Help - FJ60 Rear Heater hoses leaking under truck

[Spike Strip]

FWIW, when mine went, I played around with the idea of installing a pneumatic heater core valve or mechanical valve (generic on RockAuto) and modifying the plumbing to keep the rear heater, but being in So Cal, it wasn't worth it for me, or really needed.

The pneumatic valve would be a simple matter to control off engine vacuum, using a generic Vacuum switching valve, to control from the cabin so you wouldn't have to get out of the truck to operate. Of course, you'd have take the core to a good radiator shop and have them braze on some new tubing to delete/bypass the leaky valve. Probably would be easy to wire the Vac Control Valve into the rear heater blower switch so you control everything from that one switch.

 

[Boicruiserloser72]

the metal tubes are delicate
DO NOT USE WORM DRIVE CLAMPS
easy to overtighten and distort the tube

Ugh! I ordered OEM worm drive clamps from Toyota, exactly as they were installed from the factory. In trying to install 5/8" hose onto the metric steel tubes that run down the chassis, I discovered (before I damaged anything) the OEM worm drives kink instead of delivering uniform pressure around the hose. What works?

 

[S.CarolinaFZJ80]

I replaced the oe clamps with spring clamps as seen in post #7.
I forget the exact size. I got a kit of metric spring clamps that had multiple sizes and just used what fit

 

[Boicruiserloser72]

The FJ60 is operational again with a temporary, very simple (and I'll admit, ugly) bypass. I want to emphasis this is 1/2" heater hose, NOT 5/8" heater hose (I read that somewhere within the forum). 5/8" heater hose does not fit the OEM metric steel tubing on the frame or brass tubing of the rear heater core. Its way to big.
I have not application matched the Gates 18453 hose, but I suspect it is metric application as it is very close in inside diameter to the outside diameter of the steel and brass Toyota tubing. The steel tubing measured .55" (13.97 mm) OD, and the Gates 18453 molded hose measures roughly the same at .56" (14.22 mm) ID as pictured. The 1/2" heater hose slips firmly over the tubing with a little grease and the worm gear hose clamps worked perfectly.

Spike Strip, thanks for the ideas with the vacuum and mechanical valves above. It got me thinking of options and I am leaning on the 12 volt DC Vintage Air Servo Heater Control Valve. I think I could wire this into the fan switch for the rear heater and it would simply open the valve and turn on the fan simultaneously. The plumbing is going to be interesting... Looking forward to hearing from the radiator shop about the heater core soon, but happy to be back on the road for the weekend!

 

[Spike Strip]

This electronic heater valve is a Toyota OEM - It's used on newer Corollas. Should be easier to mount. You'd just need to figure out what pigtail it takes.

More Information for AISIN FSVT9005

 

[Boicruiserloser72]

This electronic heater valve is a Toyota OEM - It's used on newer Corollas. Should be easier to mount. You'd just need to figure out what pigtail it takes.

More Information for AISIN FSVT9005

View attachment 4013020

This is an excellent idea too. I landed on the Vintage Air valve because it included a pig tail. However, this could lead to some dumpster diving at the local salvage yards which could be a hours of fun!

 

[The Machinist]

Sounds like you have a solid plan, but if you need another rear heater core let me know. I just removed mine to install some new seats. I'm just across the valley from you.

 

[Boicruiserloser72]

Sounds like you have a solid plan, but if you need another rear heater core let me know. I just removed mine to install some new seats. I'm just across the valley from you.

Thank you for the offer! I happen to have picked up a second heater here in Boise last week from a Boise owner who is deleting his heater too for his restomod FJ60 project. It also shows signs of leaking. I left both cores with Mac's Radiator to test and /or modify. I'll keep yours in mind.

 

[CruiserTrash]

This is good stuff, mine is dripping under the truck on occasion too. I wonder what is doing the sealing inside the stock valve. Rubber o-ring maybe? I also wonder if the valve for the front heater - which is still available from Toyota - can be adapted. Maybe cut parts of it out and braze it into the existing tubing inside the rear heater?