12v71 impellor change

Purchase the impeller puller it makes the job the way easier, take off the end plate and it's fairly easy from there,

Putting a lubricant on the impeller and housing always helps. I generally use dishwashing soap because it's handy and it won't harm the rubber. Warming the impeller will make the vanes more flexible and easier to install.

I use a tie wrap on the end to squeeze the vanes then as it gets pushed in the tie wrap slides out along the vanes, that with some lube works real well. The first time you have trouble pulling one out you will wish had a puller.

A puller doesn't help get it in........I put a lot of super lube on the housing and shaft, and get it started and push it in.......you should lube the housing when putting an impellor in regardless. I've also taken a flat piece of wood and then tapped it in lightly with a rubber hammer, if they get stuck half of the way in......the trick is, once it's started and you start pushing it in.....try to push hard and get it in, in one shot......

Getting them out, I've found that with the seacock off and the wear plate off, I spray a good amount of a light lubricant such as corrossion block all in the housing and center, then bump the motor twice and the impellor usually pulls out fairly easy......

I would suggest very strongly, you consult a DD service dept. that info is critical to proper operation of the engine, any incorrect info obtained on an open forum could be very costly, not that there are not competent people here, but, for something that critical, go to the source.

+1 to all that. Just use one of the very large tie wraps and lube.

And make sure you fold the vanes over in the right direction. If not they could break or be compromised when the engine is started.

FWIW, after all these years Tom I haven't found that to be the case. As long as the impeller is well lubed and you bump the engine over a tick to set the blades in the right direct, I've never seen an impeller have a blade issue from incorrect orientation of the blades at replacement.

One look at the old impeller before removal tells you which way to set the new one. I also like the tie wrap technique.

I have also found that blade orientation doesn't have any effect on longevity or anything. I bump the motor over once or twice, then start it......all is well......

You can also use a hose clamp to compress the vanes to get the impeller to go in.

Exactly what I do

Hi,

If you are completely stuck get a pair of verniers and measure the heights of the Injectors prior to pulling them out.

A Timing Tool is not that hard to improvise as long as you know what height they should be.

I once lost the tool on the way to a job and made a 1.484" tool out of a 2.5" bolt and two nuts. It took a couple of goes to get the nuts tight at what I measured to be correct.

The engine fired up and ran fine all the way from Papeete to Panama with no Injector or other problems other than a few failed drive belts for a layshaft that drove too much for the belt size.

I found the tool when I got back to NZ sitting on the floor of my car where it must have fallen when I was getting the rest of the stuff ready to go. I still have it although it has not been used by me since.

round off [not much] of the sharp edge of the housing on the pump...