Topic

Thought I would slacken the bleed screw for the heater ready, to fill coolant system ( once I knew which fluid to use) Guess What? the thing has sheared so now need ideas on how to remove heater unit or any other ideas to solve problem
only thing is I don't think the bleed valve moved at all so it may still be sealed but not sure if leaving it will cause heating problems HEEEEELP

it's essential to bleed the system at all three points after refilling the system.
You may have an air lock otherwise which can cause serious overheating problems when it reaches the wrong point in the system.

Do you have a chance to weld on another head an top or to cut a furrow to apply a tool?
Give it a good soak with WD40.

EDIT David Aiketgate added:-

Use a penetrating spray rather than WD40 e.g. Plusgas. It's much more effective!

As a quick fix just disconnect the hoses from the heater and cap them.

Yep sounds like you are up




Can you drill a hole in it and use a screw extractor / easyout ??

http://www.the-t-bar.com/forum/tooltime/90572-screw-extractors

Hope that helps. Let us know how it goes.

What the 3 guys above said and some pics of your problem might help us to help you better.

worth buying a small left handed drill bit sometimes the action of carefully drilling the hole will ease out whats left of the screw

Invalid or non-existent item ID.The bleed nipple is a standard M8x1.25 pitch (metric coarse) and the tapping size for M8 is 6.8mm so if you are drilling don't go over that size.

As mentioned in previous posts soak in some penetrating oil, try Easy Outs with LH drill set as per the link below:
http://www.axminster.co.uk/cobalt-drill-easy-out-set?gclid=Cj0KEQjwgryfBRDn7cvY-pOit4cBEiQAB3nTbmROkA5xORLI78hbZV1FPDy732g5Ek8QigwevIrzKtEaAots8P8HAQ

If you manage to get it out the part number for the bleed nipple is JHN100010 or fit a stainless one (less chance of it rusting in) plenty on flea bay link as below:


Hopefully you'll get it out but if not you will have to remove/replace the matrix, the only consolation is they are very cheap from the breakers.

Good luck.

Brian.

Thanks for all your ideas have managed to drill and extract (with stud extractor) out the broken part then re-tapped out the thread but as this may not be a tight fit had a friend make up a small extension which I intend to screw and seal in place, then fit a new Bleed screw/nipple into the short extension (made from Stainless steel) so easier to get to and no more Seizing of the bleed screw.
Please could some one clarify, I thought the correct size for an 8mm tap was 6.9 but note in one comment a size of 6.8 was recommended (having just ordered a pack of 6.9mm Drills)

Its great you got it sorted.

https://www.carbidedepot.com/formulas-tap-metric.htm

Davem wrote: wrote:

Its great you got it sorted.

Yep, it's great that you've sorted the problem out. Some pics, if you can, might help others who get the same issue. Also, we'd like to see your ingenuity.

BSI / ISO standard tapping size drill for M8 x 1.25 pitch is 6.8mm as per my previous post. Your 6.9mm drill is only 0.1mm bigger which is just under 4 thou (0.0039") and will make no noticeable difference after tapping out just for a bleed nipple.

Brian.

Thanks to ALL members for your help am now ordering 6.8mm drills (will save the 6.9mm already ordered for some future job) as I want a tight fit for the bleed screw (coated with copper slip) and place a copper washer between the old bleed screw fitting and my short extension.
Once again THANKS! will post Pics as soon as I have tapped out for bleed screw and finished job.