Screws Stuck in Water Pump

[openseas]

Hi all,
I wanted to change the water pump impeller of a Yanmar 15hp engine by myself, so I took out the water pump from the engine, which was easy ( two screws), then when I tried to take out the metal plate that covers the impeller, I was able to remove two screws, and four I couldn't, I almost ruined the thread as you can see from a close up picture. I cut the thread and deepen it, hopping that the screw driver would be able to loosen it, but I couldn't.
Also I tried to add WD-40, and still didn't work.
I know that when I take off of shore, I have to do everything by myself, and I am trying to learn anything I can about my boat.
Any suggestions, or tricks to loosen the screws?
Thanks,

Andy

[Cheechako]

Normal procedure: remove all the paint out from around the screw heads first. It may be too late for this as you have buggered up the screw heads already. Then give a sharp rap with a hammer and close fitting screwdriver to "shock" the threads.
At this point I would get the closest fitting screwdriver I could find. You can use a hacksaw blade or small square edge file to rework those slots so they have a clean slot. Use a lot of down pressure and try to get them started.
Failing that, you can grind or saw the heads off and try to turn the shafts after the cover is off.
I'd say try to drill them out, but I've found with slot head screws it's nearly impossible to stay on center... and you might scrap the pump trying.

[model 10]

You are in a bit of a pickle. It looks like the next step is going to be an easy out. Don't buy the first easy-out set you find. Some work really well and and others don't. The long skinny ones require a deep hole and the deeper the hole you need the harder it is to drill a nice hole. Short stubby types of easy-outs are better for short screws.
Go slow.

[donradcliffe]

My solution would be to use a dremel tool with a cutting wheel to cut flats on the screw heads, then use a small (genuine) vice grip to clamp on the flats and turn the screw. Many times the head will just break off, or sometimes you will have to cut it off with the dremel--then you use the vice grips on the stub after you have the plate off.

All of this is after you have sprayed with your favorite penetrating oil (liquid wrench, PB Blaster) and tapped the screw with a hammer and screwdriver and waited 6 hours, repeated at least twice.

[ryon]

Anti-seize, and hex bolts. Now that you know.

[sparrowhawk1]

Originally Posted by donradcliffe

My solution would be to use a dremel tool with a cutting wheel to cut flats on the screw heads, then use a small (genuine) vice grip to clamp on the flats and turn the screw. Many times the head will just break off, or sometimes you will have to cut it off with the dremel--then you use the vice grips on the stub after you have the plate off.

All of this is after you have sprayed with your favorite penetrating oil (liquid wrench, PB Blaster) and tapped the screw with a hammer and screwdriver and waited 6 hours, repeated at least twice.

+1. If you don't have a dremel tool a file will work. Take your time. I forget where I read it but transmission fluid and acetone mixed works as well or better than the store bought products. Try not to use too much force and rock it back and forth. If after a couple days they're still stuck you can try using a torch. If the heads break off the bolts use a punch.drill them out using a very small drill bit and slowly go up sizes until you have almost all of the bolt out, letting the bolt get hot and then spraying with penetrating oil. next would be to use an easy out, but if you don't have one a flat head screwdriver that fits inside Will often work

[skipmac]

Originally Posted by donradcliffe

All of this is after you have sprayed with your favorite penetrating oil (liquid wrench, PB Blaster) and tapped the screw with a hammer and screwdriver and waited 6 hours, repeated at least twice.

Since the screws are already a bit buggered you're going to have to work a little harder and more carefully to avoid trashing the whole pump.

Use PB Blaster. It works about 1000 times better than WD40 for loosening screws.

Clean the screw heads, spray well with PB Blaster, let it sit for a day. Get a hand held butane torch and heat the screws. Not too much, just to the point where it is slightly to hot to hold your finger on it. Add more PB Blaster. Tap all the screw heads several times with a hammer. Don't smack'em hard, but a firm tap. Then try to grab the screw heads with a good vise grip and turn.

BE VERY CAREFUL USING AN EZOUT. I have sworn off after 10-12 times breaking an EZOUT bit off in a screw (guess I'm a slow learner). EZOUTS are really hard metal so they can grip the hole but also very, very brittle and will snap off in a second. Once that happens you are really screwed. The only thing I've found to fix that is to grind the broken part out with an expensive diamond or tungsten carbide bit.

[openseas]

Hi,
Where do I find the (PB Blaster). I never heard of it before.

[skipmac]

Originally Posted by openseas

Hi,
Where do I find the (PB Blaster). I never heard of it before.

What country are you in?

[skipmac]

Originally Posted by openseas

Hi,
Where do I find the (PB Blaster). I never heard of it before.

OK, looked at your old posts and you mention going to a West Marine so you must be in the USA. In that case, Home Depot, most hardware stores (Ace?), Autozone, probably even West Marine.

[Stumble]

It was mentioned above, but needs to be pointed out again. Get rid of every slotted head screw on the boat. I can't stand the damn things. I prefer square or hex, but even a Phillips is worlds better than a slotted.

[Cheechako]

"BE VERY CAREFUL USING AN EZOUT. I have sworn off after 10-12 times breaking an EZOUT bit off in a screw (guess I'm a slow learner). EZOUTS are really hard metal so they can grip the hole but also very, very brittle and will snap off in a second. Once that happens you are really screwed. The only thing I've found to fix that is to grind the broken part out with an expensive diamond or tungsten carbide bit. "
Yes, ditto on that for sure. This would be a tiny Easy Out. Not to mention trying to drill a centered hole in what... #8 screw? I like to put in SS Allen head bolts. Easy to use when turning in the blind! And SS and bronze are very forgiving together.

[sparrowhawk1]

+1 on ez breaks and using Allen heads

[JPA Cate]

....And if you want a quick changing water pump impeller cover, Google on Speed Seal, it's what we're using now. Order extra o-rings for it at the time of purchase; otherwise they're expensive with the shipping.

Ann

[skipmac]

Originally Posted by Stumble

It was mentioned above, but needs to be pointed out again. Get rid of every slotted head screw on the boat. I can't stand the damn things. I prefer square or hex, but even a Phillips is worlds better than a slotted.

Amen to that. How do I hate slotted screws? Let me count the ways.