Replacing Seal on 3YM30 Seawater Pump

[sea_casper]

My Yanmar seawater pump started leaking, I removed it to disassemble to replace seal. however I cannot remove second nut on shaft, the one inboard of pulley, it has a curved arrow on it pointing CCW as viewed from pulley side.

I suspect it is Left Hand Thread since it doesn't want to loosen in the normal way, the pump is made by Johnson AB (Sweden) and is a F4B-903.

Does anyone have any direct knowledge of this pump, and the disassembly procedure, the Yanmar service manual has no specific instructions.

 

[seadaddler]

Yes

Just replaced the seal on mine and it is a reverse nut and decided to replace the 2 bearings also even though they seemed OK.
Mine was on my 07 3YM30 H-36
Nick

 

[sea_casper]

Just replaced the seal on mine and it is a reverse nut and decided to replace the 2 bearings also even though they seemed OK.
Mine was on my 07 3YM30 H-36
Nick

Thanks for confirming, if you turn it the "right" way, it's easy, using a flat blade screwdriver you can push the old seal out from the "weep" slots. I want to inspect the bearings and shaft but the rear bearing doesn't want to pop out.

I know you can order replacement parts from a Johnson Pump distributor for less than Yanmar prices.

 

[Ken13559]

Rear bearing is held in place by a cir-clip. Remove the clip then tap the shaft from impeller side and the whole shaft assembly should come out.

 

[sea_casper]

Rear bearing is held in place by a cir-clip. Remove the clip then tap the shaft from impeller side and the whole shaft assembly should come out.

The pump blowup shows a inner cir-clip which retains the inner bearing (and shaft?) There is some corrosion around the outer bearing which seems to be retaining it, tapping on the shaft does nothing, I am soaking the bearing edge with "Blaster" to see if that helps, I have already removed the outer cir-clip.

 

[Ken13559]

The larger retaining cir-clip need to be removed before the shaft could be tap out. The smaller cir-clip is there to hold the smaller bearing in place. You can remove it later after the shaft assembly (bearings, spacer...) comes out.

 

[sea_casper]

The larger retaining cir-clip need to be removed before the shaft could be tap out. The smaller cir-clip is there to hold the smaller bearing in place. You can remove it later after the shaft assembly (bearings, spacer...) comes out.

And indeed it taps out, after I soaked the outer bearing pump joint overnight with penetrating oil.

Post mortum shows significant shaft wear in the vicinity of the seal, and corrosion build up on either side of the seal contact area, the inner bearing spins freely and smoothly. the outer bearing is "stiff" but turns smoothly.

The seal itself appeared to have a coiled spring that was partially disintegrated.

I had hoped to rebuild pump and save as spare but when you add up replacing the shaft, both bearings and the seal, you are almost to the price of a new pump.

Thanks Ken, for your help, I appreciated your responses.

 

[kloudie1]

Sea-Casper.. Lots of times the shaft can be cleaned up and saved with this;
http://www.skf.com/group/products/s...als/wear-sleeves/skf-speedi-sleeve/index.html
The bearings are standard sealed bearings as are the seals so they can be obtained at a place like Motion Industries.. The old seal will have numbers that can be cross referenced so if ya take the pump parts and bearings and seal to a supplier he can get the new parts for ya usually at a considerably lower price than the pump company itself..

 

[Ken13559]

Just about the parts i buy from Yanmar dealer is the shaft. Rest of parts like bearings, seal, o-rings and cir-clips i get from auto spare parts shops. Very cheap to rebuild.