Bypassing heater core valve in Mexico? (1 Viewer)

[Black94Prado]

Hey guys. I am currently in Mexico, about 3 and a half months into the pan-american road trip from Canada south. I recently got a pretty substantial coolant leak coming from the heater core valve and t-fittings. Upon further investigation the t-fitting split for the heater hose and the heater core valve were cracked and trying to gently pry the hose off broke both fittings. The plastic is so brittle it just crumbles in my fingers. I was able to find some 5/8 heater hose and a 3 way 5/8 t-fitting but now I'm realizing one of the 3 sides of the fitting isn't 5/8 but smaller.

Thing is I don't need the heater core valve so I'm just trying to bypass it, but I'm not sure if I can plug any of the hoses or not. I put some pictures of the split and just need some help here... I'm in a small town on the pacific coast and finding these specific sized t-fittings is impossible it seems. If I can get away plugging some of these that would help. Truck is a kzj78 with a 1kzte. (Prado).

 

[Felde]

The heater valve is supposed to sit on the bracket in your 1st pic. It's operated by a wire from the leaver in the dash.
A hose comes from the engine block and feeds into it...
When the heater is off, this valve is totally shut anyway. So there is no issue in taking the feeding hose off and block it (engine side).
The heater outlet feeds back into the cooling circuit (waterpump suction side). How exactly that pipe is routed depends on the engine type.
That one also needs to be blocked (engine side); best directly next to the heater core outlet.
Just make sure you put decent fitting plugs and clamp those really good, as the hoses have full pressure of the cooling system.
The inlet and the outlet of the heater core may be blocked with just anything or even left open. In worst case some rest fluid may seep out when the truck sits at an angle.
Good Luck, Ralf

 

[Black94Prado]

The heater valve is supposed to sit on the bracket in your 1st pic. It's operated by a wire from the leaver in the dash.
A hose comes from the engine block and feeds into it...
When the heater is off, this valve is totally shut anyway. So there is no issue in taking the feeding hose off and block it (engine side).
The heater outlet feeds back into the cooling circuit (waterpump suction side). How exactly that pipe is routed depends on the engine type.
That one also needs to be blocked (engine side); best directly next to the heater core outlet.
Just make sure you put decent fitting plugs and clamp those really good, as the hoses have full pressure of the cooling system.
The inlet and the outlet of the heater core may be blocked with just anything or even left open. In worst case some rest fluid may seep out when the truck sits at an angle.
Good Luck, Ralf

Hey yes I removed the heater core valve to have some more room to work. So after fighting with these old hoses for the better part of an hour or two I got all of them off. There's one 3/8 fitting that runs direct into the firewall and a 1/2 fitting (I think) that run down some piping under the truck and then plumbs into the floor panels about half way down the body of the truck. This prado has a rear passenger controlled heater so I am assuming that is what it's for? And then finally a 3/8 outlet that is from the engine side. Just to be clear, I can block all 3 off right?

 

[Felde]

The pictures show the heater core side (incl rear heater). Those are not really relevant.
Important are feed and return hoses engine side. Make sure you are clear on those.

And check your engine coolant level. You might also need to bleed the coolant circuit as taking off the hoses let air in.
BR Ralf

 

[Black94Prado]

The pictures show the heater core side (incl rear heater). Those are not really relevant.
Important are feed and return hoses engine side. Make sure you are clear on those.

And check your engine coolant level. You might also need to bleed the coolant circuit as taking off the hoses let air in.
BR Ralf

The engine return feed is in the bottom of the photo, there's 3 fittings in this pic.

But I think I've finally figured it out. So there's the feed and return hose but there's two t-fittings as well splitting the hoses to the front and rear heater. So the yellow x's are the front heater core input output, the orange x's are the rear heater core (passenger control). And I have to just connect the feed and return on the engine where the two green arrows point to. This will bypass the entire heater core system front and rear.

 

[Black94Prado]

Alright boom. Bypassed the front and rear heater cores. This should do. Now problem 2, finding a replacement key after getting wasted in mexico and losing my car keys.

Thanks for the help.

 

[janyyc]

Nice. Pro tip - always take a picture of your car key, and keep it stored in a secure file on your phone & laptop. Has saved me before...

 

[Black94Prado]

Nice. Pro tip - always take a picture of your car key, and keep it stored in a secure file on your phone & laptop. Has saved me before...

Ah yeah noted noted I will do that... Anyways a Mexican rasta man with dreadlocks floated my keys back to me at a reggae beach club last night. Strangest series of events ever.