Airbox drain hole access?

[oldskater]

After seeing numerous rotten Airboxes prior to getting my new late Square I am paranoid about the build up/blockage of the drain tubes.

So Question.... is it possible to get at and clean these drain holes/tubes?

I have a few piccies taken from a vehicle I saw that had a removable (read rotten) bulkhead... I could post them. They are very interesting and show how this area is built (and how it rots).

The problem is that the air vents on the outside let in water and dirt... The dirt blocks the internal drain holes and rust sets in. It appears to me that you can't get at these drain holes.

I was even wondering if its worth creating 2 large access holes in the airbox bulkhead (inside the front boot)... Obviously you would then fit rubber seals... anyone done anything like this?

Thanks

Julian

[purplepeter]

The easy way to get at them is whip the fuel tank out,and theyre just under the lip it sits in...otherwise you might manage it if youre a contortionist with very long arms!!

personally,i make sure i chuck a bucket of clean water down it,and that it continues to drain freely.

I keep meaning to ask Dave if its possible to just disconnect them from inside the car,& replace??

[nidge]

mine where blocked when i got the square. I managed to unblock them with a combination of a long screwdriver a hosepipe and compressed air from a blowgun.

[blistered]

Do you mean the ones for the front vents?

Don't know if it's different on a later car but on our 64 it's just rubber hose that you can get to relatively easily if you remove the black/grey cover thing behind where the radio would sit. We had to repair one of the hoses on ours cos it was split.

[nidge]

[quote="blistered"]Do you mean the ones for the front vents?

quote]

yes.

I didn't want to pull mine about in case they split. A bit of gentle proding and some water and air pressure ad they were soon running free

[oldskater]

Ok this may be of interest

Pics 1 and 2 were taken from a Square I went to see.

You can see what happens over time. BTW You can orientate yourself by looking at the brake fluid reservoir in pic 1 and comparing with pic 3

The arrow in pic 2 shows the rough path of the rain water... from the inlet at the top of the line shown, to the outlet pipe (not shown) at the arrow head

Pic 3 shows my car and you can see the air inlet vents... The worry is you cant see whats happening inside the bulkhead/airbox area! and I don't think you can even get at this area without cutting metal

[oldskater]

So to add

As far as I can see....

The only access is via *1 and the drain holes (I think there were 2) are roughly at *2 ...... So pretty difficult to get at



EDIT Sorry forgot Purplepeter said you could remove the tank .... Presumably to attack the tubes from the bottom ... i.e back flush them?

Not too happy about whipping the tank out...

Not even sure mine are blocked anyway (weekend test)

[purplepeter]

The drain tubes are literally half an inch under the top edge of the tank..see that tab of metal thats holding cables..theyr under that!

Taking the tank out just entails removing 4 bolts,undoing the 2 hose connections,and disconnecting the wire to the sender

Less than 5mins work

[DelBoy]

Here's a view of where the pipes exit under the fuel tank (from when my car was orange & rusty)


Under the dash this is where the plastic airbox mounts, and where the upper pipe connects to (you can see there is only one drain from here)
The airbox on my car had been previously patched, though you can see the drain tray had not been repaired properly. It's a swine to get to!


From the inside you can see where these pipes connect by the plastic airbox (now my car is shiny & green )


The airbox rusts out when dirt, leaves etc block the upper pipe and water sits just behind the panel you can see from the luggage compartment.

The only way this can be cleaned out properly is by taking out the airbox and digging out all the muck. It's worth flushing through the rubber pipes too. It's unlikely the blockage is in the area under the fuel tank, and you can see through this section easily without removing the tank, once the pipes are pulled off from the inside.

Hope the pictures help

[Editor]

There's only one drain hole in the metal tray, and it connects with the single hose down the right side of the airbox. The opening has a lip round it - that may also be rusted out and needs reforming to stop excess water sloshing down into the wirbox. Most UK Type 3s don't have a fan in there, so there's not much to be damaged by the water.

I used a hacksaw blade (as a padsaw) to cut the top off the box on my Fastback and mended the inside and the top, then tacked it back on and filled the thin gap.

[oldskater]

Wow..... chaps, what fantastic replies.... MANY THANKS

The airbox is comming out this weekend...

Those photos are fantastic.

Last night I did a test.... I poured a pint of H2O down the drivers side outside vent

Under the car 'most' of the water came out on the left hand side... (non on the right). However, unfortunately there was water ingress inside the car !!!!! not lots but too much for my liking.

It may have been the sheer volume of water that 'overcame' the airbox (thinking of it as a dam wall) .... A pint in about 1s is a major downpour.

Either way I am going to have a dig about and clean/investigate it


BTW .... sorry.... looks like this post should really be in The Workshop.

Julian

EDIT >>Under the car 'most' of the water came out on the left hand side...

Looking at the first pic, showing the outlet points, its unsurprising that the water came out on the left.... the car was sitting on a slight slope towards the left, so obviously the water would have gone that way...

[Editor]

No sooner said than done! Now in Workshop.

[oldskater]

Well ... what a job!!!!

cleared the hose but water still leaking in to the car, so the airbox needs to come out for investigation.

How on earth do you get it off.... I can feel the 4 10mm bolts but there is no way my socket will go over the nuts due to a cunningly placed set of ribs running the full length of the airbox on all 4 corners

Looks like it needs a deep/thin socket with a huge small dia extension bar

Anyone actually removed this without removing most of the dash underside?

Thanks chaps

Julian

[DelBoy]

You'll end up having to remove some stuff to get the airbox out - the air connections to the box, the dashboard support bar - and don't forget the air flap controls on the dashboard. It's not as big a job as it sounds!

You can reach the 4 bolts with a 12" extension, it's easier if you have a 1/4" drive socket that will reach.

[oldskater]

Well.... thought I would 'feed back'

Trip to Halfords for a 1/4" socket set and Bobs yer whatsit... the airbox came out (along with various bits of my skin)

Good job too.... The leak was actually comming from the tray/bulkhead seam (the area welded up in Delboys orange piccie above)

There is a bead that must have been designed to have some form of seal originally... I would be amazed if the guy who rebuilt my car sealed this so it was always going to leak.

Couple this with the fact that the detail design, by VW, is this area is incredibly poor - this area is always going to rust and its got nothing to do with keeping overflow pipes clear etc.... its just a really bad water trap with re-enterant corners!!!!

All I could do is silicone seal the seam from inside the car and I will water test later before reassembly

However, I have done a 'mod' which 'may' slow down the inevitable rust.
I have placed a small bore plastic tube inside the rust trap area and fed it up to the air inlet vents. I have then blanked it off (for normal driving). The tube is too small to block water flow.

The idea is that I can now inject water dispelling lubricant directly into the problem area.... WD40 should do it, or even a thin oil.

If I were rebuilding this area its crying out for a thin layer of silicone to act as a barrier ..... obviously not something available 40 years ago

IMO It could also do with a mod to put an additional drain tube on the left hand side linking it up to the RHS via a Y tube

Anyway, thanks again for all your help guys

Julian

[Editor]

The line of spot welds visible on the bulge from under the bonnet are where the tray is attached. Between the tray and the bulkhead there is a rubber gasket. When water gets into the seam, it causes rust, which pushed the spot weld joint apart and lets more in. That's the real problem.

I heard someone on here removed the tray from below to do a proper job.

This is for a '72 - I'm not sure if there are any small differences for other years.

[FASTY72]

I have been repairing this area on my Fastback recently so I decided to add a few pictures of my solution.
After cutting the top of the outside off to get access to repair the rust I decided to make an access flap so it is easy to keep the drain hole unbloked and also to reapair if it does rust in the future.




Its not finished yet but you get the idea. I will put a rubber seal along the front edge to prevent water leaking into bonnet area. Once painted it should look cool.
Hope you like.
Paul

[Editor]

The hoses are glued into drains that come out behind the fuel tank.

You can just about see the top of one in the last photo, but it's here more clearly

[kembiff]

Whilst you are about it and its raining heavily outside...anyone got a good tip for cleaning surface rust off the metal slats that lead into the airbox.. I wondered about some sort of bottle brush made of wire - if I can find one. I'd sooner not take the air box out if I dont have to! What other bodge tools have people on here made?

[Editor]

Bear in mind these procedures are for a Type 3. I don't know how different it is on a Type 4.

I've spent today cutting the top off my airbox - it's a lot worse than either here, or the Fastback I did several years ago. Still, it'll be alright in a few days I hoipe.

If you dribble oil in there, make sure the tray is sealed or it may come out of the front onto your carpet/mat.

[kembiff]

This is what I meant:
Beetle first - similar problem.


Fudge 412 second - you can see the rusty bit.


How can I get the rust rubbed back in this air box section without taking everything apart?

[Editor]

I don't think you can. It was made to last 10 years or so, and wasn't expected to give any problems in that time. If it looks reasonably sound, ie not crusty rust, I suggest some waxoyl in there and put up with the smell until it stops!

[kembiff]

Ah - I'm surprised that there isnt something fiendishly clever thats been invented for that job! I can see an opening in market - if only work didnt keep getting in the way I could now be on the way to my first £million!! There must be loads of old cars with similar gratings that need a good scrub!

[purplepeter]

Maybe something like a dremel?
Or a wife with small fingers..I'm sure it was Dave who made his wife rub down some wing vents?
Or perhaps a small child?With small fingers?-I'm sure half my childhood was spent cleaning my dads car,& pressing the brake pedal whilst he used every Naval expletive under the sun

[kembiff]

OK - Assuming its fine with the childrens act! Hoe do I get further in to clean the base of the dreaded pit? ...and then, how would you sort of upside down spray the underneath of the grid?

Perhaps I need to wrap sandpaper round a shrew on a spring on some string then get a cat to chase it down the vent?