Broken bolt removal

[Seattle Scott]

Well the good news is the heat exchanger core (Yanmar) came out easily and didn't need unclogging ( checked it after reading Mainsails recent post with pics) but I had to move the alternator to slip the core out over the top of it. In loosening the bolt that holds the alternator adjuster arm, I sheered the bolt and I can't see the bolt remaining because it also anchores the freash water pump and the threads start about an inch back from the head. In other words I have an inch long untreaded bolt in my hand the threaded end is back in the block through the hole in the water pump "flange".

In the past with broken off bolt and screw heads, I used the drill and extractor method with one of those "extractors" that sort of look like a reverse thread tap.

Is there another method?

I supose I should take the water pump off first. I just hate when this happens ( A little inspection maintainence) and I break something in the process and the inspection confirmed no maitntainence was needed.

It is pretty slick how the exchanger core slides out of the Yanmar 4JHE and I bet it would have cleared the top of the original alternator, before the Balmer was installed.

 

[Ron20324]

And we assume you cannot get to the back end of the broken bolt?

 

[Maine Sail]

Can

Scott,

Can you possibly post a picture? It sounds like you are saying the bolt broke off 1" inside the threaded hole and that you still have 1" of usable thread??

One trick I now use on rusty engine bolts is PB Blaster and then an electric impact wrench or air where I have access to my compressor. You snap a lot less bolts with an impact wrench due to the hundreds of "impacts" which help break it free. It's too late for that now but consider it in the future..

Be very careful with a drill on a soft aluminum engine block and always use a punch to get your drill centered so it does not wander into the block....

 

[r.w.landau]

This may have been a gift.

It was good that the bolt didn't break on it's own schedule. I bet if you look at the end of the bolt, it may have been cracked and partially rusted/ comprimised before your inspection. My quess is someone already over tighttened that bolt and that it was waiting to break.
To this point easy-outs are still the way to go.
Maine mentioned an aluminum block.... If this is the case and if the bolt was not treated, you will probably end up drilling out the bolt and retapping the hole.
I am sure you will get many replies as how to do that and how to reinstall the new bolt.
I wish you spring,
r.w.landau

 

[Ross]

Go to McMaster Carr and order a left hand twist drill bit of an appropriate size and an e-z out. Usually drilling the broken segment with a reverse twise drill will back it out. PB blaster is a very good addition.

 

[Therapy23]

I have not used this but maybe it will help if it is like R.W. says.

http://loctitefreezeandrelease.com/

 

[ITMaster]

I would tell you to do the same thing Maine Sail has. The PB Blaster isn't the most delictable and aromatic thing you will smell, but it will free up most stuff that is stuck.

 

[paulj]

http://sagaforumet.com/yanmar-manual/4JHE/manual.pdf


Bite the bullet

paulj:troll:

 

[BobM]

Two thoughts.

First, that PB blaster is phenomenal, but removed the fresh coating of Eastwood Rust Encapsulator I had painted my engine coupling with, so be careful of painted areas nearby (perhaps others can confirm / deny whether this is a problem in general or perhaps just specific to the rust encapsulator I used).

Second, that I tried another version of a "freeze off" product (CRC) when I took my coupling apart. It didn't seemed very effective.

Maine just reminded me that I still need to pick up the Ryobi 18V impact gun. I was shopping for one for a while, but hadn't scored one off ebay yet.

Scott, I second the notion that having to deal with a broken bolt when the maintenance you performed proved unnecessary. I have been thinking I should do mine thisi spring, but really don't want to have a problem like you are facing.

However, if it will make you feel better can give the phone number of a friend with a Hunter 37 cutter who had a clogged elbow last year and ended up in a crowded mooring area during a squall with an overheated stalling engine. As I recall, he tried to unfurl his jib and something else happened and the jib got ripped then the jib sheet went overboard and wrapped around the prop. He managed to snag an empty mooring though.

I spoke to him just afterward and told him he had a clogged elbow...which he later confirmed and asked me "how did you know?" I told him that, from what I read on line, it is the single most common problem to cause overheating and that I was surprised (since he rebuilt an atomic four once) he didn't know.

 

[Seattle Scott]

Thanks All

I am hip to PB Blaster, used it to get the flange of the drive shaft a few months ago.

I'lll post some pics this weekend. I have the Yanmar manual which I will consult before removing the fresh water pump, which I think I should do to find out if the other mounting bolts are going to shear.

I will check into an impact wrench since I have a compressor.

Boat's not going sailing for a while even if operational, so might as well plug away at this problem at my leisure.

 

[sailingdog]

Be careful with PBlaster, since it can eat engine seals and gaskets... so be very careful in applying it.

 

[Seattle Scott]

The offending bolt was rusted

I have the fresh water pump off and the other three mounting bolts were pristine and the one the broke off was corroded and I can see where there was leaking /staining on a hose below the offending bolt. Not sure how to do photos, but will attach one of "good " bolt and "bad" bolt, both are 20 plus years old I assume.

Should be some photos also of the heat exchanger core on the Yanmar 4JHE.

Will replace the pump gaskets and hoses while I have the thing off. Must have been a coolent leak contacting the bolt causing the corrosion.

Once I had the pump off it exposed a half inch of the broken bolt, put a wrech on it and it broke off again, flush with the block. Will drill it out this afternoon.

This all started because I had to move the alternator out of the way to slide the core over the top. The bad bolt held the alternator arm.

Anyway, now I know how to remove the pump and inspect the exchanger core, and hopefull how to drill/extract sheered fasteners.

 

[Timo42]

If you add a little teflon sealer goop on the bolts when you reassemble it, you shouldn't have any more trouble with corrosion no matter where the coolant came from. Good luck
Tim

 

[sailingdog]

Highly recommend you use an anti-corrosion, anti-seize compound on any bolts in the future.

 

[RAD]

Before drilling a center hole get a very pointed center punch and try to draw an X on the bolt with a fine Sharpie now give it a good shot with the center punch and you'll be close to center or right on and hope after a day of soaking with PB Blaster it comes out with the easy out.
I have had bolts that looked so bad that the fear of having the easy out doing more harm I would just drill the offending bolt out a tad smaller than its original diameter and then run a tap
I wish you lots of luck with this one

 

[John]

Center punch

If you have to use a center punch, the handiest way to go is to get a spring-loaded punch. Not that costly and well worth the price.

 

[Seattle Scott]

Still stuck

I didn't drill a large enough hole and thought I was going to break the easy out when it wouldn't turn the bolt. Got the bolt "soaking" and get a larger bit and easy out and try again this weekend. In the meantime, I paid a bunch of money to the local Yanmar dealer for new fresh water pump formed hoses and same for the temp sending unit replacment which I broke taking the pump off to get to the stuck bolt.

Jeeze, one step forward, two steps back.

 

[Seattle Scott]

Just saw Mainsails post re Tef Gel on his prop shaft

I have some and will coat the pump bolts before re-installing the pump.