What the heck is that leak?

Hey folks,

Super stoked to have bought my Turbodiesel 1998 AWD Hiace camper last year, & have been having a blast with it ever since. Love this forum!

When I bought it there was some rust damage at the bottom of a panel junction just behind the driver side front wheel well. I had the dealer repair it without giving much thought to the source of the rust...until now.

There is a liquid stain on the panels again right where the rust repair was. I've been looking through the schematics in the repair manuals and can't find anything about that specific area. There is an air intake higher up that seems like an unlikely suspect - I've posted some pix of the liquid stain on the panel and the underside of the van in that area with the hopes that someone might have seen this before and can point me in the right direction.

Cheers & thanks to all!

That is a closed of area that only features the air intake and filter, which doesnt involve any liquid. However, there is a lid to this space on top, behind your chair. You need to unbolt it, probably under the carpet. Check if carpet is dry.
The sliding door cannot open on that side? Do you see anything on the inside?

Anyway, above this air filter space there is a narrow space/ pillar that goes to the roof. A roof leakage might end up there below?
It is the pillar where your seatbelt is fixed to.
But this is just a theory.

Thanks for the tip, I checked that area before posting including the carpet and unbolted the lid. Also checked the interior access panel for the air filter. No liquids or evidence of leaks. The sealed metal box area is not accessed from the lid behind the drivers seat which ends at the 1st panel junction, it seems to be under the floor. I might have to pry up the vinyl flooring to take a look to see if there is another access panel there.

I thought of roof leakage as well and logically it would seem that the 'metal box' is where the liquid would end up but there do not seem to be any perforations or other sources where water might ingress.

Another theory could be condensation running down into the support pillar from the secondary AC unit that cools the rear cabin. But again, I did not see any evidence of moisture when looking in the pillar access panel. Putting my CSI hat on for this one.

Yes it is hard. I have a LHD one, so I have a sliding door there. But that doesn't give me any extra info.
It would be good to see where the AC condensation is going, because it needs a path to go to.

Also, if you don't find the cause, I would drill a hole, just to let it out at least, so there is no build up.

If you remove the drivers seat you can unbolt the air filter inspection panel and have a look at that from the top.
Good luck!

Thanks! Did that by sliding the drivers seat all the way forward & could access the panel - all is dry and looking normal down there.
Cheers

Ah.!

The inside of the inner sill has a series of little bungs in it, that can be popped out for inspection, perhaps with a $5 endoscope: maybe worth a look, it must arrive from somewhere .

Check the rain is simply not getting in the air intake too, I can't recall what that looks like but it's a thought!

GPW wrote:

Ah.!

The inside of the inner sill has a series of little bungs in it, that can be popped out for inspection, perhaps with a $5 endoscope: maybe worth a look, it must arrive from somewhere .

Check the rain is simply not getting in the air intake too, I can't recall what that looks like but it's a thought!

For water to enter in the air intake it would go two possible ways, which should not lead to this result.
First way is to end up in the water catching reservoir which you can drain (the white one on the pictures), a Hiace can actually take a few sips of water before it reaches the engine.
Second way is if it would pass through the rubbers, not going into the air intake. Then it should just get down out of the car, since the air intake space is open.


I am still very curious how that second AC unit condensation is drained. In the parts system I see 2 lines, on right and left side of car, go straight down but no clue to where. Which means they probably go through the pillar where the seatbelt is connected to. Maybe there is something wrong with it. I don't have AC so I don't know how these lines go.

You could follow these drainage lines, or use the AC when inspecting this pillar or other hidden spaces.
Perhaps boil some water in the van to get all the humidity in the van and run the A/C. See where it leaves some spots on the ground.
Or, find the beginning of those drainage tubes, disconnect them from AC unit and put some water in there, to see if it comes out.
Since they should be there on left and right, it could be that left is going to the ground and right has an issue.
If any of this has to do with the AC, it could be something else completely.

Hiace4wd wrote:

I have a LHD one, so I have a sliding door there.

Wait, what?? You have a LHD Super Custom? I didn’t know they existed. Where was it manufactured/assembled?

Some where in that vicinity you should have drainage pipes from saloon a/c and if you have sunroof... from them as well. If those hoses were cut off or in any other way were restricted, then you might be looking at results.

You might want to get a buddy slowly hose your sun roofs while you are watching for any evidence of moisture... If that is in correlation, then you need to trace down those drainage hoses (they are from clear plastic about 15-20mm in diameter) and for that yo will need to take the interior a part a bit...

Pete_nz wrote:

Hiace4wd wrote:

I have a LHD one, so I have a sliding door there.

Wait, what?? You have a LHD Super Custom? I didn’t know they existed. Where was it manufactured/assembled?

First of all, I don't have a super custom
All the LHD versions are worker vans, like base models. I don't even have power windows.
They also never come with the 1KZ, just with slower diesels 2L and 3L. But with manual and low gearing 4x4 so very capable.

Also just produced in Japan like all of them.

What is interesting is that the Chinese company Jinbei has bought the designs, and so new vans are still made in China with LHD. Don't know if they are still being made, but for a long time they were.
And those aren't super custom versions as well.

Thanks to all for the great input & ideas, I think that I will start with checking to see if there is some water ingress from the drainage of the saloon AC & will report back.

Might take a few days - the Hiace is my daily driver and with two small kiddos I have to reassemble each time the family needs to run to town for something.

I would have thought that someone else might have come across this same type of moisture stain but alas it seems that this might be a unique case. Cheers

It's been a while and I still haven't tracked down the interior ingress point for liquid working it's way into the panel, well...that is until I looked at the van today after a rainfall.



I could be wrong here, but it sort of looks like the graphics on the van are sending the rain runoff from the side window right into the joint of the two panels. Very odd indeed.

Has anyone else ever seen water ingress from external sources (ex rain) though the panel joints before?

This is a head scratcher

Ha, this might indeed be the graphics.
These are probably the sliding windows, that have a hole there on the right (and left) for water to run off.
I would put some tape over it to see if it runs down via the tape, and the original spot stays dry or dryer at least.

Finally getting around to updating this post, apologies for the delay to everyone who commented with helpful tips last Fall.

As it turns out, one of the possibilities discussed above was that the rust/discoloration spot was coming from the drain for the condenser of the secondary passenger AC unit in our high roof van which sits between the driver cabin and rear cabin.

There is a black rubber drain tube that runs down on each side of the van inside the side pillars. The drain on the driver side, where the discoloration is, seems noticeably shorter and does not extend beneath the frame.

It is quite possible that runoff from the condensation during hot months is the source of this issue but seeing that it is winter in the mountains of British Columbia I won't know for sure for a few months. In the meantime I will extend the 'short' drain tube with an extension.

Thanks again to all, I will update again in the hotter months once the theory has been tested.