I need to replace the heater core in our 24v dually, we're getting coolant in the cab (fun fun).

I talked to a customer of mine that has a 97 12 valve, he said he's replaced 3 heater cores in his truck. Apparently after he replaced the third one he was talking to someone that said a restrictor is made that goes before the inlet of the heater core, which will reduce volume & pressure into the heater core.. and that Cummins equipped Dodges are notorious for blowing heater cores.

Is there any truth to this, and if so where would I get this restrictor? I only want to do this once!

Thanks for any input!

 

The nipple on head that feeds heater is special. The restrictor is built into this nipple. You could get 50 PSI or so into heater core and generally makes a buzzing (?) sound wihtout special nipple.

 

So there is a restrictor built into the truck stock?

 

AC Delco has flow restrictors, their number for the 5/8in size is 15-5423.

I used to have a 1986 Ford F250 where I had to change the heater core every two years. I think it was excess flow that eroded the core but I never did put a restrictor on.

 

Out of 5 CTDs all with above 100,000 miles, most over 200k, I never had a problem with a heater core.

 

Alot of heater core failures are more related to the acid content of the anti freeze.Flushing every 3 (green) 0r 5 (red) will help alot & using the right mixture,also usually you get what you pay for in cores-go cheap-be prepared

 

I was flushing the cooling system every three years and the cores were made by Modine, hardly a bad brand.

 

The real problem is the configuration - those long thin brass tubes exit the firewall and are connected with short sections of rubber hose to the hard steel tubes which are rigidly attached to the engine, just fine for the gassers (patooie!) - it's that violent death-throe the Big Six goes thru at each shutdown that causes the break at the heater core - improper coolant use and ignoring the maintenance schedules may contribute, but it's that 359 that does it every time.

Solution? - Cut the brass tubing back to the core to a suitable length for connecting the hoses, run the rubber hoses thru the firewall and inside the cab, tighten the hose clamps, making sure they don't interfere with the cable-operated door levers, reassemble everything inside, cut the hoses to the proper length for the tubes on the engine, clamp'em, top it up, and yer good to go................

Oh, yeah - use the correct antifreeze in the correct blend, and don't fergit to follow the indicated maintenance schedule - that'll work fine, last a long time.

 

Gmctd. I did have the Big Six in my F250.

When my heater cores started failing I did consider the stress on the brass tubes as a cause of failure. What I did was to make the inlet and outlet hoses about three feet long and formed a big loop with the hoses so that they passed by the base of the battery. I then clamped down the hoses to the plastic apron(inner fender liner) so that engine movement did not transfer to the heater core. My core life did not improve at all with that work.

I had to change the rad once during the ten years that I had the truck but I had to change the heater core four times. I was leaning towards erosion from excessive coolant flow as the cause of damage to the core, but, before I got around to putting a restrictor( I was just going to use a ball valve partially closed), I scrapped the truck and bought a new 2006 GMC Sierra.