Does Coolant Circulate Thru Heater Core at All Times?

[renovate7]

My heater core just started leaking. Fluid on passengers side floor and under vehicle. I've read all the threads about aluminum vs copper and not sealing to the box...Does fluid circulate thru core at all times? I'd like to let this go for a little while and work on other things that need attention. If there is no shut off valve, I don't see one, can I take off the 2 hoses and couple them together?

 

[Tow4]

can I take off the 2 hoses and couple them together?

That's what everyone does when the heater core starts leaking. Well, remove one hose and plug the other hose into that fitting. You can usually get the 5/8" hose over the 3/4" nipple.

 

[rtk]

Yup , do the "BYPASS" until you have time to fix it . Some use a piece of copper pipe , what ever works .

 

[juanprado]

Several ways to tackle.

Gates makes a plastic 5/8 to 3/4 barb double nipple and they also make rubber caps to close off the hose barbs at most real parts stores.

NBH 9811 is the napa part number for the fitting:
http://www.napaonline.com/Catalog/C...ctor-Reducer-Connector/_/R-NBH9911_0427134567

 

[SLOrazorsedge]

There should be a shut off valve at each heater hose union. Its a simple brass screw down gate valve. Just went thru this with my M936A1. Removed the heater core in about 20 minutes and had it repaired at a radiator shop for $55.

 

[Skinny]

It literally takes less than an hour to replace the heater core and burp the cooling system. Suck it up and just change it. I kept milking mine because I felt like it was going to be a long painful repair. It takes longer to install those valves or bypass the core then to just get it over with. Although I do understand being in a pinch or not having access to a replacement part.

Dont be scared...it is nothing like doing a heater core in a modern car.

 

[DUECE-COUPE]

mine went out on the interstate, took the hoses loose from the heater core, went to a bush on the side of the road, and cut a limb larger than the the inside diameter of the largest hose. wittled away at the section till it fit in both hoses, and used the hose clamps to seal them off. got me back on the road in 20 minutes. better than walking!!!!

 

[renovate7]

Just ordered a Spectra core from Napa. Should be here Monday.

 

[Warthog]

There should be a shut off valve at each heater hose union. Its a simple brass screw down gate valve. Just went thru this with my M936A1. Removed the heater core in about 20 minutes and had it repaired at a radiator shop for $55.

No shutoffs on the CUCVs.

 

[zout]

Those fellas ^^^^ up there pretty well covered the shut off issue. If you do wind up installing shut off valves remember the coolant in the core will just sit and therefore and most likely eventually rot it out - so open them up from time to time to circulate the coolant. Newer extended life coolants are less corrosive and need fewer changes over the years - but it never hurts to do a flush at least every couple years to keep the system clean. Dispose of drained coolant in the proper manner as well and not tossing it out in a drain or in the yard behind the garage.

 

[b4thundr]

yup! is super easy to change! just do it! bolts are on the engine side of the firewall. seriously its easy, i got one from NAPA and it fit's great in the heater box. drop the glove box outta there too just to give ya more looking room to see the cables. EASY!

 

[renovate7]

I replaced the heater core. Took about 2 hours. I could do it now in 1 hour. Removed the glove box and back battery. Took 20 minutes of TUGGING and prying to realize there was a bolt behind the fuel filter. Can't believe all the different bolt sizes from 10mm on the lag screw on the right side to the 9/32 hex heads on the cable screws, whatever happened to 1/4" or 5/16"?. Used a Spectrum brand from NAPA, $27.78 plus tax.

 

[b4thundr]

Yeah buddy nice!! I forgot about removing the back battery lol!

 

[edpdx]

Yup, I'm with Skinny. Do it now, your cold feet will thank you. I have a bit of a write up on my post about the HC R&R. It reads and sounds more difficult than it is. If you have an OEM core and it looks half-way decent. See if you can find a shop to refurb it. I don't know for the life of me how they do it, but I used a NAPA part and it was almost as sorry looking as the Chinese ones at Oreally and Auto Ztoners. My post shows where the "problematic" of the 3 bolts on the firewall are. And you will sail though this if you remove the rear batt and bracket, and get your 10mm sockets, extensions, u-joint and headlamp in place before you start. Don't wait. Do it now, I command you.