up hitting this. When I hit something I plan carefully how I hit it. In this case you want a block of alloy that sits on the top of the piston. Forget about wood. You hit it with this: https://flic.kr/p/nNLfA7 4lbs of lead. Take two hands to swing. This is a "dead-blow". Its quite different to a steel hammer that rebounds. Normally I swing it about 8in! You would be surprised what will move with just a small blow like that. Its about tranferring energy from motion into a sudden shock. Quote Link to post Share on other sites
stillp Posted October 6, 2014 Report Share Posted October 6, 2014 While I sympathise with the view that diesel is a better freeing fluid than WD40, please remember it is carcinogenic and mutagenic. Wear nitrile gloves, or use a purpose-made pentrating fluid. If you want to try something designed for a diffferent purpose, try a cheap coca-cola, the phosphoric acid will free parts seized by rust, and it's cheap from one of the discount supermarkets. You probably need a turning force on the crank while you're hitting the piston. Quote Link to post Share on other sites
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