Another 98 Waterpump

Spent the better part of today trying to get that darn fan off or my 98 5.7. I even went and bought a $90:shakehead tool that hooks to the pulley bolts and it broke:( :( :( . Thank god they took it back. Tried with pump on the truck and off the truck and this thing will not budge. So here is where I am at: has anyone ever had to cut one of these things off?? I am that desperate!!

If you're talking about the 4 bolts that hold the fan clutch and pulley on the front of the water pump (I know you can't get a pneumatic impact wrench on them), have you tried a backyard impact wrench? (I almost called it a hillbilly impact wrench but don't want to offend anyone. :nono: )

Translation: Hold a box-end wrench on the bolts and whack it with a bit ole' hammer, with the water pump on the engine and the fan belt in place to hold the pulley.

I've had good luck with this method by making sure the impact direction of the hammer is towards the center of the pulley instead of to the side, as that lessens the tendency to want to turn the pulley as you hit it. If that don't get it loose, get a bigger hammer!

Anyway, have plenty of bandaids - that one's a knuckle-buster! Good luck.

I changed one on my sons GMC I used a OTC tool over the 4 bolts and another one to unthread the fan. My tool uses a 1/2inch breaker bar to hold the tool and I used a 36mm open end wrench to unscrew the fan. Use P-B blaster
to soak the fan threads. I didn't have any problem getting it off. It unthreads like loosening a bolt. Look at the rebuilt water pump where the threads are and soak it good.
You could use a 3 foot and 4 foot pipe wrench.
Note any left hand threads will be stamped with a L but I'm positive on my sons GMC every thing was right hand threads but it was tight.
When holding the 4 bolts steady use a mallet and smack the wrench on the fan. Be careful and don't hit your fingers.

On the 98 there are 4 bolts that hold the pulley to the pump and four bolts that hold the fan to the clutch. In between the clutch is held onto the water pump via a big right hand thread nut. this is where my trouble is.

I understand that and is what I thought I was telling how to get off. I used a double sided wrench which fit a few vehicles. To hold the 4 nuts and a 36mm wrench to unthread the fan. I have a big mallet with plastic ends I smacked the 36mm wrench with.

Sorry. I misunderstood. Tomorrow is another day I'll try to fab something.

Ah, yes. I remember that devil. As suggested by rhandwor, I used a small pipe wrench and a big breaker bar (old motorcycle fork tube) along with a hammer to get that loose on my '98 blazer, but I think it's the same as you have on your '98 pickup.

My '93 C3500 does NOT have a threaded fan clutch, so I forgot about that little twist.

I think the common point here is to get a "BIG HAMMER".

Sorry. I misunderstood. Tomorrow is another day I'll try to fab something.


15 in cresent and a BFH. Comes lose every time.

Well, I spent an hour or so this morning making a "wrench" that bolts to the 4 bolts on the pulley then beating my new Craftsman adjustable wrench silly. Even tried heating it up. Nothing. So, out came the saws all and air chisel and off it came. Thanks for all of your suggestions.

You heated it up cherry red and it wouldn't break loose really surprises me.
I guess you will make a trip to the junk yard and buy another piece or maybe go totally new.

I'll have to say it was not "cherry" red. I was afraid of warping the pulley and wrecking the seal in the clutch. I bought a new one.

this might sound getto but since the pump you are taking off is bad. Leave the fan on remove the pump, then remove the back plate and stick a screwdriver up in the pump... Like I said getto but who cares the pump is junk anyway...

I have found on other equipment if you hold a sledge hammer to one side and smack the other side going all the way around it helps loosen things up.
Also the wrench holding the 4 bolts has to be set against the ground or the frame. Otherwise when you hit the wrench with a hammer as you hold the wrench you aren't getting full effect.

The $90 tool that broke, I had fixed on a piece of angle iron against the battery. 1st try off the truck was to remove the back plate and jam it up with a screw driver. Thought I had it but was actually turning the flange on the front of the pump. Next was a piece of 3" x 1/8" flat steel cut and drilled to fit two pulley bolts, held the pump in my vise with the steel on top of work bench. Beat on my wrench and bent that steel into pretzel. Next was a piece of 2" angle iron jigged up the same way and this time I had a 1 foot extension on my wrench. The first wap and that extension backfired across my garage. Tried one more try with the heat then broke out the saw.

I was more concerned with other people reading the posts as your job was finished. You just ran on a job that was cold welded I think is the proper term. The grain structure grows together. I've had to burn or grind off a few nuts myself.

The $90 tool that broke, I had fixed on a piece of angle iron against the battery. 1st try off the truck was to remove the back plate and jam it up with a screw driver. Thought I had it but was actually turning the flange on the front of the pump. Next was a piece of 3" x 1/8" flat steel cut and drilled to fit two pulley bolts, held the pump in my vise with the steel on top of work bench. Beat on my wrench and bent that steel into pretzel. Next was a piece of 2" angle iron jigged up the same way and this time I had a 1 foot extension on my wrench. The first wap and that extension backfired across my garage. Tried one more try with the heat then broke out the saw.

Wow... Don't you just love it when engineers take the time to change something that worked just fine before to make it "better"

You know, I have been rethinking this whole truck and all of the problems that I have had, and am having. From the tranny, the fuel pump, the fuel guage sending unit, the fan clutch, the intake gaskets, the engine knock, broken outside door handle, cracked radiator tank, ball joints, the list goes on. I have had a '55 Chevy, '63 and '66 Fords (all pickups) with never a problem. Before this '98 Chevy I had a 1980 Datsun pickup with over 300,000 miles on it that I replaced one clutch and thats was it. California Smog Laws now allow 1977 vehicles to be exempt, so guess what I am looking at.

"From the tranny, the fuel pump, the fuel guage sending unit, the fan clutch, the intake gaskets, the engine knock, broken outside door handle, cracked radiator tank, ball joints, the list goes on."

for a second there I thought you were listing all the things I have replace on my truck...

What a cowinkidink.

The pistons in the new pickups have mini skirts to save money.

I thought that the 5.7's had the longer pistons and the newer 5.3's had the short ones.

I was refering to the 5.3L which most newer trucks have.