2001 Duramax 2500HD Diesel (LB7).

Last week I got a Coolant Low light. Checked my level in the reservoir and yep it was low. So bought some Dex-Cool and refilled it. Also noticed a small puddle under truck (about quarter sized) that day. The next few days I have noticed the puddle getting bigger and bigger by the next morning. It is now about 12-18 inches across in the morning. I'm thinking water pump.

I have the Chevy Maintenance manuals. I've checked the manuals and TheBac's information http://www.dieselplace.com/forum/showthread.php?t=214076 (thanks TheBac) and I have this question.

Do you need to buy the J44643 Fly Wheel Holding Tool? If not, could someone explain how to hold the flywheel still so as to remove it? The reason I ask is the manuals say to "Raise the vehicle, remove the starter, insert the J44643, then lower the vehicle". Why do you need to raise the vehicle with the tool? Is it because the starter is engaged against the teeth in the engine and you would not be able to disengage it with that pressure?

What are procedures without the tool? Can't you just leave the truck on the ground and let the weight of the truck be the counter to the bolt turning on the crank balancer?

Thanks in advance.

I dont know why they are telling you to lift the truck mayby to make getting under it more easy it has nothing to do with the removel of the starter itself there are several ways to remove the balencer bolt. I removed the starter and put the end of breaker bar into one of the holes in the flywheel and then lossened the bolt. you either need someone to hold the bar so it stays level when you crank the bolt loose or tie it off if you dont have a extra set of hands. that is what I did. good luck

I dont know why they are telling you to lift the truck mayby to make getting under it more easy it has nothing to do with the removel of the starter itself there are several ways to remove the balencer bolt. I removed the starter and put the end of breaker bar into one of the holes in the flywheel and then lossened the bolt. you either need someone to hold the bar so it stays level when you crank the bolt loose or tie it off if you dont have a extra set of hands. that is what I did. good luck
that works well but stresses the flexplate because it rides or stresses 1 point, the adapter evens the stress, If you break the teeth from the flexplate or the plate its self then you gatta pull the allison, to me it was better to be safe than sorry

I took the truck to a local mechanic and they found a leak in the water pump outlet pipe. They said they could not fix it because they didn't have a procedure in their online manuals to replace it. Also, they said they couldn't get the part unless they ordered it from the dealer.

My question is, Is this difficult to change. The Chevy manuals say that you must remove the water pump to change out the outlet pipe. If that is true, then I think I'll have the next mechanic change out the water pump with the pipe since he's already removing the pump anyway? My truck has 122,000 miles. Would you replace the pump and the pipe?

Yep, I would replace both while you're in there if you have the funds to do so.

Did they say where the pipe was leaking at? Front connection, back connection, or a hole? If its not a hole I wouldn't replace the tube. Chances are either the gasket on the back of the tube or the O-ring on the front (in the back of the water pump) is cracked. I also agree, with the miles that you have on your truck, if you already have the water pump off you might as well replace it now.

We used a 1/2" breaker bar in through the access hole in the bottom of the transmission. Then with a wrench on the flywheel bolt, we hit the end with a 5 lb hammer until it broke loose. Didn't jack it up.

ok so mine started leaking last week and I replaced it today. Took about hours but I also replaced lower hose and upper hose and fuel filter. Here is the the play by play. Disconect battery, remove upper fan shroud & pcm on driver side of shroud I removed from the truck and set aside, Then I removed the fan by putting air hammer and tapping nut free (it is normal thread right handed). Then I installed the fly wheel hold tool I got from lisle part number 22100 also comes with the 12 point 36mm socket. removed the balancer bolt with a 1/2 snapon breaker bar with a 1/2-3/4 adapter. Now I jacked up the front end and removed the tires and lowered to the ground, then removed the driver and pass fender liners (pass because i was due for a fuel filter too) you only have to remove the driver side for the water pump. remove the idler pulley, then I vacumed out the coolant if you don't have a vac pump the drain before lowering to the ground. Then remove the lower hose to pump and the bypass hose clamps. Then remove the intercooler tube on the driver side to get to the 2 nut's on the back of the water pump pipe. Then remove pipe bolts on top of the pump then the other 2 bolts holding it on the engine, remove pump houseing and then unbolt pump form it, basicly reverse to install,

Thats great, thanks!

2001 Duramax 2500HD Diesel (LB7).

Last week I got a Coolant Low light. Checked my level in the reservoir and yep it was low. So bought some Dex-Cool and refilled it. Also noticed a small puddle under truck (about quarter sized) that day. The next few days I have noticed the puddle getting bigger and bigger by the next morning. It is now about 12-18 inches across in the morning. I'm thinking water pump.

I have the Chevy Maintenance manuals. I've checked the manuals and TheBac's information http://www.dieselplace.com/forum/showthread.php?t=214076 (thanks TheBac) and I have this question.

Do you need to buy the J44643 Fly Wheel Holding Tool? If not, could someone explain how to hold the flywheel still so as to remove it? The reason I ask is the manuals say to "Raise the vehicle, remove the starter, insert the J44643, then lower the vehicle". Why do you need to raise the vehicle with the tool? Is it because the starter is engaged against the teeth in the engine and you would not be able to disengage it with that pressure?

What are procedures without the tool? Can't you just leave the truck on the ground and let the weight of the truck be the counter to the bolt turning on the crank balancer?

Thanks in advance.

Best thing to do is buy the Lisle tool. At the time I did my pump, the Jtool or extension in the flywheel were the only ways to go. I really need to update that DIY one of these days.

I replaced my water pump at 126,000 mi. on my 03'. It took me Three hours and twenty minutes with no problems and the engine running again. I'm not a professional mechanic and found it easy to do with no manual; it's just a lot of work!
New Bosh pump with Lifetime Warranty was $65.00 at Pep Boys.
3/4" breaker bar at Harbor Freight Tools was $20.00
3/4" Torque wrench at Harbor Freight Tools was $80.00
12” of 3/8” fuel injection hose " for the bypass tube behind the fan idler" at Pep Boys ($1.69) “only need about 3” but Pep Boys only sells 12” at a time, also the dealer wanted $25.00 for this 3” X 3/8” hose. Even the parts guy thought it was NUTS!”
Dielectric grease ($5.99) at Pep Boys. "to lube up the o-rings during assembly" (do not lube the upper thermostat o-ring, you have to apply the grease only to the bottom cast aluminum inlet opening of the thermostat housing, or the o-ring will roll and or get pinched during re-insertion of the thermostat bypass tube"
Lisle 22100 Flywheel Locking Tool for 6.6L Duramax was $33.10 at Amazon "with this simple tool I saved a lot of time by not having to remove and replace the starter, it just slips in the inspection hole on the Allison, and the kit also included the 36 mm 12 point socket to remove the balancer bolt".
The new water pump came with most of the gaskets, except the upper thermostat bypass tube tube o-ring. It came with a paper flange gasket for the oil cooling tube connection but I had to go to the dealer for the upper thermostat o-ring ($2.00), so I also purchased the OEM metal flange gasket ($2.47) and threw away the paper gasket the came with the new pump.
I'd do it again!....wasn't bad at all!....Good luck!

Ken
Electrical Contractor