Hey guys, got my motor rebuild and need a new water pump. Anyone recommend any specific brand?
rockauto has us motor works at a decent price with all the gaskets needed. The fins are a bit different.
warranty says 12months but also says limited lifetime warranty.

 

with that one you need to put your pulley on it, and sometimes you need to grind one of those ribs..

Mazda pumps are available, but not in the USA, so you need to use a Japanese vendor

 

@j9fd3s thanks. I was told to just replace the water pump when installing the rebuild motor. I actually have two original water pumps. Just dont know how many miles they have. The one i have off looks good and just a little rust but the fins look great.



I found a picture of the Japanese made water pump and look identical to the one i have.

I think im going to run the same pump. Just clean it up and maybe paint it to prevent rust.
Would it be best for me to rebuild this one it gives out. I have a spare that looks identical in case it does wear out.

 

You can use the spare one you have but sometimes if they have set dry for a long time they don't last very long before they start leaking from the weep hole. The seals inside dry out and on't last long once put back in service. As for a new pump I had been running Remans from O'rielly and using the lifetime warranty when they failed typically somewhere between 50 and 100k miles. They don't have remans anymore so Iguess I'll be buying a new one next time as well.

 

here is a list of part numbers, happy hunting

 

I went over and glanced at Rockauto. If it were me I think I'd just get the cheapest one with a lifetime warranty which looks to be the Gates.

 

So, how do your water pumps usually fail? Bad bearing? Leaky seal?
I've been running the original Mazda water pump in my S5 for the past 32 years or 370k+ miles without any issues. I would suspect, given the poor quality of replacement parts these days, nothing would match the service lifetime of my original pump.

 

@Dak it looks like the US motor works also has
lifetime limited warranty on their mechanical pumps. I dont like that the fins are slightly different. I wonder if it will still cool the same or maybe press out the fins and replace with the original fins. It does look new and not remanufactured.

 

@Hot_Dog this is the reason why i rather use the original pump i have. It only sat for 8 months while i waited to got the extra funds to get motor rebuild. The motor I had was remanufactured and had only about 60,000miles. No extra play on the water pump nor any sounds. So this water pump could go another 150,000miles then.

 

I'm gonna say leaky seal as I don't recall any abnormal noises and they spin fine when removed. Usually thy just start leaking out of the weep hole. Man that's a long service life. My original OEM pump only made it to 170k. Next one was a used one off my parts car but it sat dry for an unknown amount of time. Lasted 10 to 15k then started leaking very badly. Next was the reman which lasted around 50k and started leaking. My beast guestimate from current miles on the car and all these mileages is my current one has about 85k miles on it. All that said I do have some noise coming from the engine now( when it's cold) that sounds like bearing noise that I need to investigate. Only thing driven by the engine currently is the Alt, P/S and water pumps. Coolant temps are fine on my autometer gauge though.

 

I don't know what series your car is but if it's S5 unless you have an aftermarket gauge you'll never be able to tell as the stock gauge is pretty worthless. I'm thinking it's not worth the effort to swap them.

 

Yeah its an s5 na so no worth replacing the fins then. I think I might purchase the us motor works. Hopefully its last long.

 

so the seal is B630-15-120 and its available in Japan (notice a pattern? Mazda USA's parts side has no parts). the bearing isn't available, so if its bad you are SOL.