L series heater - no heat

fredsub · Post by **fredsub** » Tue Jun 27, 2006 12:07 am

trying to figure out why there is no heat at all from the cabin heater. I idled the motor long enough (the fans switched on) - no heat, feelin the hoses to the cabin heater core are hotish.
The cable that goes from the heater control down to the heater to control the flap - well somehow it had slipped off the peg thingy - fixed that, but still its the same - no heat.
whats going on here ? it did used to heat - in fact it didn't have a cool position once a upon a time...........since when the core was replaced maybe 2yrs ago.
Also i'm sure the fan did use to push more air once upon a time...........

surely its the flap thing that controls whether air passes through the core or not......

is there a flap at the top end of the heater assembly also? i can't recall

hmmm, i'v been just looking at the gregorys..the pic has a lever there, on the bottom side...i don't recall how that works...should've done pics when i had it all apart years ago

subanator · Post by **subanator** » Tue Jun 27, 2006 12:36 am

Fred, just ripped out the core from a spare today and noted....
Noticed that on top of it a large flap (Top of core LHS) actuated via the bevel gear from behind,
Another on the RHS is operated inside the little protector cover.
Top of box are a couple of vent flaps.

Note that they are all vacuum bellow actuated via the button control bank, so if you are having a problem opening them, I would be checking all the vac lines etc.

fredsub · Post by **fredsub** » Tue Jun 27, 2006 8:28 am

thanks, i guess the top flap must be to allow air to the under window vents.......
I tested the vacuum/motors and appear to somewhat work.......

I wonder, the bottom flap, is it something that could possible break from its lever, such that it doesn't flap no more ? how robust is that ? the cable controlling that lever does seem to move a little too easily....

damn pullling out the dash to solve this is not what I want

subanator · Post by **subanator** » Tue Jun 27, 2006 10:39 pm

Its a tough call mate to just pull that mongrel out just for the damn flap.
If its possible to get access to the RHS of the heater box via the footwell, you may just be able to reach around to check linkages. (or jack it open)

The rear bevel gear lever to the flap is just plastic, it has to be prised off to get the core out. If you have done this before?? it may have come loose or split? Doesnt seem to have any real tension on it to break.

The little plastic cover on the RHS will come off easy, as it clips in. This give acces to the other lower lever.

I recall the cable you mention, cant remember, but it looped to some upper lever?? Was a few months back now.

Smokey · Post by **Smokey** » Wed Jun 28, 2006 9:54 pm

Hey Fred,

I have my dash out and a replacement whole box assemblyin the garage. I am not familiar with it at all yet as I have not fitted the replacement yet. Still welding and grinding.

I can take pics and have a look if you ask specific questions. Let me know if I can help.

Smokey

fredsub · Post by **fredsub** » Fri Jun 30, 2006 12:06 am

I will have to pull the dash, but just need to decide whether I should be prepared with a replacement flap or whatever beforehand. A pic on the section inside there might help, not sure what mode of breakage is possible there either, so thanks Smokey if ya can do that

subanator · Post by **subanator** » Sat Jul 01, 2006 12:25 am

I have a spare box pulled apart right now, will post pics this w/e.

subanator · Post by **subanator** » Sun Jul 02, 2006 11:46 pm

Fred-sub, I havent forgotten, just was too busy getting mine of the stands with CV boots changed and another little job.
Got tomorrow off, will get a pic for you.

fredsub · Post by **fredsub** » Mon Jul 03, 2006 8:31 am

thanks mate, don't stress yourself :P

subanator · Post by **subanator** » Mon Jul 03, 2006 11:48 pm

Ok, got it. Had a little drama charging the camera, got there in the end.

This pic - general RHS view, separated in half to open

This second pic is from the rear that is up against the firewall.
Note cable operates flaps via bevel and linkage. The hot side flap (RHS, or photo left) is metal and on a direct pivot. From the connecting linkage to a plastic lever on a plastic cold side flap.

The last pic is inside of the rear half (inside of above pic), showing the flaps and heater core

Hope this helps,
Cheers Roger

fredsub · Post by **fredsub** » Tue Jul 04, 2006 8:56 am

Thanks :P

looking at that, it may simply be that hot side flap pivot gear might be disjointed, and the 2 screws might be the only thing holding the cover on that side...so I should be able to get at it in-situ :P

still have to be a practising contortionist - hows on your back over the door sill, head up under the dash

subanator · Post by **subanator** » Tue Jul 04, 2006 11:42 pm

Cover should be real easy to get off. See middle pic, lower RHS corner is actually the cover that is over the bevel gear - should just flick off left to right.

A retaining screw holds the hot flap pivot in situ.

That contortionist position......brings back bad memories from days working on a Holden wiring fault....LOL

Funky1 · Post by **Funky1** » Mon Aug 07, 2006 2:37 am

Guys, great details and pics.

On a heater-related issue, I just bought a '91 L Series wagon which had the coolant input/output to the heater bypassed and therefore the heater/de-mister function does not work. On reconnecting the heater and turning on the windscreen de-mister, the de-mister blows moist warm air onto the windscreen, causing it to fog up badly. Obviously there is a coolant leak in the heater.

My questions are:
1. is this a common problem
2. is it easily repairable or do I need to source a replacement heater unit?
3. if I do source another heater, how hard is it to install?

Thanks in advance.

MUDRAT · Post by **MUDRAT** » Mon Aug 07, 2006 3:56 am

1: Yes, leaking heater cores are fairly common

2: Try a can of ChemiWeld from your local Repco/generic parts store. If this doesn't work my advice would be to get a new heater core. I think most radiator specialists can get them in - a preferable option to getting one from a wreck.

3: Not hard, just painful. You'll need to remove the whole dashboard, budget one whole day for this job. Your Gregories will guide you through the process easily.

Funky1 · Post by **Funky1** » Mon Aug 07, 2006 9:27 am

Thanks for the quick reply.

I prefer the Chemiweld option over the all-day (skinned knuckles and cricked-neck) option.

Will let you know how it goes.

fredsub · Post by **fredsub** » Mon Aug 07, 2006 10:30 am

MUDRAT wrote: 2: Try a can of ChemiWeld from your local Repco/generic parts store. If this doesn't work my advice would be to get a new heater core. I think most radiator specialists can get them in - a preferable option to getting one from a wreck.

can't believe your recommending that to fix a heater core...the chances of it
stuffing the engine if it needs fixing is a risky side effect.
Got a can of the stuff, never been game to use it....anyone want it?

Funky1 wrote: I prefer the Chemiweld option over the all-day (skinned knuckles and cricked-neck) option.

Funky1, sorry to be a bit adverse..pull yer finger out, get some skinned knuckle and replace the heater core, the OEM one is shit anyway, with their plastic end tanks.

MUDRAT · Post by **MUDRAT** » Mon Aug 07, 2006 1:00 pm

fredsub wrote:can't believe your recommending that to fix a heater core...

Well it works, that's all I can say. Someone in my Mercedes club put it into a $120,000 Mercedes Benz before with excellent results.

Funky1 · Post by **Funky1** » Wed Aug 09, 2006 2:29 pm

Went and checked out some cooling system repair products and read the back of the Chemiweld bottle. That's some serious s**t! Said it was for cracked blocks and such. So I bought a bottle of the Nulon Radiator Repair as it was the only product that actually mentioned it could repair heater cores. Only really need it to get the heater and windscreen demister working so it would pass rego (they pinged me for that of all things!!!)

If I end up keeping the wagon for the long term, I'll look at the harder job then.