PDA

View Full Version : Leaking dash heat circulation pump



Denny
05-26-2013, 11:34 AM
My Prevost dash heat circulation pump is leaking and I have replacement parts, seals, impeller, gaskets, etc. I ordered from Prevost. I have removed the pump and cannot disassemable it. Can anyone tell me how to remove the impeller to get at the seals? Prevost has an upgrade in a seamless motor/pump setup for $800 but I opted to repair mine for $100 in new parts. Now I am stumped. Any help would be appreciated. This is the pump located on the ceiling in the front center bay

Joe Camper
05-26-2013, 04:57 PM
pictures please. Have U even gt the housing apart or no.

Denny
05-26-2013, 07:48 PM
Photos of pump

Joe Camper
05-26-2013, 08:08 PM
Have U attempted to seporate that next flange that couples the pump housing to the motor housing?

Im guessin the impeller is what U R dealing with now.

Hate to sound fussy but how bout another photo.

The snail the impeller take a photo of that. Is it held on the shaft with a small nut? Is the impeller aluminum or metal?

Im pretty confident I know U well enough to say if U cant figure it out its a bit of a jig saw puzzle hu?

Bet U R happy that big black Mack aint this fussy.

gmcbuffalo
05-26-2013, 10:30 PM
Call these people


P M Pump CO (http://www.manta.com/c/mmgj6jn/p-m-pump-co)Pm Pump Company
5032 Stanley Farm Road
Salem, VA 24153-7948 map (http://www.manta.com/cmap/mmgj6jn/p-m-pump-co)

Denny
05-26-2013, 10:51 PM
Will send additional photos tomorrow. I cannot separate the brass pump section from the motor part because the impeller is holding it together. I have tried prying between the brass pump and the motor but nothing moves. I believe once the impeller is released it will all separate so I can replace the seals. It seems to be pressed on instead of a nut holding it on the shaft.The Black Bull Dog is simple compared to the bus.

I will contact the pump company on Tuesday. Thanks for the help.

Gil_J
05-27-2013, 11:34 AM
It looks the same as what CC installed for the Webasto. If so, get a bigger hammer. The impeller is just stuck. Once you have the motor off you can press or beat it off.

Pete
05-27-2013, 11:36 AM
I would think that there should be an allen stock screw holding the impeller onto a slotted shaft. Check closely, it may be covered by sediment/rust.
Good luck in getting it off!

Gil_J
05-27-2013, 07:25 PM
Here's what mine looks like off the motor. If the same there's set screw. BTW, I bought a replacement for about $400 and when I get around to putting this one back together it will be my spare.

11164

Denny
05-27-2013, 09:37 PM
Gil,
My pump is not the same. It is not a converter added pump but one from Prevost. I believe we all have them in the front bay behind the bumper. You have to crawl in the bay and look on the ceiling to find it. It aids in circulating the "water" from the engine compartment to the front of the bus. I checked online on the Prevost site, under Maintenance Manual, and it requires a puller that is available from MP Pumps, the manufacturer of the pump. There are no set screws on impeller.

I have a MP dealer about an hour from me so tomorrow morning I'm going to call them and see if I can get a new one and rebuild this one to keep as a spare. MP Pumps has a list price of $522 on their website so I'm hoping to get it for less using my company. MP is in Michigan but this dealer is only an hour away so I hope I'm taking a trip to get it in the next couple of days.

Thanks for all of the replies and help. I will let you know the results when the pump is on. Again, thanks to all.

Gil_J
05-28-2013, 07:27 AM
I meant to say there is not a set screw. I think the converter and Prevost pumps only differ in their water fittings and voltage. I too should have used a puller, but was able to use a mallet without damaging the shaft. Even the converter one that is commonly used in school buses is expensive.

I'm curious, how much coolant came out when you removed the pump?

Denny
05-28-2013, 08:07 AM
I shut the valves off in the engine compartment and collected about 5 to 6 gallons of coolant. Fortunately there is enough room to get a five gallon bucket in the compartment. I hit the pump many times with a brass hammer and it would not move.

Gil_J
05-28-2013, 09:41 AM
Thanks Denny. That's a lot more coolant than I would have expected with the valves closed. Good to know.

Joe Camper
05-28-2013, 11:06 AM
Denny not everybodys is in the same spot as yours. Some are located on the ceiling of the first bay in the center of that ceiling and on my bus with OTR A/C it was in the evaporator bay 3rd bay drivers side.

Denny
05-28-2013, 08:57 PM
Thanks for the info Joe. Did not know that.

Still waiting for info from the pump company.

Denny
06-04-2013, 04:53 PM
Finally got the circulation pump running. After going back and forth for a couple of days the MPPump distributor got the correct numbers and ordered the pump/motor assembly. By using UPS red tag service the building process was reduced from a two week lead time to three days with overnight shipping. Order placed Thursday and received pump this morning. It is installed and running. I have attached a photo showing new pump in place.

Still not sure how to get impeller off of old pump. MP Pumps is trying to figure out which puller I need.

Denny
06-04-2013, 04:58 PM
11178

Oops. Photo of new pump for above post.

dale farley
06-04-2013, 09:56 PM
Looks good Denny. Always nice to have the problem solved.