Jump to content

Recommended Posts

I have a 1950 Mack A20 with an EN354 straight 6 gas engine. There is a hole in the water pump housing. I need advice on how to make a repair or locate another pump..

 

Thanks

Chip  

Mack water pump hole.jpg

Link to comment
Share on other sites

Which side of the seal is it on? That looks like it could be a "weep hole" to allow any coolant that gets by the face seal to drain out and not destroy the bearings, also to vent air from the bearing cavity when there are temp changes. If you have a lot of coolant leaking from it than the face seal is shot.

 If I am wrong and it is on the impeller side of the seal, then disassemble, clean the casting and braize shut.

  • Like 2
Link to comment
Share on other sites

the  "adjustable " grease fitting should be on top making the hole on lower driver side, which would make sense it's location. however it does appear to be a rough cut slot or just ruff housing  casting. 100 % agreement with Geoff = purpose of the hole. what we are NOT told is whether it is leaking or just noticed the hole, by picture it could be clean from leaking or washed for photo session.  if it had bad bearings on pump shaft to carve that channel;  there should have been some serious noise at pump. take belts off and check wobble of pump shaft for quick diagnostic 

  • Like 1
Link to comment
Share on other sites

small piece left side of vent hole is the challenge. could be the work of an impeller; but hole is to clear cut. BMT " doctors "require more specific info please. is it leaking / does it wobble, and thanks for picture does help a lot.  the brazing part ?????🙄

  • Like 1
Link to comment
Share on other sites

Yes, I was thinking the same thing back in the day they all had a weep hole that’s what it looks like. There’s lots of places around. I would check Google search. For your area It’s just a bearing and a seal. Good luck.bob

Link to comment
Share on other sites

  • 2 weeks later...

The weep hole is on the bottom side of the water pump, I think, but I don't really know. In the attached pic with yellow arrow is the (weep hole?).  The damaged or cut area has blue circle.  No noise or wobble from the water pump.  The damaged area looks like it's on the shaft side and not the impeller side.  Thoughts?

Thanks for your help.

Chip

Mack waterpump and housing.jpg

Mack waterpump with damage and weep.jpg

Link to comment
Share on other sites

I’m not an authority on those. I can’t say but there’s lots of used parts. You might wind up buying a used pump somewhere could take some searching but as I said, there’s lots of those engines around especially with fire apparatus good luck… bob

Link to comment
Share on other sites

My thoughts are:

If it isn't leaking why worry?

If it is, I would note how far the pulley flange and impeller are pressed on the shaft, then disassemble. with the shaft and bearings out of the housing you can assess the housing, and what went wrong.

New bearings and seal and any repairs needed.

 Really only way forward on something like that.

 Waterpumps are fairly simple devices. The only caveat is to be careful not to damage the impeller, housing or shaft when taking apart. Make a puller to pull the pulley flange off, look at the impeller for puller holes, if there are none, the likely the shaft and impeller can be pressed out the back together and separated on the bench if you even need too. Going together make sure to press the flange back to the same depth while supporting the impeller end, the depth is what puts the preload on the shaft seal.  NO HAMMERING. 

 Did my share on the British Buses when parts were not available, or at least not readily available on this side of the pond. Industrial pump seals are made in most types and sizes and it is a good bet the Mack pump uses one of them.

  • Like 1
Link to comment
Share on other sites

sure I'm wrong = will blame bad eye sight this time. that yellow circled hole don't look like any weephole I remember. blue one more like it. other then the tab on the blue hole looking as though an impeller had something to do with it. no leak or wobble ?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...