Broken Petcock in Engine Block WWYD?

[redm18]

Greetings I will post a picture below. I recently purchased a late 80's Kubota 4200 HST garden tractor. It has a Z430 diesel engine. As part of putting it into service I have been changing fluids and other items on the book maintenance schedule. Last night I went to change out the coolant. It has what I assume was an aluminum petcock on the block to drain the fluid. I turned the petcock and noting came out. The petcock fitting had a hex head on it so I tried turning it with a socket. It broke off super easy. Still no fluid. I change. I changed the fluid by pulling the radiator hose. I'm trying to decide what to do now. 1. Leave the broken off fitting and hope the very hard corrosion/ crud holds the fluid in forever and keep an eye on it. 2. Try to drill out the fitting with a hand drill, tap it and put in a bolt or something to seal the hole. 3. cover the hole with some sort of JB weld or something similar and hope it holds.

 

[redm18]

 

[SteveH-CO]

It may one-day leak, but unless you really need to drain the block with a petcock (vs. pulling a hose), I'd leave it. I'm not sure covering it with JB Weld would add any leak resistance.

Another option is to just drill it out, tap with an NPT tap, and install a pipe fitting with a plug (coated with anti-seize compound).

 

[RPH]

That’s a tough one. I suppose physical access is part of the problem?
Number one leaves chance to work for or against you. Doing nothing is easy. I find when choosing this option it turns into a quagmire. It goes down the rat hole right when you need it most.
Number two, if drill access is available and you are confident of your skills, I would attempt the left hand drill option. Start small and continue to expand the hole. If lucky the heat, vibration, and the cutting edge of the drill bits spins it out. Best scenario in this case.
Number three, about the same as number one, it easy and it might work for awhile. But in the end it will fail as time is not on it side. Failure occurs when you need it most and have the least amount of time to correct.
It’s in for maintenance and this is maintenance. I would fix proper and eliminate the concerns.

 

[quickfarms]

I would talk to the dealer mechanics or a local mobile mechanic to get there advice

I would also get the replacement part so you can see how it is constructed and what the thread is in the block

It looks like the block is steel so it would be stronger than the aluminum

 

[txvwnut]

If it was a standard twist type petcock like on the bottom of a radiator leave it. The part you turn is threaded as well and has to be turned into the block to open it. Since its seized on the thread's it aint going anywhere. If you want a little piece of mind you could smear a little JB Weld on the silver part and let it run.

 

[GreenIron]

If it were mine, I'd drill it and use an easy-out to remove it, then replace with another pet ****. It most likely has pipe threads so a pipe plug with a Teflon sealer will work also.

 

[m6z]

I'd leave it alone.

I don't think I've ever used a petcock to drain fluid, I always just pulled a hose since petcocks are notorious for snapping off.

 

[Jwallace1]

if it was me i would drill it out and take the opportunity to do a good flush on the system, tap it to the next size up NPT and thread in a new petcock, i always install them if the block has drain points saves a lot of mess and have never run into issues with them.

 

[Wrench97]

I would not touch it unless it starts to leak, in all probably you got another 10 years+.
If it really bugs you drill and use a easy out to try and unscrew, if that does not work grind a hacksaw blade down to fit in the hole you drilled and saw a couple cuts in a pie shape then use a small chisel to remove the pieces clean up with a tap.
Drilling oversize can be risky castings are not always the same inside and out there may be less material then you think on that boss.

 

[claymont]

If you're thinking about using something like JB Weld to try to seal it, do it now before it starts to leak and the area gets wet. Clean it up with a little emery paper and smear it on.

 

[The Cobbler]

that's a tough call . it's probably OK to leave it & keep an eye on it for seeps which could lead to worse

 

[zkdiesel]

I would not touch it unless it starts to leak, in all probably you got another 10 years+.
If it really bugs you drill and use a easy out to try and unscrew, if that does not work grind a hacksaw blade down to fit in the hole you drilled and saw a couple cuts in a pie shape then use a small chisel to remove the pieces clean up with a tap.
Drilling oversize can be risky castings are not always the same inside and out there may be less material then you think on that boss.

This. Leave it alone. As soon as you twisted the first part off you should have stopped

 

[paulsomlo]

I had a similar situation with a Honda Civic - wanted to drain the block using the drain plug, but it wouldn't budge. I used a wet/dry vac to **** out the remainder of the coolant after removing the hoses.

 

[mervyn]

Sprinkle some Holy water on it and leave it alone is what I’d do. Good luck -

 

[dkmc]

I'd drill it out and re-tap it. I'm a machinist.

 

[Rgrigutis]

Leave well enough alone. Easy to eyeball occasionally