Temp sender removal techniques

[Linda]

Hello all,
Checked the past posts on the temp sender removal and the tips have been to : use penetrating oil, heat with torch, punch out from backside after removing thermostat & tower, drill out, use a Dremel.
My question is what type of bit for the drill, what type of bit for the Dremel? I need to know what to get for the tools
"Carbide" was mentioned in one post, is this good? Any other technique that might be helpful? .
The sender is really stuck and it already has had step 1 applied to no avail.
Thanks,

Linda

[Nissanman]

I just used a HSS [High Speed Steel]drill bit which was the same diameter of the sensor body.
Outside 1/2 diam. is 12mm, inside 1/2 diam. is 11mm.
Use it in a battery type drill so you can control the speed and cutting action.
Drill from the outside to the inside of the housing, but avoid damaging the threads.
You may need to flatten the sensor with a punch to allow the drill bit to get a start on the cutting.
The sensor is a lot softer than the housing so it should cut out easily.
It removed the majority of the sensor just leaving a little debris.
That was easily picked out with a sharp scraper or pointed scriber.
Give the housing a good cleanup inside and test fit the new sensor before re-mounting the housing to the engine head.
The sensor has to be well earthed to the head to enable the electric gauge to function, whilst the retainer has to be well sealed to prevent coolant leaks.
So you will need to ensure the sensor seats well onto the "shoulder" inside of the housing and is firmly clamped by the retainer and that the threads on the retainer are coated with a sealant suitable for water and heat.
I use a white goop called Permatex High Temperature Thread Sealant.
The tighter the threaded portion is the better chance the retainer has of sealing so avoid damaging those threads at all costs

The sensor [LHS diam. is 11mm, RHS is 12mm] and the threaded retaining collar.

[DaRoaster]

A dremel is best because the flexible shaft allows you to get a better angle on it than a drill. Oh, and forget about using a battery powered dremel, use an electric one with a foot switch. You could also use an air die grinder as long as it has variable speed. Be very careful as you grind away the walls of the old sensor. Do a little at a time and blow the filings away with compressed air. Use the metal file attachment. It looks like a christmas tree. The spherical one will also work. I can't stress enough that you have to be patient with this process. The file attachment can take off a lot of material very quickly. It won't hurt to squirt a little oil in there to keep it from getting too hot and burning out the file. Flush your cooling system afterward. Make sure the thermostat is in good working order.

[Daryl Smith]

Since both methods above also require that you remove the thermostat/housing to clean things up, I would give the punch from inside a try first. It's a little tricky because of the angle, just use a longish punch.

Worked well for me on 2 different heads, and very little mess to clean up afterwards

[Linda]

Trying to just ease this thing out after many applications of PB Blaster but bad luck, the hex head sheared off. After looking at how thin it is I am not surprised. Good news is that it is not leaking. Now I have been told that it needs to be drilled out or "burned'out. This last by JP Deburring Chatsworth, CA. But they want the head removed for them to do it. I'm looking for someone who can do the work with the head intact on the car if possible, as this is beyond my meager talents and I don't want to trash the head.
Anyone have any recommendations or referrals?
And also, has anyone used the replacement parts listed in the Parts Interchange section. I have the Wells TU 62, it is all one piece but I was told threads might be different?
thanks for any help.

Linda

[exit64]

Jeez Linda,
You sure do manage to pick all the hard projects. This is a tough one, especially with the head on the car. You need to drill out the brass sensor and then us a die grinder/ dremel to get the retainer out of the threads. The way I did my head was to use a carbide cutter and start working down the retainer bolt. Once I got it thinned down I could actually use a sharp punch and collapse it in towards the middle of the hole. After some cussing and sweating I was able to grab it with some needle nose and work it out a bit at a time. This is a delicate operation and you don't want to bugger up the head. If this is beyond your skill level, take it to a mechanic that you trust and make it his problem. Might cost you a hundred dollar bill but that is far cheaper than messing up the threads and possibly the head. Good luck on this one.
Mike

[dbrick]

definatly not my favorite repair...I gor very lucky and it came right out on the 1600. Mike's suggestion is what I have done in the past, collapse it and coil it up on itself. It helps if there is some bit of the nut sticking out of the hole. You can either try to split it with a tiny cold chisel, or if a piece sticks out, you may be able to start and tap it towards center. It's tedious, but do-able

If you need to drill it, they make left handed drill bits (not kidding). You need to get it started dead center and drill straight. The threads of the nut are very thin, so you need to work your way up to a bit barley larger than the brass temp sender. If you get lucky with a left handed bit, it grabs and unscrews it. A spiral screw extractor may work too. try them as you drill. If you are not lucky, the sender will spin inside the nut. In that case, I suggest alcohol, for you, not the car.

good luck

[spl310]

Years ago when I was on a pit crew, we had one fail. The nut sheared during the attempted removal. With a dremel tool and a lot of pain, the chief mechanic got it out. If you cut into the threads a touch in one spot, it is not all that critical. He drilled out the sender, then took the dremel to the remains of the nut. Once he cut through one part, he began collapsing it until it came loose, then unscrewed it with needle nose pliers. It took about an hour or so to get it done.

Alcohol was applied quite liberally afterwards (to the mechanic, not the car)

[Linda]

Well everybody agrees on the alcohol anyway.
This should be entertaining!

Linda
68 1600