Mystery Coolant Leak

[Carzan]

My 80 has a pretty bad coolant leak but I can’t seem to figure out where it’s coming from. It is dripping right at the catalytic converter. Here is a picture of it

Do you guys have any idea where it could be coming from?

 

[80serie]

Check your rear heater hoses.

 

[Carzan]

Check your rear heater hoses.

I believe it is leaking from the hard lines that go over the cat. Are those the ones that go to the rear heaters?

 

[Carzan]

Check your rear heater hoses.

Here are some pictures of the lines I believe are leaking

 

[truthdetector]

Yes, those are the lines to the rear heater. Very common to rot away and not easy to replace. Search MUD for how to bypass the rear heater circuit.

 

[Godwin]

Rear heater delete kit

LCP - Rear Heater Delete Hose

Molded Rear Heater Delete Hose The upgraded installation with a perfectly molded hose.

sites.google.com

 

[Kernal]

If you plan to keep your rear heater IME the rear-most section of rear heater hard pipes and associated hoses can be removed without too much trouble. First remove the heat shields above the cats. IIRC there's just a few 10mm nuts holding them in place via short studs pointing down from the floor pan. Then more 10mm nuts holding the pipes to the floor pan. The hoses are not available separately from Toyota so get a good quality hose such as GATES GREEN STRIPE 1/2" ID (not White Stripe or any cheapo hose unless you want to do it again).

It's the first section of the rear heater pipes that are about impossible to replace without removing the transmission. IIRC on person (?OGBeno) did it by
first separating the two pipes and feeding one pipe at a time up from below. Others have replaced the hard lines with heavy duty heater hose ie: GATES GREEN STRIPE along with some protective sleeves where needed.

Tip/Warning: if you plan to keep your rear heater do NOT tug on the hoses that go up to the floor pan (post #4, top photo) as those are connected directly to the (soft) brass pipes that are part of the heater core, they WILL bend if you abuse them. You need to carefully slice the hoses lengthwise at the end using a hobby knife (like a surgeons pointed scalpel) at the ends in a few places, then carefully peel the slices away from the pipes until it all comes off.

 

[Marvelicious]

Bit of a sidetrack, but has anyone ever considered replacing a failed rear heater with one of those little PTC ceramic heater modules? You've got a 20amp circuit available if you ditch the factory fan... maybe a pair of 100watt modules running 1 on low, both on high. I suspect it wouldn't match the standard heater for output, but the heater lines wouldn't be a problem, and you'd have some instant heat available to take the chill off while you're waiting for the engine to warm up. Just kicking an idea around, my OEM rear heater is still going strong.