A70 Heater Core (?) Leak

[Endless]

Got a bit of a problem with the old JZA70, not sure if all A70's have the same heater core arrangement or not but just thought i'd specify what i've got.

I was mucking around with the pipes when i was removing turbos and the top drivers side heater hose has developed a leak, at first i thought it was just the clamp as it was leaking in the engine bay down the firewall so i re-checked that and it seemed to of fixed it.

Anyway the other night started the car and let it run for a bit, once it warmed up i then noticed in the cabin there was a leak coming down drivers side from where the pipe comes into the car through firewall and i presume then goes into the heater core.
Looked like a copper pipe and the leak is coming from between the firewall to the other side where the leaking pipe i mentioned is.

Any ideas on how to fix, what i've done etc...hoping i havent snapped welds or something as i keep hearing nasty stories about taking whole dash apart to replace the core, surely toyota didn't put a weld in between cabin and firewall?

[kingmick]

If the firewall grommet isnt a tight one it maybe just the pipe you moved weeping.
If there is a bit of slack in the hose, cut a piece of the end and then clean the copper pipe properly and hose clamp it back on.
If that dosnt work it might be a copper joint inside.

[Smokey228]

Those welds seen to rust and break, but that usualy follows a build up of crap on the ends that ruins the seal... So it could be a broken weld on the heater box, but more likely rust and crap built up under your hose clamp...

Jase

[Endless]

Yeah i was thinking/hoping i might of popped it back through the grommet... i'll have a looksee on the weekend.

Cheers for help guys.

[cressida_1jz]

If you sort of yanked at the pipe,id say its come off the heaters tanks were the pipe is actually soldered.

there pretty piss weak.Ive repaired heaps at work,and a **** of a job to pull out aswell

[cressida_1jz]

And also,get the heater recored while its out.

Saves you pulling the bastard out again coz ive done alot of 90-95s model toyotas this winter.

[Mos]

If memory serves me correctly there's a joint on top of the heater assembly with most likely an O-ring sealing it. If you disturbed that in the wrong way it could be the culprit. I think I've given away all the *A70 heater assemblies so can't take any photos for you... But there's at least one person currently doing an engine swap out of a JZA70 half cut - you could ask him for some photos to give you ideas of what may have happened.
In any case it will be a pain if you need to pull it out...

Mos.

[wiso]

i can tell you all A70's have the same heater core setup, my ma70 is the same as the jza70.

did you have to lever at the pipe to get it off? you may have deformed the shape of the pipe, i did this, it wasn't totaly round not quite but it weeped a little, i just ran a 10mm socket around inside it to round it up again.

[Xistant]

i can tell you all A70's have the same heater core setup, my ma70 is the same as the jza70.

I 2nd That motion!!!!! there all the same across the a70, although i will never, ever, EVER! take one apart again.

[Endless]

I don't think i gave the pipe much of a hurting at all really, wasn't using enough force to deform it i would think.
All i did was reconnect the hose on there and just push it on firmly after i noticed it was leaking and put the clamp a bit further down the hose, didn't really notice much movement of the pipe but i suppose this could have disturbed it...

The leak definately is coming from where the pipe comes/goes through the firewall, which makes me think (have some hope) it's not the actual core hmmm..

Anyone got a pic of an A70 heater core to hand?

[wiso]

just went and snapped my spare for ya, see what i mean about deforming hehe, there was abit of force and levering to get that off.

if the coolant was actually coming intot he car it could be the core or those joins in the pipes, just o-rings inside. but if it only int he engine bay it would be the rubber pipes

[Endless]

Wiso thanks, really appreciate that mate... i'll give ya more rep when i'm allowed to!

I wonder if i've popped that ring on the far side pipe through the grommet, causing it to leak inside as it's leaking both in engine bay and inside cabin.

Damn that pic really helps.. thanks again!

[wiso]

another pic of the ring



i think it would be hard to pop the ring off if you didn't actually remove it yourself

[Endless]

Sorry was refering to this bit i've circled, perhaps i've pushed it back through the grommet on the firewall causing the leak to be inside the car.