Water Pump

[PK]

I need to rebuild or replace the water pump on my M38. I have heard it is difficult to remove the pulley in tact. I am therefore leaning toward replacement.

Has anyone used the water pumps from Krage Motor Sports (these come with the pulley already on)?

If I go with the rebuild option or replacement without a pulley, is there a trick to remove and replace the pulley on to the water pump without breaking it?

I would also appreciate any advice or tips when removing and replacing the water pump.

Should I use gasket seal or just the new gasket?

What type of gasket seal?

Thanks
PK

[wesk]

The water pump rebuild as described in the engine TM is one of the more simple repairs you can do yourself. The two pullers shown in the manual are usually available at any automotive parts store and at most online tool dealers. The two-bolt pullers are a necessity in any toolbox. The special bell shaped puller for the impeller is a little more pricey and won't get used very much but it can usually be found at the tool rental places. A hydraulic press is nice to have for many different tasks. A less expensive arbor type bench mount press will work as well.

The impeller removal is the toughest task. Proper positioning of the impeller and the pulley for belt alignment is important. The problem when opting for an exchange overhauled pump is you must still deal with the pulley. If you deal incorrectly with it you can damage the impeller.

The cleaning up of the inner forward face of the pump can be done several ways without the special Willys tool.

Or you can remove your pump and take it to your local automotive machine shop and have them overhaul it and give you back the same pump with the correct pulley.

90% of gaskets are designed to do their job without any sticky help. If you feel compelled to use something then Permatex #1 is what you should use and apply it to one side only of the gasket. Preferably the side against the pump so when you have to remove it the gasket stays with the pump and it's easier to remove the old gasket on the bench then it would be trying to hang over the grill and do it.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[cknight]

A word of caution. I replaced my pump when I had the engine rebuilt. I took the pump to a local shop to have the pulley removed and than pressed onto the new pump. The dingbat that removed the pulley tried to pull the pulley with the wrong type puller and bent the pulley a little. I was able to get it back almost perfect but it does have a slight wobble in it now. These pulleys are not easy to find, so use the correct puller or give the manual to person doing the job and make sure they use the correct tools.

Good luck

[OKCM38CDN]

I rebuilt my water pump and knowing I was not going to reuse the impeller I dridded a hole next to the shaft and split it to get it off. Then I used a brass hammer and plenty of lube and drove the new impeller on till flush with the shaft... been running good for 2 years without problems...

As for the pulley I left it on... I just needed to change the fiberwasher...

Hope this helps...

[G740]

Further to the discussion of pulley removal. You have better check the bore diameter and the new shaft diameter before re-installing the pulley. You can only do this once, maybe twice before the press fit is not what it should be. The result will be a fan and pulley lauching thru your radiator.
Second. The pumps with the cast pulleys on them are junk. The pulley is not manufactured correctly, and your belts will not run in a straight line. Lots of dealers out there willing to take your money and sell you junk. Some of us don't. We may cost a little more, but you get what you pay for.
Regards,
John Bizal
Midwest Military, Inc.