Removing the stuck sump plug on my 156 Twink

[Wooderson]

Does anyone have any experience of sorting this? The damn thing seems to be welded tight and I'm worried about stripping the thread with the force I'm having to put through it. Is heating the plug up with an hot air gun worth a shot or should I just get a local garage to deal with it?

Worst comes to the worst, hypothetically how much of the oil could I drain off by just removing the filter and jacking the car up at the rear? I don't think this would get 100% of the old oil out but it might be worth a shot - any thoughts?

[Avocet]

I'd be surprised if you stripped the thread trying to remove the plug. The bulk of the force you'll be trying to overcome will be betwen the head of the plug and its washer. I'd just use a big bar. You could try tapping it repeatedly with a hammer before you put the bar on. That sometimes "shocks" the bond free. That's assuming it's not been cross-threaded by a previous operative!

Tightening it up again is where they usually strip, and it's easily done! Best to replace the washer each time and not do it up so tight. I use a Dowty washer (got half a dozen from my local hydraulics supply place for a quid). They don't leak at all and you don't need to do them up very tight because the rubber insert does the sealing.

[taznuv]

Or you could just give in and use an oil extractor through the dipstick tube?

[wrinx]

Just give it a go and see what happens. If you do strip the thread there are three options...but I'd be more worried about round off the hole or breaking your tools, I broke a 3/8 drive on the Spider sump, so use 1/2 minimum

- replacement sump, cost will be about £200 for secondhand unit and fitting time, but secondhand unit may be duff too!

- helicoil and new sump plug, about £40-50

- tapered sump plug, available from Alfashop iirc, about a tenner.

wrinx

[alfa145uk]

I had one like this on my girlfriend's Bravo - I couldn't shift it at all and started to round the hex in plug it was so tight. I eventually freed it with a Stilson wrench and miraculously the thread in the sump was fine! Cross fingers, get a helicoil kit ready or be prepared to take the sump off and take it to an engineers.

[correlejco]

Had the same problem on a 156 and on a TS Spider. Firstly, you can't strip the thread by undoing it. If it comes out damaged, it was done by cross-threading or over-tightening on a previous fit. So just pile lots of torque in.

But there's the problem. The hex key socket (I was told some early ones were RIBE sockets - need the correct tool for these) will get distorted and will turn into a circular hole if you apply too much. In this case, try a Stillson wrench on the flange of the plug. Then get more brutal and use a cold chisel on the flange.

Heat will help as it's steel in aluminium. But you won't get any heat in with a heat gun as there are 5 litres of oil to heat up. So just go for a good hoon for a half hour and try again when the engine's really hot.

The sump plug is ridiculously long (about 30mm of thread in a thin casting). Anyone know why?