Reconfiguring and simplifying heater hose assembly. Will it work?

[donemilio21]

I am replacing all the heater hoses and the control valve. Toyota has this weirdly shaped brass tube that acts as a t-fitting and 3 piece assembly of two rubber hoses and a U-shaped metal tube connecting to the control valve. Could I replaced the long metal tube (marked blue on the pictures) with a stainless steel or aluminum T-Connector and the 3-piece assembly (marked red on the pictures) with a longer 5/8 heater hose ? I believe this is the set-up in 100 series. Has anyone done this?

 

[MurderBird45]

Search for Rear Heater Delete. There’s an in depth how to that will get you pointed in the right direction.

 

[Kernal]

On the pipe assembly with two outlets pointing toward the firewall (marked in blue in your photo): the top pipe is 5/8" for the main heater core and the lower pipe is 1/2" for the rear heater pipe you can see in the photo bolted to the firewall.

On the left side of your photo in the background you can see a T connector, same situation, the lower pipe and hose going to the rear heater pipe on the firewall are 1/2". Everything else is 5/8".

Question: what's your goal in replacing the brass pipe? It likely isn't leaking itself and will clean up once you pull the hoses off. The hoses however all appear to be leaking and all need to be replaced.

 

[donemilio21]

On the pipe assembly with two outlets pointing toward the firewall (marked in blue in your photo): the top pipe is 5/8" for the main heater core and the lower pipe is 1/2" for the rear heater pipe you can see in the photo bolted to the firewall.

On the left side of your photo in the background you can see a T connector, same situation, the lower pipe and hose going to the rear heater pipe on the firewall are 1/2". Everything else is 5/8".

Question: what's your goal in replacing the brass pipe? It likely isn't leaking itself and will clean up once you pull the hoses off. The hoses however all appear to be leaking and all need to be replaced.

Yes, I'm going to replace all the hoses. I cleaned the brass pipes as much as I could, there was a lot of corrosion in them, and lots of flakes came out when I brushed them. My goal is to replace them with something sturdier for half the cost and not re-use the ones I pulled out. Like this item. which has two 5/8" connections and one 1/2" connection, similar to the T connector you pointed out, which I'm also replacing.

 

[Pascoscout]

I'd think as long as everything fits and connects with no leaks you could run any configuration you want. Just remember that metal U is there to prevent the hose from getting kinked. When cold those hoses will bend fine but as they warm up the tight bends can fold over and block the flow. You might go back to the heater hose area in your local parts store and see if you can find a rubber section already formed to a U shape.

You're also adding more connection points by using 2 tees with (I assume) a short hose connecting them. More connections means more chances for leaks.

 

[Kernal]

The OEM replacement T connector for the passenger side is plastic if bought separately from Toyota. If you purchase the complete assembly (hose-T-hose) on that side it comes with a brass T and the hoses attached with the sardine can clamps.

 

[NLXTACY]

80 Series 1FZ Rear Heater Delete Hose

80 Series 1FZ Rear Heater Delete Hose (RHD-1)

absolute-wits-end.com

Although inbound from Japan.

 

[Irish Reiver]

@donemilio21 Just to clarify, are you looking to delete the rear heater or are you just trying to come up with a solution to replace existing brass pipe without having to buy one from Mr. T?

 

[donemilio21]

@donemilio21 Just to clarify, are you looking to delete the rear heater or are you just trying to come up with a solution to replace existing brass pipe without having to buy one from Mr. T?

Not trying to do a delete, just want to replace the brass pipes (the U and the long 3-way piece) with one aluminum T-connector and a longer hose. If I'm not mistaken Toyota went that way with the 100 series.

 

[donemilio21]

I'd think as long as everything fits and connects with no leaks you could run any configuration you want. Just remember that metal U is there to prevent the hose from getting kinked. When cold those hoses will bend fine but as they warm up the tight bends can fold over and block the flow. You might go back to the heater hose area in your local parts store and see if you can find a rubber section already formed to a U shape.

You're also adding more connection points by using 2 tees with (I assume) a short hose connecting them. More connections means more chances for leaks.

That is a good point. That's the type of feedback I was looking for. There must have been a reason they built that assembly with that many pieces.

Actually my setup would eliminate two connection points since the proposal is to replace the 3 red dotted pieces on the picture with just one hose.

 

[OffRoadScott]

I just replaced my heater and front heater hoses, actually deleted the rear while at it. I used a Gates hose with a formed 90 degree and used a straight Gates hose for the right side of the head.