Broken oil pressure sending unit - HELP!!

[jeffncs]

I F’d up…. To be more clear the previous owner of this engine left me an Easter egg that I just found….

Found the source of a nagging oil leak on my wife’s 70 (I built it for her). Source = the extension that threads into the block for the oil pressure sending unit.

I think the PO used loctite or some other sealant b/c the stem spun off leaving the threaded nipple flush to the block.

I pulled the PS pump and fuel pump. I’ve tried increasingly larger EZ Outs, heat, PB Blaster. The nipple isnt budging.

Any suggestions? I’ve been on this thing for hours - broke 2 wrenches, 1 socket and my tap adapter.

I’m running out of options before throwing in the towel.

 

[73azbronco]

drilling, but, might try some heat and keep with the easy out, might have used jb weld for the win.

 

[Oldtimer]

The piece that broke off is steel, brass, or aluminum?

 

[Lawndart]

Happened to me last year.
Take a look at this thread - https://classicbroncos.com/forums/threads/broken-oil-sender-extension.324762/

Short version - get a set of "square" extractors and don't waste your time with other types (I purchased mine from NAPA) - https://classicbroncos.com/forums/threads/broken-oil-sender-extension.324762/post-3557573

I bought a steel extension replacement from https://www.northeastclassicfordparts.com/

Best -o- luck.

 

[jeffncs]

The piece that broke off is steel, brass, or aluminum?

Aluminum

 

[jeffncs]

I ordered a set of the square extractors through Amazon. GearWrench brand. Fingers crossed they work!

Soaking in PB Blaster until they arrive.

 

[jeffncs]

Just an idea of the square extractor doesn’t work…. What if it tapped the oil port hole and ran a bolt with red thread locker? After it set up, I would think the nipple would turn out with the bolt.

I’ll be approaching desperate mode if the different extractors don’t work.

Worst case is it acts like a plug and I don’t have an oil port (gauge doesn’t work anyway!)

 

[Jdgephar]

If it's still centered, you can also try a left-handed drill bit. Worst case, drill it out, tap it with a larger size and run an adapter?

 

[jeffncs]

The nipple chunk laughed at the 2 left-hand drill bits last night - didnt budge! I really think PO used plumber dope (hardening kind) or thread locker. I guess I’m just stepping up the bit size to tap the hole….

This sucks though.

 

[ksagis]

Heat seems like a good idea except for difference in thermal expansion resulting in the aluminum expanding more than block and maybe getting tighter.

Good luck when you get the square extractors.

 

[pcf_mark]

That is such a bad spot to work too. This video example is above the surface but I used the same on an aluminum head with a flush broken stud it worked. The welding heat is what really got it loose.

 

[ksagis]

Heat is definitely a good tool to help break things loose. If the stud is steel and the head is aluminum the CTE is working in one's favor.

I also thought of one of those old school impact hammers that you hit with a hammer to jar things loose. Could maybe chuck an extraction bit and get some extra pop to help it break free.

 

[jeffncs]

Sadly the square extractor was a fail. Just bought a bit and 1/4NPT tap. Nuclear option…

 

[DirtDonk]

It’s certainly possible that a previous owner put something in there, but it’s also possible that the aluminum versus cast-iron is creating a reaction in between.
Those things have been breaking and leaking since the late 60s!
Mine had already been replaced with a piece of round tube when I bought it and it was only five years old at the time.
Whenever I’ve known someone who has removed or replaced one of the aluminum ones, it has broken, probably 90% of the time.
So at least in your misery, you’re not alone!
Not much relief in that knowledge, but you’re not suffering alone.

 

[Lawndart]

Sadly the square extractor was a fail. Just bought a bit and 1/4NPT tap. Nuclear option…

Dang - that blows.

 

[ksagis]

Have you tried heat yet like pcf_mark suggested? I’d give it a whirl before drilling and tapping.

Torx bits sometimes make good extractor tools too.

I despise NPT…

Edit: I crawled under my truck and saw aluminum and made a mental note for future

 

[jeffncs]

Heat didn’t do it. I ended up buying a bit/tap set. Drilled snd tapped. All done. What a terrible design!!

I’ll purge it tomorrow with my priming dizzy and get it back together.