• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Cabin Heater Hose Size

nobby

Old Timey Diesel Guy
Messages
473
Reaction score
117
Location
Long Island NY
Fighting a persistant weep on my heater hose. Can someone confirm that the front cabin heater pipes are 5/8" and 3/4"? The Tee at the top is 3/4 and so the black hose that goes to the smaller pipe is a reduction hose. Anyone got a part number for that I really dont want to screw around with reduction fittings and clamping a 3/4" hose onto smaller pipe aint gonna cut it. Best I can come up with so far is this:

Cheers
Nobby
 
I used a Pex ½x½x⅝" brass Tee from Home Depot, which provided a nice, snug fit for the two ⅝" heater hoses and the ¾" hose from the crossover (still used hose clamps). Then to replicate the flow regulator to the front heater core that's in the OEM plastic Tee, I took a ½" copper pipe cap, drilled a 5/16" hole on it, slightly flared the open end of the cap with the pein end of my 12oz ball pein hammer, then sweat soldered it closed end first into the ½" Pex nipple for the front heater core. Worked like a charm!
 
I used a Pex ½x½x⅝" brass Tee from Home Depot, which provided a nice, snug fit for the two ⅝" heater hoses and the ¾" hose from the crossover (still used hose clamps). Then to replicate the flow regulator to the front heater core that's in the OEM plastic Tee, I took a ½" copper pipe cap, drilled a 5/16" hole on it, slightly flared the open end of the cap with the pein end of my 12oz ball pein hammer, then sweat soldered it closed end first into the ½" Pex nipple for the front heater core. Worked like a charm!
That needs to be posted someplace important
 
Yeah my OEM tee's are still in good shape, I just need to replace the front core hoses. OEM are discontinued, the part guy gave me a full print out of the whole system and part numbers I'll post that here at some point. I have come up with the following Gates numbers:
18076 - 5/8" x 3/4" with a molded 90 DEG
28476 - 3/4" x 3/4" with a molded 90 DEG
I'll post if they work or not.

Cheers
Nobby
 
When I replaced the front heater core to the new homemade tee (because the plastic OEM one had cracked and leaked) I just used standard 5/8" heater hose off the roll I had sitting in the garage. The natural curve of the hose off the roll made for a perfect fit between the heater core nipple and the new Tee. I had some left over hose heat shield I slid over it to protect it from any heat radiated off of the turbo/exhaust pipes. Cost me only a few cents for the piece of hose instead of the almost $20 the molded piece of hose with the bend in it.
 
That needs to be posted someplace important
I had posted the same info a few years back in a thread about where to find the no longer available OEM plastic heater Tee for Suburbans. A couple of us mentioned using a Pex Tee. I just went as far as to also replicate the OEM flow restrictor so that the rear heater core got sufficient flow of hot water to it.
 
Back
Top