M809 water pump and fan hub

[catskillpond]

Leak started where the fan hub mounts to the timing cover into the front timing cover. The adjustment bolt for the fan hub was missing and one of the hub bolts worked out and is rusted in place. Put a wrench on it would not move so im going to pull the radiator and replace all the belts and pump and fix the bolts.

Two questions are the pumps on the M939 series the same as the M809 series mine is a 1972?

If i remember the hub has two roller bearings anyone rebuild one figured good time to do it since it will be tore down?

Thanks for replies Scott

 

[country]

The pumps on M 809 and M939 are not the same

we have pumps in stock

Dave
www.easternsurplus.net

5T-666 | Water Pump with pulley
Water pump with pulley for NHC-250 Cummins diesel-engine Fits M809 Series - 5 Ton

Price: $225.00



5T-811 | Water Pump Belt
Water Pump Belt for M809 Series 5 Ton with NHC Cummins 250 Engine
NSN #: 3030-00-404-3061, 3030-00-253-8345
Part #: 202340

 

[juanprado]

I have spares of the hard to find water pump plate gasket to block if you need one. send pm.

 

[BigDawg41]

You should disassemble the fan hub,clean and repack both bearings.Its easy to do while you have it off.There is a grease seal on the backside of the hub that you should replace also since it might get damaged when trying to remove it to get the rear bearing out.When I rebuilt my fan hub last year the grease inside mine was really old and starting to harden and might have been original except from occasional lube at the grease fitting.Be sure to never sieze the water pump bolts and copper gasket for future removal or belt adjustment.

 

[catskillpond]

Tore it all apart today bolts were completely rusted even in block got down to the pump mounting plate that mounts to block. Does anyone know if this mounting plate has a flange that sits inside of block?
Soaked it down and tapped all around but would not break loose let it soak overnight. Im told there is a paper gasket from the block to the back of the plate, what about black RTV silicone to replace gasket? Thanks for the help Scott

 

[catskillpond]

Also tore the fan hub apart goin to install new races and bearings anyone know if the rear seal is available at NAPA Thanks Scott

 

[73m819]

On the fan hub is a plug, pull the plug and install a grease fitting, on all civi units, there is a grease fitting, do not over grease, because it will go every where.

 

[juanprado]

Yes, The ring that supports the water pump is part of the plate and goes into the block 1/2-5/8 inch. I used a flat 2 prong nail pry bar as it is thin on the end. A few soft taps and it wedged itself in and I used it all around to gently work the plate off.

Pics from yesterday doing the same thing.

 

[catskillpond]

809 fan hub seal part#

Im posting part # seal for the rear hub fan NAPA 17387 cost $ 9.00 Scott Also note when putting washer on shaft it does have a flat spot inside that has to set on flat of hub shaft. Took 15 minutes to realize that could not get the cotter pin in but no one saw that brain storming session. Seems we dont have the patience when we get older?