No More Water Pump Leaks When Tightening The Fan Belts

[Rifleman]

Well, as we all know when you go to tighten your water pump belt on the Cummins 250 you always run the chance of a water pump leak when your done. Since i needed to tighten my water pump belt i spent some time today looking at the front on my engine looking for a better way to do this job.

I notice a tapped 3/8X16 threaded boss on the drivers side of the engine. After finding that boss i though why not try and make up an idler pulley to take up the slack on the water pump belt. This way with the idler in place there is no need to even mess with moving the water pump anymore.

I then spent the next two hours working on making a bracket to mount a leftover idler bearing from my daughter in laws car. I took some measurments on my truck, grabed some material and started machining. In the photos below you can see what i came up with. Please take a look and let me know what you think.

 

[mahdey]

that's awesome man.

 

[wrenchturner6238]

Looks like that should do the trick.

 

[Tow4]

Nice job!

 

[m109a2]

You know what you did is right on,I know what you did is right on.Everybody knows what you did is right on.Thank you for sharing

 

[goldneagle]

Is it spring loaded or is the 1 bolt holding the pressure on the belt? Are you planning of selling these to members?

 

[juanprado]

Wow! That is an awesome idea to a real need and a major failure of design engineering from cummins on this engine series. This belt and water pump change is a real pia.

Can you tell us more if you machined the bracket from an existing automotive idler pulley and bracket from what year and model or did you build it from scratch?

The pulley part is doable as most idler pulleys are sold as a replacement pulley with bearing only or as a complete assembly.

 

[Rifleman]

Goldeneagle, just the one bolt, no spring, all you have to do is just rotate the idler down into contact with the belt and tighten the bolt, easy as can be. I added the extra lock nut on the end of the bolt just to be sure that it doesn't come lose. As far as selling them i hadn't even though about it, the most expensive item of the whole idler would be the bearing. Now if you would like one then PM me, and if there is enough of a demand from other members i will work up a price and post a ad in the classifieds .

 

[Ord22]

I don't see anything holding the pulley in place, besides the bolt. Normally, There is a dowel pin made in the pulley housing that will sit in the bracket that it is attached to. This will help the pulley to stay in place under pressure. I don't see the dowel pin at all. I'm afraid that over time, the pulley will come loose and chaos will occur! I work on trucks for a living and I know that a dowel pin is made into the pulley housing.

 

[Rifleman]

Juanprado, the bearing is a factory piece from a late model Hyundai and as i said in the thread it was a left over from my daughter in laws car, but the mounting bracket is all mine. I have been doing custom fab work for years and have a full machine shop at my home so i just took some measurements and made the bracket from scratch. As i posted in the thread above if enouht members would like one for their truck i will work up a price and list them for sale in the classifieds.

 

[Rifleman]

Ord22 To address your question of a dow pin, no there is no dow pin. The bolt is threaded into the front cover and on top of that i added a lock nut onto the back of the bolt to make sure it doesn't come lose. Now if it did come lose the belt would push it up out of the way so it wouldn't cause any problems. I guess if i were to make these for sale i could just cross drill the head of the bolt for safety wire, then the end user could just safety wire it after they installed it, that way you know for sure it can't come lose.

 

[Artisan]

PM me when it is out of R&D and FOR SALE

Outsidedabox!

 

[5tonman1971]

This is awesome, and I defiantly think you should market this item! you can put me on the books for 5 of the brackets I can acquire the pulleys.

 

[doghead]

Ideally a tensioner is installed on the "slack"side of a drive belt or chain.

You have it on the "drive" side where tension always pulls it tight. This adds to the stress on your tensioner and mount.

 

[Rifleman]

doghead I understand this may not be the best place to mount this but like we always say, every thing on these trucks came from the lowest bidder, and Cummins design on how to adjust this belt sucks! So i am just trying to come up with a fix for their poor design, but if you would like to help me with my design, then please, PM me your ideas, i am all about team work.

 

[doghead]

Personally, I prefer to maintain it as designed(same as other commercially used Cummins water pumps).

That way, if I have a belt failure, I know all the fasteners are in good working order and the water pump surface is easily cleaned and lubed to reseal whenever needed.

I was just pointing out the biggest issue I saw with your idea, to educate you or anyone else that reads(anything on the internet) and says"great idea, I must do that" without any understanding of the proper way to tension a belt with a fixed idler.

No criticism, just trying to be helpful.

 

[Artisan]

doghead for President!

Hmmm, certainly changes things doesn't it...
I shall have to find a good water pump how to thread I thunk.

 

[Rifleman]

Well, some members were concerned that my idler lacked strength since it was being mounted on the drive side of the belt. So i went back and made some changes, I added a jack screw adjustment piece made out of 1 1/4" X 1 1/4" X 1/4" angle iron so now the mount is good and firm. Please take a look at the new photos of the updated water pump idler 2.0.

 

[Tow4]

Nice fabrication.

 

[Rifleman]

Tow4, thanks for the complement, i have been doing custom machine work for most of my adult life, it kind of helps having a complete machine shop at your home.