Broken temp sender - frustration!!!!!

[abri]

When trying to remove a wrong temperature sender from a head I have had trouble to the point where I don't know what to do anymore. Firstly, the head of the temp sender stripped. I then tried to hammer a one size smaller socket onto it so that the socket cuts into the soft brass and to turn it like that. No success. I then borrowed an impact driver and using the same socket, tried that, nothing. I then got desperate and tried gripping it with a vice grip, with the expected results. The head of the sender is now completely f**ked. This allowed me to remove the interior of the sender, leaving a perfect hole to screw in an "easy out". This I have tried but the sender won't move. I am afraid of breaking the sender off inside the head and having to drill it out because to get the pieces out of the waterways would probably mean removing the head. I have now taken a break to ask for advice.

If anyone has had similar experience I would really appreciate ideas.

[COOPERCO]

If you do end up drilling the old unit out. Before getting the drill out, drain the coolant level down, remove the top hose/thermostat housing & thermostat. You should then be able to retrieve the bits & pieces (or most of them, grease on a screw driver etc). If you can carefully go up size by size with your drills you should be able to get to a point where the thread only is left & may be able to get it out with a pick/scriber.

Mike.

[abri]

Great, thanks Cooperco. I was uncertain whether the sender is visble/reachable through the thermostat hole. If it is, then as you say, careful drilling is a much more attractive option. I'll give that a try tomorrow.

[abri]

Ok, I have now managed to hollow out the temp sender to the extent that it forms a brass sleeve of about 1mm thick inside the temp sender hole. The aim was still to try and preserve the original threads by not putting in a drill that is too large. I've taken off the thermostat housing and thermostat and I've knocked off (and retrieved) the rear section of the sender that protrudes into the thermostat chamber. I've tried using my easy out again but its like the brass has become part of the head....unf**kingbelievable!

It looks like I will have to tap new threads if I'm going to drill any further. Two questions:

1) What is the correct size tap to use for the standard temp sender hole?

I read here http://www.minimania.com/MM/Mini_FAQ_Part_2.htm that it is 5/8 BSP. Can anyone confirm this?

2) Having never tapped thread on the inside of a hole before, can I use a smaller tap to try and break the brass up and then a larger one (5/8 BSP) to restore the original thread?

Any help will be much appreciated.

[mascher]

Try running a left-hand drill bit through it. There's a very good chance that the rest of the brass will come out.

Kelley

[66S]

An Easy-Out is probably the worst thing you could have used because it expands the brass and makes it even tighter than it was. If you don't want to drill it, try cutting it lengthwise with a saw blade so that the thread tension is released.

Regards
Al

[abri]

An Easy-Out is probably the worst thing you could have used because it expands the brass and makes it even tighter than it was. If you don't want to drill it, try cutting it lengthwise with a saw blade so that the thread tension is released.

Regards
Al

Thanks! Yes, the easy out did probably cause the brass to stick even tighter. After hollowing the brass out to about 1.5mm I started getting very worried that I might damage the threads. I then used a small screwdriver and a hammer to chip off and cut out pieces of brass until the stress was released and I could start getting a bit of movement. What a nightmare. Such a simple job normally. Luckily I didn't damage the thread and the replacement screwed straight in WITH some lubricant this time!