MTFCA Forum

I'm desperately trying to save the fan pulley/hub for my 1918 engine. The fan blades are junk, but the aluminum pulley is in decent, usable shape. Unfortunately, all four rusty steel screws are frozen solid in the aluminum. So far, I've heated the screw heads with a propane torch (to keep temperatures down), applied a good penetrating oil twice. I've only been working on it for about an hour, so perhaps several cycles overnight will let them break loose. My concern is that there is probably some aluminum corrosion in the mix also. Anyone have any good tricks, or am I going to end up carefully drilling the screws out?

A replacement pulley is over fifty bucks from the vendors, and I'm getting a little shy on cash!

Get a good set of easy outs. Make sure you get the ones with the reversed drill bits.

I have found, most often, if a steel bolt will not come out of aluminum. After a couple shots of heat...more than likely the threads will come out with the bolt.
I have several OE pulleys, if you are interested.
Blades also...
Dave

Well, I found out that a small impact wrench........set on minimum.......will definitely break off a screw head. Dave, I may just take you up on that offer after I try a little drilling tomorrow. I have a set of left hand drill bits that work well in steel or iron, but I have my doubts on this one. Stay tuned!

George,

Send me a PM. I have some nice ones restored, belated Merry Christmas! I hate to see a guy spend more money on propane and part B co payment!

All the Best,

Hank

Your fan & pulley have been "updated" as it should be the riveted fan blades on a steel hub for an '18.

I have found that a bath in good old "Coke a Cola" removed rust / corrosion. Also makes a good bug remover on the windscreen, but keep it off the paint as it also removed paint.

Could take 2 days of cycles.

If you can support the back of the screw area, take a large flat punch, and a big hammer, and hit each screw hard a time or two. You will have to repair the slot for the screw driver, but have seen this work many times. It also works on starter and generator field case screws. Those you hit really hard, and they will come out with a regular screwdriver easily!

Pay attention to what Steve Tomaso says above. You have the incorrect fan. I see the correct ones on ebay all the time.

I have been able to remove steel bleeder post from aluminum brake calipers by heating the post with a propane torch and melting a candle around the base of the post. Allow it to cool some then attempt to remove.

Why would you need reverse drill bits ,A hole is a hole.I never new they made them.What do you gain?

A reverse left handed drill bit will sometimes (if you are lucky) grab and spin out the stuck screw without any further action on your part.

BobD wrote: ↑

Fri Jan 18, 2019 11:26 am

A reverse left handed drill bit will sometimes (if you are lucky) grab and spin out the stuck screw without any further action on your part.

Think you Bob.

BobD wrote: ↑

Fri Jan 18, 2019 11:26 am

A reverse left handed drill bit will sometimes (if you are lucky) grab and spin out the stuck screw without any further action on your part.

There's more to it than that..........the left hand bit "rides over" the threads and doesn't dig in. The result is no damaged threads after the drilling is completed. Usually. If the bit is not exactly parallel to the hole, it can damage them somewhat.

After pondering this thing overnight, I seem to remember that I have a riveted fan with a grease cup on the rear........somewhere. I'll start digging through my rust and see if I can find it. It stood out in my mind because the pulley was steel and had a bullet hole through it. If I can't find it I'll contact one of the members here for a replacement.

Again, thanks everyone!

BobD wrote: ↑

Fri Jan 18, 2019 11:26 am

A reverse left handed drill bit will sometimes (if you are lucky) grab and spin out the stuck screw without any further action on your part.

True, there is more to it than that. Should have added that before one attempts using a left handed drill for broken screw removal it is essential that one have the part rigidly secured, ideally in a milling machine or good rigid drill press and vise. The hole must be drilled as close to the center of the screw as possible. A center punch prick or a center drill is useful for starting the drill in the center of the screw or bolt. I always use a drill that is smaller than the root diameter of the thread so as not to damage the threads. As George pointed out, the drill must run parallel to the screw hole and not wander otherwise damage to the hole threads will occur. Ask me how I know this.

get them hotter with acetylene

I agree with whacking the supported screw with a slotted screwdriver and hammer and I agree with light oxyacetylene application but I’d also add quenching with water. With stuck dissimilar metals after the application of heat, quenching will cause a miraculous ‘let go’ of the 2 stuck parts. Especially works well with cast iron and steel...

George House wrote: ↑

Fri Jan 18, 2019 4:01 pm

I agree with whacking the supported screw with a slotted screwdriver and hammer and I agree with light oxyacetylene application but I’d also add quenching with water. With stuck dissimilar metals after the application of heat, quenching will cause a miraculous ‘let go’ of the 2 stuck parts. Especially works well with cast iron and steel...

You're absolutely correct George.
I have had much less success with aluminum though.
Another problem is that tends to harden the bolt, then trying to drill it is tough. I've rounded off Snappy ez-outs, after heating and quenching.
I have used Torx bits as an extractor before with pretty good luck.

Personally, I wouldn't put that much time into this project, when a replacement is easy to get.

Yeah, you’re right Dave. I have 6-7 of those aluminum fan pullies on a shelf. I’d send one to anyone needing one for cost of postage.

But I didn’t mean to heat the steel bolt - heat the aluminum pully - very carefully. Of course, as everyone knows, the main reason for heating in this restoration task is to expand the metal. still quench tho’.

I have had much better luck heating both the bolt/screw and the surrounding area and let it cool slowly. The heat breaks down the rust/corrosion into a powder. The trick is DON"T just try to unscrew it all at once, work the bolt/screw back and forth, maybe by tapping the tool a bit with a small hammer, while applying lots of penetrating oil. If you try to unscrew it all at once, the powder usually just locks it back up. Take your time, let the penetrant do it's thing. If this doesn't work the first time, do it again. Did I say take your time? In the case of the fan screws, an impact driver(one that you hit with a hammer) could very well help a lot. Take your time, did I say that? JMHO Dave

By the way, stay away from those spiral (un)easy outs. All they are good for is removing bolts that have been broken off from side pressure, not ones that have twisted off. All they do is lock the bolt in tighter as you try to remove it, or twist off making it pretty much impossible to drill it out. The square type easy outs are much better. Again, JMHO after fooling with this sort of thing for 40+ years. Dave