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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Scott & Heather on June 09, 2017, 08:15:39 AM

Title: Water pump rebuild or replace?
Post by: Scott & Heather on June 09, 2017, 08:15:39 AM
8v92TA "Walking" pump is what I think they call it.
I've read so much on here about rebuilding the water pump internals versus replacing the entire pump. My pump appears to be leaking and I am needing to remedy this. I have wet coolant coming down from somewhere behind the pump and then running down to the hose on the right of the photo, the lip of this hose still has coolant in it where it catches some of it in the photo. Should I buy a rebuild kit (and from where?) or should I replace the pump in this scenario? My pump doesn't have the bolts but rather a snap ring of sorts holding it in:

(https://uploads.tapatalk-cdn.com/20170609/4558b17afdb1b43919edec5503ccac31.jpg)(https://uploads.tapatalk-cdn.com/20170609/412a2f16b8072cf302c2ebcbee827edb.jpg)


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Title: Re: Water pump rebuild or replace?
Post by: TomC on June 09, 2017, 08:20:58 AM
Personally-I replaced the water pump on my 8V-71 with a rebuilt. I know that professional rebuilders aren't perfect-they can be sloppy and make mistakes too. Mainly on mine, you have to remove the radiator to get to the water pump (V-drive). On a T drive, the water pump is right there. If you have time, maybe tackle rebuilding yourself. If it continues to leak, not a big deal with yours. Many times, water pumps will leak when cold. Does it continue to leak when warmed up running? Good Luck, TomC
Title: Re: Water pump rebuild or replace?
Post by: Scott & Heather on June 09, 2017, 09:27:11 AM
Tom, i do think it does because I can dry out that area and then it will be wet again after a drive. It doesn't seem to be leaking a lot but I just want to RR it to be sure. I've had this coach on the road for 9 months so far and I've been slowly baselining it. Just did trans fluid and filter change, new air cleaner housing and filter, new tires all the way around. New bearings and brakes in the rear, (doing fronts this fall), new exhaust. Water pump, tstats, and radiator internal inspect and clean are on the list this summer


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Title: Re: Water pump rebuild or replace?
Post by: easystreet on June 09, 2017, 06:20:43 PM
If I remember right, the weep hole passage for the shaft seal cavity is on the back side of the pump housing at the housing to front gear case mating point. Thus when the seal starts to fail it leaks coolant to the outside at that point rather than forcing it past the oil seal and into the engine. You need to pull the complete pump. The snap ring holding the front cover is only going to get you into the impeller cavity area of the pump housing. You still need to get to the bearings and inspect the drive gear which are all on the back side which is sticking inside the gear case housing the pump housing is mounted to. My advice would be to order up a rebuilt exchange pump to cut your down time. They don't take that long to change out if it is out in the wide open as yours appears to be.
Title: Re: Water pump rebuild or replace?
Post by: Scott & Heather on June 11, 2017, 07:11:09 AM
Thanks Gil. Just what I needed to understand. So I'll just order a replacement/rebuild entire unit and swap it out at this point. Then I know I'm good to go. And yes my pump is out in the open and at standing height. Very very easy to get to.


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Title: Re: Water pump rebuild or replace?
Post by: B_K on June 11, 2017, 07:51:07 AM
Scott that is the easiest way to do it. (if the replacement leaks at least it will be replaced under warranty)

And BTW yes yours is a "WALKING PUMP" as it has one "LEG" forward and one straight down.
A "RUNNING pump" has one forward, one backards.
And a "STANDING pump" has both straight down.

OH and while you at it go ahead and replace those 3 hoses going to the pump and use new clamps too. (it will save you from a head ache in the near future!)
It is just standard straight hose. (If I were you I'd just order a "stick" of it and cut off the pieces you need and keep the rest in your spare parts box. {you'll use it again somewhere trust me)
;D  BK  ;D
Title: Re: Water pump rebuild or replace?
Post by: Scott & Heather on June 11, 2017, 08:32:53 AM
Perfect Bryce. I actually already have blue hose. I just need to wait until we settle in Iowa for two months to actually do the rr. While I have the coolant drained I'm going to replace tstats water pump, coolant hoses throughout, and pull both radiators to re-Gasket the leaking gaskets as well as look inside and inspect them for any scale or buildup and clean them out if need be.


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Title: Re: Water pump rebuild or replace?
Post by: luvrbus on June 11, 2017, 08:57:44 AM
Read the manual because you need to set the gear backlash when installing a different pump. 
Title: Re: Water pump rebuild or replace?
Post by: Scott & Heather on June 11, 2017, 10:24:09 AM
Oh no. I remember you talking about this. How hard is it to set the gear backlash? Why can't this be easy cliff :).


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