Rear Heat Bypass

[jmvar]

I want to do the rear heat bypass and had read up on it in the thread Beno refers to here:

https://forum.ih8mud.com/showthread.php?t=129271&highlight=rear+heat

Looks like the thread was deleted. Anyone know what size heater hoses I need to do the bypass? I think I need 2 different sizes.

I looked for Gates green stripe at my local Napa but they didn't have it and they said they don't sell it any more. When I asked the clerk what the difference was between the white stripe they did have and the green stripe I wanted he had no clue and was unwilling to find an answer. Does it perform just as well?

TIA

 

[IBCRUSN]

5/8" heater hose does the trick. I wouldn't worry too much about Green Stripe or White just decent stuff and it will likely last another 100k.

Here are a couple pics.

 

[jmvar]

IBCRUSN, thanks for the pics, the original post I was refering to was actually yours.

Rear heater bypass was a success. My lines were looking pretty ugly and I didn't even want to deal with them.

Couple of tips:
-In IBCRUSN's second pic there is what looks to be like a vacuum actuator of some sort with a blue top, not sure what it is. Remove that with it's bracket making sure to keep track of all vacuum lines and their initial positions. This will give you more room to manuever and get your hands on the heater hoses.

-once you have disconnected the lines from the main circuit of heater hoses, it may be difficult to get channel locks on the clamps that are holding the old T connections to the hard lines that go the rear heater core. Bend the fakers towards the front of the truck to give yourself more room to get those clamps off.

-Leave some heater hose on one of the hard lines that goes to the rear heater core so that you can seal up a noozle to blow compressed air into the now open lines. This will get alot of the coolant out of the lines, will probably not get all of it. Be carefull not to get a face full of coolant. I put the pan you take of to drain the radiator in place so the coolant wouldn't spray in my face.

-Be carefull with the inlet and outlet nipples coming out of the firewall, you don't want to mess these up trying to take the hoses off of them. You can be a gorrilla with the hard lines that go to the rear heater though....

 

[djsherif]

5/8" heater hose does the trick. I wouldn't worry too much about Green Stripe or White just decent stuff and it will likely last another 100k.

Here are a couple pics.

Sorry to revive such an old thread but i have questions about the 2nd pic. Is that cable attached to the lever supposed to move when i move the temperature slider in the cab? Or when should it move?

I'm having problems getting good heat from front vents but rear heater works perfectly.

Thanks in advance.

 

[96r50]

It should move as that is the heater valve which controls the amount of hot coolant flowing to the front and rear heaters. I think the set up on the diesels is backwards from the gassers though (gasser: hot=cable puled in, cold=cable pushed out). However, if you are getting rear heat but no front heat I'd say that the blend door in the front heater might be out of whack, or the front heater core might be clogged (less likely I would think).

 

[djsherif]

Thanks Adam. Yes it's reversed on my diesel. I adjusted the valve to a different position to a lower position and I'm getting much more heat now but the cable itself doesn't move when I slide the internal temp control. Do these cables usually seize up, maybe just needs some grease or could it have snapped or come loose behind the hvac unit in the dash?

 

[96r50]

Unfortunately, I think all three solutions are possible. I'd start by trying to dribble some type of pentrating fluid down into the cable if it looks gunked up. It may have come loose behind the dash, or the little servomotor that moves the cable may have burnt up. It's going to take some diagnostic work to figure it out. Do you have an FSM? I can send you the relevant pages from my 96 USDM manual if you PM me your email.

 

[djsherif]

I have one thanks, just wasn't sure where to start looking. I'll try and find the relevant pages. This easily fixable, replaceable you think?

 

[p8nt]

Old thread revival:

Is there a way, other than a dremel, that Im supposed to work with the original hose clamps? The ones that look like they have a cotter pin in them. I cant see a way around cutting them off.

 

[FirstToy]

If I remember right, you twist the cotter pin to "unscrew" and release tension on the band. Then you pull out the pin (or cut).

I think I ended up loosening and just cutting the band w/ some snips.

 

[cool breeze]

Since the topic popped up...i did exactly the opposite of being careful with the hardline coming out the firewall and mangled it with soime pliers. I managed to get it round enough with a 1/2in adapter, or squarish, for the hose to fit over. Its been working for about a year now but it still bothers me.

Is there a method to get the copper pipe back to round?

 

[p8nt]

You guys have any tricks for removing the stuck heater hose? The driver side firewall is giving me fits.

 

[womacje]

Rear blower hole cover

I have just bypassed the rear heater and removed all the lines... That sucked. The rear blower doesn't need to live under my seat, so

-how have y'all filled the 2"+/- size hole left. Curious to see your ingenuity.

 

[Brunt Force Trauma]

I have just bypassed the rear heater and removed all the lines... That sucked. The rear blower doesn't need to live under my seat, so

-how have y'all filled the 2"+/- size hole left. Curious to see your ingenuity.

I Welded a piece of Sheet.

 

[womacje]

I Welded a piece of Sheet.

That seems so committal! But that's probably the cleanest way.

I thought about using rtv and sandwiching the whole between 2 sheets of metal.

Thanks,

Jeremy

 

[ppc]

That seems so committal! But that's probably the cleanest way.

I thought about using rtv and sandwiching the whole between 2 sheets of metal.

Thanks,

Jeremy

I would only use one piece of metal. With two, the potential to trap water between and create rust is much greater. Use one layer and paint both sides.

 

[cool breeze]

Used a piece of galvanized metal and some JB weld, 2 years running.

 

[womacje]

Used a piece of galvanized metal and some JB weld, 2 years running.

I blasted 4 holes thru an rtv'd it.

 

[notthejeepnomo]

djsherif: did you figure out how to fix the heater valve?
mine also whacked out when i bypassed the rear heater.

 

[womacje]

djsherif: did you figure out how to fix the heater valve?
mine also whacked out when i bypassed the rear heater.

I'd e more than happy to sell you my rear heater. Worked fine before I took it out.