I think I might need a new water pump. Does it matter what brand I get?
Genos has Cummins pumps and gates pumps. The Cummins pump costs a lot more. Does anyone know if it is a better pump? Thanks

 

I don't know about Gates water pumps, but 23 years from the stocker point me towards picking the Cummins one..

What's the matter with yours?

 

I don’t know. Maybe nothing. It just started running hotter than normal and I was wondering if maybe the water pump was getting weak

 

It seems more likely the cooling system's circulation might be blocked instead...Check for leaves and debris in front of the radiator, then check the radiator temperatures at both top and bottom with an electronic temperature gun...If the top is a lot hotter than the bottom, you may have some stopped up tubes in the radiator core...You can use that same tool to check temperatures anywhere else you might suspect an obstruction...Check that your fan clutch is operating correctly too......Ben

 

Ok. Thanks for the info

 

Is there a good test for the fan clutch?

 

Listen for it to engage and disengage...When it does note the temperature...Also when it's hot enough to be engaged, with the engine off, you should not be able to turn the fan blades easily......Ben

 

Thank you

 

Check the thermostat as well. I've seen cases where the thermostat failed, which didn't allow the thermostat to open fully. It would allow enough water to pass to keep temps OK, but if it got hot outside or you loaded it up, it couldn't keep up.

 

Looks like most of the bases have been covered however a few things

Unless the pump is slipping on the belt or the vanes are disintegrating in the pump it isn't weak

The thermostat replacement not a bad idea just for peace of mind unless it is relatively new

Could be the radiator cap is not holding its pressure like it should

I used a gates replacement pump from genos when mine started leaking. It is still going with 200k miles on it with no issues so I would not be afraid to use one myself.

A very common issue with 2nd gen trucks is the radiator getting gunked up as the oil blow by tube has a tendency to get oil mist on it which then collects dirt thereby reducing airflow. The only good way to clean the radiator is to pull it out as you are not going to get much out from the front since the inter cooler and ac coil are in front of it and you just cant get a good spray angle from the rear just not enough room. It is certainly worth a try though. Use something like simple green or purple power etc spay it good let it soak a bit then hose it out. I know when I took mine out to clean it as doing it in the truck just didnt do much but you may have better luck., I was quite surprised how much grimy dirt came out and subsequently worked well for a couple more years until it sprang a leak and had to replace it.

 

Well thank you guys for the replies. I appreciate that. That’s good information. You guys helped me decide what to try to get it cooling good again. I think I will try to find a good quality thermostat and maybe a new cap and fan clutch.
Thank you, Marv😎

 

I just fixed a 97 that was running hot- flushing the cooling system with water and citric acid to get rid of the gunk in there, flushing again with dish soap, checked the outside of the radiator (which was clean) and new Cummins T-stat and coolant.

Everything back to normal.
With a bad T-stat your fan clutch will not engage because the air coming from the radiator isn't hot.
I usually put a drop of penetrating lube on the shaft of the bi-metal spiral of the fan clutch.
Could fix some bad ones by doing this, if the shaft is sticking the fan clutch won't work properly, in some cases not opening correctly and increasing fuel consumption.

 

A few years ago, I bought a Cummins water pump for my Ramcharger project. After receiving it, I saw it was made in China for Cummins.
I try to spend my money local, or if not, at least made in the USA whenever possible. Since there where no other US made options, the last three I bought and installed where from Geno's and they where the Gates ones for a 1/3 of the price of the Cummins part.

All of them have been working equally well. on different 12V motors.

I agree, if your truck is just not cooling as well as it used to, it is not likely that the water pump is the issue. Those usually work fine until they leak.

 

I've only ever replaced a water pump after the seal goes and starts leaking. All good measures listed above.....