HP Bravo lwp drive going through water pumps
 

I have the Merc low water pickup drives on the Donzi, the ones with the water intakes just under the bullet. For some reason these things seem to go through raw water pumps like crazy (525 SC's). Almost since new it seems like I burn up a couple each season and always its difficult to prime first time out each year. Is this setup prone to this problem and will switching to transom mount pick ups help?

ITS the west end of erie.... do they make silt strainers?

Is this the stock set up with the black plastic housing ? We never change just the impeller out as internally the housing will wear so your tolerances will be off which can cause priming issues and water flow issues. We change out using the whole kit - new housing, wear plate, impeller and so forth.

We have better results using the Mallory Marine Bravo water pump Impeller kit rather than the OEM Mercruiser kit. The Mallory housing is better finished out internally as it does not have all the internal slag flashing like the mercruiser housing. Allso the Mallory housing is stronger built for one it weighes more plus it has a bigger inlet port and a bigger outlet port for flowing more volume of water.

I know you would know that a sea strainer would help - as they do so hopefully you have them for helping to keep out the trash / sand out the cooing system. Also if your X dimension is too high you could be catching some water aeration from the water flow off the transom. Aerating water to the impeller will wear them. Also never use an oil base product nor any form of grease when installing a new impeller.

FYI Mercruiser and Sierra brands are the exact same bravo water pump kit

The seapump is the same on the 525SC as all other Bravo packages so thats not the issue. I never had problems with mine on the Pantera, but I had a hull pick up.

I would backflush the drives from seapump input hose and check the flow also.

I always put the whole kit on with the new housing and everything. Since new this thing has always seemed to be hard on raw water pumps. Its 100% stock oem with no strainers. I have checked several times and there never seems to be any restriction. I just wondered if anyone else had issues with the lwp lower. I think i may put transom mounts on it this winter as the motors have to come out for that. There is zero room in the bilge to work. Maybe strainers to but i have been told they dont do much good with the silt type bottom we have.

I switched to the Hardin stainless housing and after 2 full seasons it still looks like new. You may have a suction leak which could cause your problem also. If you go with the stainless housing, I recommend taking a die grinder to the internals and polish all the edges. You will probably need to cut the 90 off the outlet hose and put a threaded 90 on the pump to clear the motor mount.

If your driving it aggressively, I'd imagine it airs out a bit and loses suction quite often. An added benefit of sea strainers is the reserve water capacity when the pick up comes out of the water. Unless your running right on the shoreline in 3' of water on the regular I don't think silt is the issue.

I have always put on a little grease to help priming - what is the problem with grease should I stop?

Have you had a failure yet because of it? Neither have I so I wouldn't worry about it

Petro based lube and the rubber are not a good mix, lube it with some dish soap when you install the impellor, does same thing but will not harm the rubber.