Mystery leak, not PHH

[nodaksn3]

A couple of days ago I noticed the coolent level slowly going down in the resevoir tank. Today I noticed a pretty significant deip from the left side of the engine. The PHH came to mind, although I've replaced it twice. After checking it isn't the PHH. I suspect what the FSM calls either the No.1 or No. 2 by pass hose. Problem is: I can't find either one. Can anybody help? Do I have to dismantle anything to get to them? Thanks, Ned

 

[cruiserdan]

The #1 bypass hose from the back of the head up to the rear of the throttle body is ~1/2 inch OD and originates at the head a couple inches in front of the PHH bib.

 

[george_tlc]

Bloody 1fz has way too many stupid little hoses going hither and yon. Toyota mech that designed the cooling system must have had a brother in the hose business.

Anyhow, given the age of our 80's, one should really consider replacing ALL the hoses (not just coolant) and checking the condition of all clamps and replacing those too as needed.

I had the #1 bypass weeping where it connects to the extension barb that goes to the s/c. Rubber rot at the end where the clamp was. Cut it back 1/2" and re-clamped and all has been good for a few months and no more coolant bottle refills required. At least with the Toyota red coolant it becomes easy to see where a leak/weep is due to the buildup of the red/pink crust as the coolant dries after each cycle. I need to replace that hose section soon.

Oh the simplicity of my old patrol in oz: 2 radiator hoses, 1 u-shaped thermostat/waterpump bypass hose and 2 heater hoses and all can be reached EASILY!

cheers,
george.

 

[heavyduty]

My LX sprung a coolant leak in the vicinity of the PHH this morning, less than 100km after doing the head gasket. I removed the FDS wheel and the small mud guard to get a better look. It was leaking at the #1 bypass hose clamp at the head nipple. A quick search on Mud led me to this thread and George's fix. I cut about 1/2 inch off the hose, which clearly showed holes worn through the hose by the clamp. There was enough length in the hose to re-attach and clamp. Leak stopped.

While doing the head gasket, I replaced the PPH and a few others, but not this particular hose. If you are doing your head gasket, I suggest adding this hose to your 'while I am in there' list.