Jabsco Water Pump

[Van_Isle]

I have the raw water Jabsco pedestal pump off the boat right now to clean it up and replace the impeller. Couple questions:

1) What's the best way to clean the gasket surfaces on the pump body and backplate? The backplate is sitting in vinegar right now, and looking somewhat better, but I suspect doing the same for the body wouldn't be good for the seals! I might try inverting it into a shallow bath of vinegar so just the surface is submerged (I'm using cleaning vinegar).

I've seen one suggestion of using very fine wet-dry sandpaper taped over a glass surface for final clean-up.

2) There is a o-ring for the backplate, but the new impeller came with a paper gasket instead. The o-ring doesn't look like it's up for re-use (and the backplate was weeping). Will the paper substitute?

It's a Jabsco 2620-1001.

Thanks in advance!

[capnward]

I think I had too much raw water flow for the heat exchanger

Van,
I looked at the Jabsco 2620 spec sheet PDF online. See https://www.xylemflowcontrol.com/fil...43000-0495.pdf The pdf also has an exploded view and a parts list. The o-ring you may need is part number 18753-0125. Your Jabsco 2620 seems to have a groove in it for the o-ring, so you had better not use the paper gasket, unless you cant wait to get another o-ring. Definitely do not use a paper gasket with the o-ring, if you want it to not leak. It sounds as if you are trying to remove old gasket material, but there should have been no gasket there, and no need to clean the surfaces beyond a wipe with a rag. Only the o-ring with waterproof grease around it should suffice, with a well-fitting cover. As far as cleaning the old gasket material off, whether paper or gasket-in-a-tube, make sure you remove it thoroughly from the groove where the o-ring will go. Soaking in vinegar may help. Go over the rest of the surfaces with a putty knife, then some increasingly fine sandpaper on a glass or equally flat and smooth surface. Don't wear down the surface on the pump body too much, or the impeller will have too much friction on the cover, wear out quicker, and leaks will be more likely.
It's interesting to me that you are using a pump that moves 5.8 gallons per minute at 1750 rpm, and that it seems to work for you. For raw water, I am using a Jabsco 1673-1001 that moves 11 gpm at that speed. I used to have a Jabsco 7777-9001 that moved 23.3 gpm. It pushed water through a much larger heat exchanger that came with the boat, big enough for a 90 footer, I was told. When I changed to the Monitor heat exchanger sold by Moyer, I kept using the old pump, and after several years developed a leak at the saltwater exit of the HX. I had occasionally neglected to replace the zinc in the heat exchanger often enough, but I think the extra flow accelerated the internal erosion of the copper. The guy I hired to repair the HX said there wasn't much copper around the exit tube left to work with brazing. The repair didn't last, so I recently bought a new HX from Moyer. I bought the Jabsco 1673 because Moyer says in their catalog that it is comparable to the MMI 501 pedestal pump that they sell. I wanted to make sure the pump would fit on the old base, and could get Jabsco specs online. Your 2620 pump will probably make your HX last longer.

[Van_Isle]

Thanks 'Cap'

Interesting to see the range of capacities of the pumps that are cross-referenced in the Moyer catalog. My pump is the one supplied by the shop that did the rebuild on my engine. At 5.8 gpm @ 1750 rpm, it looks to be pretty close to the Oberdorfer 201M (at 1750 rpm: 6 gpm @ 0 ft of head and 4.8 gpm @ 20 ft of head). I would expect the Moyer 501 would be fairly similar.

[Van_Isle]

Hmm ... the guys that supplied the pump didn't have a o-ring. They were as surprised as I that there wasn't one in the package. But they felt the paper gasket would work. However, didn't give much confidence when the fellow suggested a belt sander for cleaning the gasket surfaces!