Coolant Hoses - the little ones

[Ncostello]

Since I'm replacing the radiator, upper and lower hoses and the thermostat... might it be a good idea to replace the smaller hoses in the system?



There are some around the oil cooler, the top of the engine on the steel lines, and down at the transmission cooler exchanger (and to those look fun!!!).



Does anyone have the P/N's for them? They appear to be the same... and two types. Straights and 90's.



Is this a Cummins only thing or Napa too?



With the alternator off and everything else... I have good access. I just hope I put the new hose clamps with some orientation that I can get to later if I need to re-tighten. Gotta remember to do that

 

[JGrefenstette]

i had to replace the 90* one on the top of the motor that runs to the steel lines for the heater core, the lower one need replacing now too. i got the 90* at advance auto, just take in the old one and match it up. the lower is just a 3-4 inch streight piece real easy to find. ive had mine sitting in the ash tray for 3 weeks now, just to lazy to slap it on. good luck.

 

[Shadrach]

The straight hoses ( 2 req - 1 for the heater and 1 for the trans cooler ) are Cummins p/n 3918267 and the 90s are Cummins p/n 3918266 ( 4 req - 1 for the heater and 3 for the trans cooler ) Shadrach

 

[Ncostello]

Thanks tons!!!

 

[bgilbert]

NAPA has them. If they are out of one of the 90*, ask them for any 5/8" heater hose for a different application that has a 90* bend. Cut and use.

 

[Ncostello]

Scheids wants $30EA for the 90's and $11EA for straights.



Lets see... 4x$30 and 2x$11. Thats $142 for those tiny hoses OEM. And thats rediculous. Just another example of excessive markup.



I think I'll pass on the Cummins OEM parts this time.

 

[Shadrach]

You could always buy the 90* from Dayco p/n 70001 and cut it too fit. I agree the OEM parts are sometimes too much $, but you got ask nowadays. Shadrach

 

[mysteryman]

The original heater hoses on the first gen trucks were silicone .

The cheap aftermarket hoses are not silicone. . The will not last nearly as long as the originals did.

 

[JDancoe]

Echoing Mysteryman-If you intend to keep the truck any lenth of time, bite the bullet and by the factory silicone hoses. Also, if you replace the clamps make sure you get the proper clamps for silicone hose. Regular run of the mill worm gear clamps will eat up silicone hose Jack Dancoe

 

[Ncostello]

Good points guys. Thanks. I did notice the hose clamps were fully lined such that none of the gear track would get into the hose jacket.



Knowing they are silicon long life hoses makes it worth the cost.



Were the upper and lower main hoses silicon also? Mine didn't appear to be but did look like perhaps originals... with 200K on them.

 

[KMUNCASTER]

fun with trans. heat exchanger tubes..

I blew a rear heat exchanger coolant tube this summer, just after returning from a long delivery, in a remote spot. It let go just outside my front gate



I had to completely remove all of the steel lines for the exchanger and installed rubber with lots of protective heat tape and did a re-route out to the inner fender just to be safe. If you are doing the hoses, give those tubes a few pokes, mine didn't look so bad from far, but were completely rotten. I then added the biggest transmission oil cooler that would fit in behind the grill just for safety.



You won't want to be doing a bypass on the road, do it at home and be safe... .

 

[Ncostello]

Ya know... I wondered about that too. One of mine up by the valve cover looks a little bad on the outside. And one of mine at the very back of the engine off the cooler makes a 180 turn and rubs against a bracket on the engine. It looks like its rubbed a small "knick" in the steel tube and will eventually wear through causing a leak.