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Heat exchanger/manifold query t2 2000cc
Bowen Kombi - December 18th, 2008 at 09:29 AM

Hey Guys, 1st post from me.
I have a 76 kombi in real good shape, but I had to let it sit for a few months when I went overseas.
I've just come back and have noticed that there are a few bits that need fixing up.
First up, I put in a new battery, cleaned up the burnt points and set the gap - didnt check timing, but will get round to it this weekend.
I noticed that it was a little louder than I remembered and was backfiring a little.
Have checked where the blow was coming from and removed the heat exchanger cover plate for better access. I can see where there is a little crack on the passenger side h/e casing, but figured that this would not be the cause of the blow, and would just affect the air coming through the vents - right?
Anyway looking up at the manifold flange where it meets the head (front cylinder/passenger side) I noticed that the securing nut/washer is missing, with dark soot in the general vicinity. This would seem to be the cause of my problem.
I would think that whatever gasket was there is probably toast, so I will need to get it off and reassemble it all again, or is it worth just trying to snug it up with a new nut/washer?
Does anybody know the size of the nut / thread etc and what it should be torqued at?
Are there any other consumables that I will need to take the h/e off and refit it? (i.e. gaskets, seals etc.)
My local Motor Factor doesnt carry much stuff for Kombis, and I am about to travel to the big smoke and pick up all the parts I need.

I have it on my xmas wish list to get a manual!

Thanks


Andy - December 18th, 2008 at 11:05 PM

Hi,
Welcome to the forum. You should be able to get planty of good help!
Good to hear of another kombi driver out there, they are great old machines.
It's definitely woth checking the timing and general tune of the motor, particularly in summer when old aircooled motors struggle to stay cool. Make sure you change the oil regular and check/replace all your fuel lines! (old VW's tend to have leaking issues which cause fires).

If I understand what your saying correctly, the crack you mention will not affect exhaust flow. There is a continous pipe between the head and muffler, just below the head and just short of the muffler aluminium fins are cast over the pipe , then covered in steel sheet for your heater. If this cover of the aluminium is cracked your right in saying it will not affect the exhaust flow.

Type 4 motors have a copper gasket between the top of the exhaust pipe and the head. The seal is up inside a recess in the head, and as you would know by now, not easy to get into!
I would recommend pulling the heat exhanger and replace the gaskets, they should not be expansive and most VW shops will have them in stock.
You will need the copper gaskets and the gasket to the muffler as you will be breaking that joint also. Some kits will probably include the nuts/washers as it's a good idea to replace them also.
The threads should be 8mm, but over the years the studs could have been replaced, so that's not always what they are.
Make sure you use some good anti sieze on the threads when re-installing.
Hope that helps!


Bowen Kombi - December 23rd, 2008 at 04:57 PM

Thanks for the info.
I just got into the job and have done the following:
1. Removed the sponge strip around the tinware
2. Remeved the tinware giving access to the silencer / heat exchanger joint.
3. Sprayed a release agent on the nuts threads that I could access.
4. Removed silencer
5. Undid the four nuts and washers from the h/e to the head.
6. Removed the air hose that passes through the tinware and attaches to the h/e
7. Removed the clip and 2 screws that attach the h/e to the semicircular alloy housing for the crank pulley.
8. Undid the big hose clip holding the h/e to the pipe that rises toward the flapper valve.

HOLD EVERYTHING!!

The joint that is held by the hose clip in 8. looks like it is never going to move. Does anybody have any tips as to how I should sympathetically go about separating this piece?

BTW - I have just noticed a leak from a pushrod tube. It would seem the obvious thing to sort this at the same time.