Sprint water pump rebuild risks

[cleverusername]

I have the pump out and the rotor at the top off. The shaft teeth are good, as are the splines for the impeller. What I am not sure about is the bearings, there might be a slight grumble, but it is hard to tell just spinning it by hand.

How risky is it to rebuild? If it is easy I will do it, but if there is a risk of lunching the pump trying to get it apart I am tempted to avoid the risk.

[SprintMWU773V]

Rebuilding a pump is not especially difficult but it easy to damage things, particularly the soft impellor and the geared shaft. If you're rebuilding the pump it make sense to replace the bearing.

You should also have the underside of the impellor turned on a lathe to give it a nice flat surface for the new seal to 'seal' on.

I do actually have a set of the factory tools to do the job but I assume you're not very local to me? I have refurbed several pumps without the tools and never had any problems so it is definitely possible.

[Jon Tilson]

There is loads on this if you trawl back through the forum and a wiki guide on the dolly wiki that I wrote some years ago.
The bearing is pence so daft not to replace it.
Also do the bush in the block but getting the old one out can be a pain.

Mahesh's resto thread has a recent pump overhaul.

You need good circlip pliers to get the bearing off the shaft. The spinner disc may need some persuading but be gentle and it will come off if you give the shaft a good clean up with wet and dry.

Gear Teeth on the bottom are the crucial bits...and the splines must hold the impellor with no rotation. Good impellor under side for the new seal to work with too.

Jonners

[Flyfisherman]

How risky is it to rebuild? If it is easy I will do it, but if there is a risk of lunching the pump trying to get it apart I am tempted to avoid the risk.

Have a read at teh attached then you can make your mind up what to do.

viewtopic.php?f=4&t=7214

Paul

[cleverusername]

Well I have it apart, not that difficult.

Once I had removed the spring loaded seal, just peel the top seal away. I would add two things to the guide, you decide if they are useful.

The cage is push fit on the shaft and is removed by pulling it over the gears. Wasn't obvious to me at first. I used a normal puller for that.

The bearing was a bit of a bugger, but I found heat was the best way of shifting it. Do not do this if you want to save the bearing for any reason, it will more than likely knacker it. Plumbers blow torch, heat the bearing for a minute and then a bog standard puller was more than enough to remove it.

Next step is rebuild when the kit comes.

[Jon Tilson]

Most of the time the cage stays in the block.

On occasions when it doesnt it needs supporting in a vice and drift the gear end of the pump spindle out of it.


Jonners