question GMC CCKW Water Pump Questions

[Vulture]

Guys

 

I seem to have a lot of play in the water pump bearing. There is quite a ‘wobble/rock’ in the hub that the fan blades attach to. No fluid loss as yet.

 

I’m contemplating getting ahead of the problem here and replacing it.

 

I have two questions for your kind consideration:

 

1. Should I try and get it repaired, or would I be better of getting a part ex recon one from Rex Ward for £ 102 ?

 

2. The instructions (below) look straightforward, is there anything in particular to watch for ?

 

Kind regards to all

 

Vulture

 

 

 

 

 

 

 

b. Removal.

 

(1) DRAIN SYSTEM AND REMOVE FAN AND DRIVE BELT.

Remove radiator cap; then open radiator and cylinder block drain cocks and allow cooling system to drain.

Remove four fan to water pump cap screws and remove fan blades.

Remove drive belt (par.108).

 

(2) REMOVE PUMP CONNECTIONS.

Loosen radiator outlet pipe to water pump hose clamp screw at water pump and remove hose from water pump.

Loosen water by-pass elbow hose clamp screws, and loosen hose [(GM-2137582) G501-02-17816] from elbow.

 

(3) REMOVE PUMP.

Remove four water pump to cylinder block cap screws (fig. 102).

Remove pump [(GM-2103002) G85-11-01740] and gasket [(GM-838137) G85-11-00960] from vehicle.

 

(4) REMOVE BY-PASS ELBOW.

Unscrew water by-pass elbow from water pump for installation in replacement pump.

 

c. Installation.

 

(1) INSTALL BY-PASS ELBOW.

Screw water by-pass elbow tightly into water pump.

Coat threads of elbow with anti-seize compound, mica base.

 

(2) INSTALL PUMP ON ENGINE.

Place a new water pump to cylinder block gasket in position, then place water pump in position on engine, directing inlet elbow into hose. Install one 17/s-inch cap screw with lock washer in water pump bolt hole just above water inlet and tighten finger-tight.

Then install remaining three cap screws with lock washers (fig. 102), assembling fuel and oil lines clip and generator adjusting arm.

Tighten all four cap screws evenly and firmly.

 

(3) INSTALL PUMP CONNECTIONS.

Tighten water by-pass elbow hose clamp screws.

Install radiator outlet pipe to water pump inlet and tighten hose clamp screws.

 

(4) INSTALL FAN AND DRIVE BELT AND FILL SYSTEM.

Install and adjust belt (par. 108).

Position fan blades on water pump hub with straight edge of blades toward radiator-curved edges toward engine. This will position fan so notches in blades will provide clearance with crankshaft balancer.

Install four cap screws (fan to water pump) with lock washers and tighten firmly.

Close radiator and cylinder block drain cocks, then fill system (par. 17).

Edited September 19, 2012 by Vulture
Grammar

[N.O.S.]

On the basis you are not contemplating stripping it down yourself and sourcing the parts (repair kits are available at around £45 plus freight from Holland - say total £65, then as a water pump repair novice you might spend around 3 hours messing about rebuilding it - say an extra £45 worth of your precious time), then in answer to Q1) - if I had a choice between:

 

a) finding a water pump repairer I'd be prepared to trust with an old pump (I'm sure they're out there somewhere, but have heard stories of troublesome repairs), sweating on them being able to source the correct parts, and paying the uncertain cost, and

 

b) :cellphone:discussing the latest GMC news (only one hour of your precious time!) and paying a fair price,

 

- you know what? I think I'd go for 'b' :cheesy:

Edited September 20, 2012 by N.O.S.

[JOURNEYMAN]

Hi vulture,

i have recently had to change the water pump on my gmc. Save yourself a lot of problems and get a re-built unit from rex ward. Save a lot of hassle by taking the radiator out to give yourself decent access , there is

little or no space to remove the fan without the chance of damaging the radiator core. Take the fan off before removing the water pump and carefully lever the pump casing off if it is stuck to the block , to avoid damaging the casing. The new pump comes with a gasket to go between the pump casing and the block. Make sure any old gasket is cleaned off. Put the fan , drivebelt back and re-tension the belt before putting the radiator back. You can do the job with the radiator in but you risk damaging the radiator ,also it can be difficult to line up the bolts/holes in the fan/pulley as i found out the first time. While you are at it ,flush the engine out to clear out any muck in it ,do the same with the radiator. When putting the radiator back in,

be careful not to damage the core, i covered mine with a sheet of cardboard to protect the core. Have a good look at any wiring , pipework etc... On the front cross-member while the radiator is out ,also a good time to re-paint that area as well.

Hope this helps,sorry if it is too late but i have only just read the post.

Best wishes,

steve.

[N.O.S.]

... You can do the job with the radiator in but you risk damaging the radiator ...

 

.....and your knuckles! :argh:

[Vulture]

Hi vulture,

i have recently had to change the water pump on my gmc. Save yourself a lot of problems and get a re-built unit from rex ward. Save a lot of hassle by taking the radiator out to give yourself decent access , there is

little or no space to remove the fan without the chance of damaging the radiator core. Take the fan off before removing the water pump and carefully lever the pump casing off if it is stuck to the block , to avoid damaging the casing. The new pump comes with a gasket to go between the pump casing and the block. Make sure any old gasket is cleaned off. Put the fan , drivebelt back and re-tension the belt before putting the radiator back. You can do the job with the radiator in but you risk damaging the radiator ,also it can be difficult to line up the bolts/holes in the fan/pulley as i found out the first time. While you are at it ,flush the engine out to clear out any muck in it ,do the same with the radiator. When putting the radiator back in,

be careful not to damage the core, i covered mine with a sheet of cardboard to protect the core. Have a good look at any wiring , pipework etc... On the front cross-member while the radiator is out ,also a good time to re-paint that area as well.

Hope this helps,sorry if it is too late but i have only just read the post.

Best wishes,

steve.

 

Hi Steve

As it happens I was just this afternoon speaking with Rex Ward, and I have arranged to swing by his place on Thursday with the old one, and pick up a replacement from him, along with a new piece of hosing that goes down to the bottom of the rad.

With this deadline in mind I grabbed a few minutes after I walked my dog at tea-time tonight, and took a short (slightly shaky) video of the play in the fan.

 

[video=youtube_share;v-6mUOgceMA]

 

I then after getting the belt slackened right off proceeded to removed the 4 bolts holding the fan in place. As recommended I had some cardboard in place protecting the radiator. As you say, access to the bolts sucks, however I have small hands and so was able to get them off with only, for me, a small amount of swearing :argh::rofl:

I'm busy now for the weekend, but hope, weather permitting, to finish the removal job on Monday. I hear what say about taking the rad out, I shall give it some thought as they say

 

Kind regards

 

Vulture

[Vulture]

On the basis you are not contemplating stripping it down yourself and sourcing the parts (repair kits are available at around £45 plus freight from Holland - say total £65, then as a water pump repair novice you might spend around 3 hours messing about rebuilding it - say an extra £45 worth of your precious time), then in answer to Q1) - if I had a choice between:

 

a) finding a water pump repairer I'd be prepared to trust with an old pump (I'm sure they're out there somewhere, but have heard stories of troublesome repairs), sweating on them being able to source the correct parts, and paying the uncertain cost, and

 

b) :cellphone:discussing the latest GMC news (only one hour of your precious time!) and paying a fair price,

 

- you know what? I think I'd go for 'b' :cheesy:

 

 

NOS

 

Option 'b' it is :cool2: :-D

[Vulture]

Chaps

 

Picked up a replacement pump from Rex. Now need to do the change.

 

The fan is off, and I have some questions...

 

Ignoring the colour, does yours look like this ?

 

 

Nothing about this fan looks balanced in its design :shocked::nut::undecided:

 

:help: What technique have you used to get this bolt out ?

 

 

Access is horrible. There isn't room to get a socket on, and currently I don't have a spanner that will fit in there. Its got a slot, but unless I take the rad out I can't get a screw-driver in (which I don't want to). Even then I'm not confident I could get enough leverage on it.

 

My current thinking is to get a piece of tempered steel in it and lever it round. I'm open to any other ideas...

 

Kind regards to all

 

Ian

Edited October 5, 2012 by Vulture

[N.O.S.]

Unless my memory is playing tricks, with the fan blade bolts out you should be able to give the pulley and hub a sharp tap and remove it? More room will result.

 

I'd forget the slot, use the hex somehow (ring spanner with good offset or socket with pulley off).

 

Oh the joys of doing a job the first time - or so long after you did it before that you've forgotten how to do it :rofl:

[N.O.S.]

The fan is balanced, and designed to give just one gap 2 gaps :blush: between blades large enough to get a greasy hand through :laugh:

Edited October 8, 2012 by N.O.S.

[Vulture]

The fan is balanced, and designed to give just one gap between blades large enough to get a greasy hand through :laugh:

 

I'm sure it is, it just doesn't look like it ! :nut:

[Gordon_M]

The fan is balanced, and designed to give just one gap between blades large enough to get a greasy hand through :laugh:

 

I've never thought about that before but you are absolutely right.

 

There are water pump variations, particularly length, but I'm sure Rex would give you the correct one automatically. From hazy memory the truck one was shorter than the DUKW one, but you could use the truck one on the DUKW with a spacer adapter - no idea how you got access though.

 

While you have the pump off back flush the radiator and the block.

[Vulture]

Unless my memory is playing tricks, with the fan blade bolts out you should be able to give the pulley and hub a sharp tap and remove it? More room will result.

 

I'd forget the slot, use the hex somehow (ring spanner with good offset or socket with pulley off).

 

Oh the joys of doing a job the first time - or so long after you did it before that you've forgotten how to do it :rofl:

 

NOS

 

Spoke to Rex. You need a special four fixture puller tool to get the pulley off, which can be only done with the pump off. He suggests I either:

1. Grind down a spanner to fit.

2. Use a Side Action Screwdriver.

3. Use something else (tempered obviously) that will fit in the slot.

 

I shall have a root around in my tool boxes this afternoon and think about how to proceed. I'd never heard of a Side Action Screwdriver before, and after a quick search on the net, it would seem to fall into the category of 'as rare as rocking horse sh1t" LOL

[Vulture]

I've never thought about that before but you are absolutely right.

 

There are water pump variations, particularly length, but I'm sure Rex would give you the correct one automatically. From hazy memory the truck one was shorter than the DUKW one, but you could use the truck one on the DUKW with a spacer adapter - no idea how you got access though.

 

While you have the pump off back flush the radiator and the block.

 

Hi Gordon

 

Yes' I'm going to give it a good flush out.

[Vulture]

Got the pump changed yesterday Straightforward apart from getting the top left bolt in. That was real pig which had me struggling for an hour and a half :mad:.

[JOURNEYMAN]

Well done mate , think how easy the next one will be !!!!

[Vulture]

Well done mate , think how easy the next one will be !!!!

 

Indeed !

 

Here's a photo. If you look closely you can see the damage being done to the impeller

 

[snort]

Indeed !

 

Here's a photo. If you look closely you can see the damage being done to the impeller

 

[ATTACH=CONFIG]68294[/ATTACH]

 

 

Yes it looks like it was due for a change, still worth keeping the old one it could be refurbished and kept as a spare.

[Vulture]

Yes it looks like it was due for a change, still worth keeping the old one it could be refurbished and kept as a spare.

 

I'm dropping the old one off with Rex Ward this week. One of his conditions of sale is that the old one must be part-exd.

 

[N.O.S.]

Unless my memory is playing tricks, with the fan blade bolts out you should be able to give the pulley and hub a sharp tap and remove it? More room will result.....

 

Well this morning I finally remembered that I've done a John Deere since the GMC, and it was that pulley which will come off :n00b:

[Degsy]

Well this morning I finally remembered that I've done a John Deere since the GMC, and it was that pulley which will come off :n00b:

 

Senility creeping up??????

[Vulture]

I've decided that each time I do some work on the truck I'm going to write up a Work Instruction on the actvity, so (a) that if I have to do it again, it will be more straightforward, and (b) it might help other people out. Using this as my first effort, I've taken the instuctions from the TM, broken them down further, and then added a bunch of notes (whilst the activity is really fresh in my mind). Later in the week I'll add some photos. Would anyone like to help me out and do a proof read ?My subsequent plan is make it available to download. (Not quite sure where from yet) Cheers Vulture