*&$%@#### Water pump !!! Help?

[joe bleaux]

Hi, again, members.

In between curse-fests and issuing oaths at the design engineers at Chevrolet, I am trying to remove the water pump for replacement on my '98, C2500, 6.5TD.

I have searched and not found anything that tells me that I do or do not have to remove the dual-thermostat cross-over. Do I?

Who ever heard of having to remove the timing-chain cover in order to remove the water pump?

There are three blind studs that are behind the timing-chain housing that need to be removed or, the nut thereof, in order to remove this pump.

What a ghastly job! Am I going to have to remove the upper intake manifold, as well?


Thank you, as usual.

Joe

[DA BIG ONE]

These pumps do last a long time, time, labor and more *&(#_)(& until its done and not as bad as one would think.

If I remember correctly (I did mine when replacing IP) the oil fill tube, lower rad hose, pump to stat housing hose, the fan & clutch, shroud, lower crank pulley and balancer (check these closely for wear and damage), timing cover then remove the pump bolts from the backside of timing cover.

Suggest you do that timing chain, or put in gear drive while its apart.

[Iain]

When I did mine, I upgraded to the high flow waterpump and dual thermostats. I did not have to take of the intake manifold though. If you are changing the water pump, should change your thermostats as well but you should not have to remove the entire housing to do this operation.

Iain

[Robyn]

The water pump comes off easily without removing the crossover.
The waterpump has the plate bolted to it from the back side but the whole unit comes off the front cover easily.

Get the fan shroud and that stuff out of the way and then the belt, pulley and fan clutch/fan come off and you have plenty of room to access the pump.
There are large and small bolts all the way around the unit and then it comes right off.

Remember to use a gasket when replacing the pump to the cover as GM used a shelac there instead of a gasket. The metal plate on the back of the pump needs a gasket between it and the pump.
Inspect the plate for cavitation erosion and if any very deep rusty spots are found, replace the plate as these can rust though and dump coolant into the oil.

****** BE SURE and use a blue loctite product on the bolts that hold the plate to the pump. If they come out it can be GAME OVER as they fall into the timing gear train.

This is an easy 1-2 hour job with time for coffee and a donut too. :D

Done these many times on 6.2/6.5 units

Robyn

[joe bleaux]

Robyn,

If you can replace a water pump on this truck in 1 to 2 hours, with time for coffee and donuts, you must be an absolute miracle worker! I'm not doubting you, I am just amazed.

I have everything mentioned, removed and all of the w.p. bolts removed except the three blind studs that have the nuts on the backside of the timing chain housing.

Doesn't this truck ('98, 6.5td, have the dual thermostats? And, didn't I read in this thread, that this thermostat housing did not need to come off? I will read again.

Thanks for the reminder about the blue Locktite. I have red and green but will get the blue. I will gove over the plate very carefully and replace if even a dimple of erosion is there.

I am curious - how long did it take you to do your FIRST water pump on these trucks? There is an invitation to brag.:)

Thanks for the input.

Joe




The water pump comes off easily without removing the crossover.
The waterpump has the plate bolted to it from the back side but the whole unit comes off the front cover easily.

Get the fan shroud and that stuff out of the way and then the belt, pulley and fan clutch/fan come off and you have plenty of room to access the pump.
There are large and small bolts all the way around the unit and then it comes right off.

Remember to use a gasket when replacing the pump to the cover as GM used a shelac there instead of a gasket. The metal plate on the back of the pump needs a gasket between it and the pump.
Inspect the plate for cavitation erosion and if any very deep rusty spots are found, replace the plate as these can rust though and dump coolant into the oil.

****** BE SURE and use a blue loctite product on the bolts that hold the plate to the pump. If they come out it can be GAME OVER as they fall into the timing gear train.

This is an easy 1-2 hour job with time for coffee and a donut too. :D

Done these many times on 6.2/6.5 units

Robyn

[joe bleaux]

Iain,

I ***think***? this has the dual thermostats but do you mean that you don't have to remove the thermostat housing in order to replace the 'stats'?

Thanks

Joe



When I did mine, I upgraded to the high flow waterpump and dual thermostats. I did not have to take of the intake manifold though. If you are changing the water pump, should change your thermostats as well but you should not have to remove the entire housing to do this operation.

Iain

[Iain]

I do not believe so. When I did mine I converted from a single thermostat housing to a dual and to the high flow water pump. If I remeber right, you should not have to remove it when changing the water pump. But you should look at your thermostats and change them if they are old/gummed up/stuck/whatever. You can get the 4 bolts off of the cover with a bit of swearing. When I did mine, I put the thermostats and the cover on the housing and then put the housing on. It looked easier to me to do it that way as the bottom 2 bolts on the thermostat cover looked awkward to get at.

Iain

[joe bleaux]

Da Big One,

You guys that say this is not a bad job amaze me. I have changed a few water pumps in my time but TO ME, this is a beast.

I am replacing the water pump, harmonic balancer and serpentine drive pulley, timing chain and attendant gears, oil cooler lines with different fittings, thermostats, new coolant and whatever else I come across while doing this job.


Thanks for your comments.

Joe


These pumps do last a long time, time, labor and more *&(#_)(& until its done and not as bad as one would think.

If I remember correctly (I did mine when replacing IP) the oil fill tube, lower rad hose, pump to stat housing hose, the fan & clutch, shroud, lower crank pulley and balancer (check these closely for wear and damage), timing cover then remove the pump bolts from the backside of timing cover.

Suggest you do that timing chain, or put in gear drive while its apart.

[Robyn]

The first one of these was on an 82 6.2 which is the same format.

The only issue can be if you fail to find the small bolts on the under side of the pump. These can become covered with dirt and such and can cause issues if you fail to find them.

To answer your question (And I will not brag, not that I dont enjoy it) :D

I can't remember the job on the first one but I am the currious type and generally do well with this sort of thing.
I do remember using a small mirror on a stick to look around under the pump when the removal of the obvious bolts did not allow it to fall off.:D

As far as a two hour (2) it can be done easily if you have all the tools laid out and the new pump and such ready to go.

The coffee and donut are optional :D

Now if you have never done it and are not familiar with the tools needed it may take away time alocated for the donut. :rolleyes:


OH BTW the blind bolts are of no issue until you get the pump off.
Best

Robyn

[joe bleaux]

Heck, I don't even have a donut, much less every thing laid out.

I just wish that I had a book from Helms on this beast.

I now have the pump off but now, I am stumped on getting the timing chain housing off. I have lines up the dots at 6 o'clock on the camshaft timing gear and 12 o'clock on the mating gear. Now, it seems that I am going to have to remove camshaft timing gear to remove 3 bolts that I CAN see that may be holding the t.c. housing on.

Oh, I did remove the four bolts that go to the front of the oil pan.

Do you agree or have more/other data, Robyn?


I think we weren't on the same page on the blind bolts. I think that I NOW see three, perhaps four, bolts that you were talking about. I was referring to the bosses on the top of the pump.


Thank you.

Joe




The first one of these was on an 82 6.2 which is the same format.

The only issue can be if you fail to find the small bolts on the under side of the pump. These can become covered with dirt and such and can cause issues if you fail to find them.

To answer your question (And I will not brag, not that I dont enjoy it) :D

I can't remember the job on the first one but I am the currious type and generally do well with this sort of thing.
I do remember using a small mirror on a stick to look around under the pump when the removal of the obvious bolts did not allow it to fall off.:D

As far as a two hour (2) it can be done easily if you have all the tools laid out and the new pump and such ready to go.

The coffee and donut are optional :D

Now if you have never done it and are not familiar with the tools needed it may take away time alocated for the donut. :rolleyes:


OH BTW the blind bolts are of no issue until you get the pump off.
Best

Robyn

[Robyn]

The front flange on the pan has bolts in it, remove them. The ballancer and pulley have to come off the crank, (puller needed)
The remaining bolts in the cover must be removed and the the cover will come off. Be careful and dont get rough with it as these can be broken if you get to wild with a pry stick. The cover is piloted with Two (2) aligning dowels so its a no brainer.
The front of the pan is gooped with RTV to the cover. You will need to replace the cover seal if you do this also.

The front of the pan can be regooped with Black High temp RTV when you reassemble. Do not take the pan bolts loose on the side rails.
If you are doing this to tighten up slop in the cam drive a simple addition of a new chain will usually fix these fine. Be sure and use blue loctite on the bolts that hold the gear to the IP and also the front cam bolt.

Same rule applies, Bolt gets loose, game over!! :eek:

Good luck.
Need anything more just ask

Robyn

[DaveNY]

What Kind Of Donut???

[joe bleaux]

Let me ask this in a different way as perhaps my question got lost in my verbosity.

In order to get the front cover otherwise known as the timing chain housing off, do I first remove the camshaft gear to remove what looks three or more bolts holding said housing onto the front of the engine?

Thank you.

And Dave, glazed, if you don't mind and I will take a f.f. at it.

Joe

[diesel65]

To pull the timing cover you need to remove the three bolts that hold the gear to the injection pump then remove gear. The three bolts that you see behind the gear are studs to hold the injection pump. Those studs do not come out, you need to remove the three nuts that hold the injection pump. Mark pump to cover for reinstallation.
Make sure you watch your timing marks upon installing replacement parts and use red locktite for the bolt that holds the two gears to the cam shaft.
To avoid headache later, consider replacing the crank sensor at this time.