Hey mates

It appears that the one piece rubber outer hatch seal - the thin one that goes outside - is broken an allowing rainwater in. I've had issues installing these in the past - I've broken two right out of the box when I shut my hatch. Is there a special way of doing these where they don't break? Is there any rubber seals I should avoid? Any place to get OE ones?

Cheers
Jan

The outer (thin/narrow) seal is just a first line of defense (a deflector) to keep water out but is not the main seal.  If you are getting water into the cabin, then your inner seal is not doing its job.  Check to see that it is snug against the hatch all around and that it is firmly glued in place and not moving when the hatch closes.  The outer seal is available in a three piece set - similar to OE, or a one-piece option from MSA.

Not sure why you've had problems, 'breaking these when I close the hatch'.  Maybe you can explain where the problem is occurring.  Pix #1-3, below, were posted by another CZCC member (sorry, no name to credit) and show the OE-style, 3-piece outer seal.  It uses a bulb-type seal across the top and around the upper corners.  After that, the bottom pieces on the left and right are -- as Jim says -- really just water gutters, rather than seals.  The aftermarket, one-piece seal uses a bulb design along its entire length

In my experience, the top piece was difficult to install properly with the hatch in place.  Also, the metal lip on which this seal mounts isn't that deep, so you shouldn't really rely on just a mechanical fit to hold the seal in place.  Some judicious use of weatherstrip cement is called for here (see photo #4).  If you've just been pushing the seal into place and hoping for the best, that may be the source of your problems.

When I worked on my car years ago the one-piece bulb profile was not yet available.  I ordered the OE-style pieces but didn't like the side transition from bulb to the "L" shaped sides - even though that's how the Nissan engineers designed it.  I returned the side pieces and bought two more uppers, cut off the corners and made a continuous bulb profile for the sides.  As @Namerow says, installing the top section is a real PITA with the hatch installed - been there, done that!

10 hours ago, Namerow said:

Not sure why you've had problems, 'breaking these when I close the hatch'.  Maybe you can explain where the problem is occurring.  Pix #1-3, below, were posted by another CZCC member (sorry, no name to credit) and show the OE-style, 3-piece outer seal.  It uses a bulb-type seal across the top and around the upper corners.  After that, the bottom pieces on the left and right are -- as Jim says -- really just water gutters, rather than seals.  The aftermarket, one-piece seal uses a bulb design along its entire length

In my experience, the top piece was difficult to install properly with the hatch in place.  Also, the metal lip on which this seal mounts isn't that deep, so you shouldn't really rely on just a mechanical fit to hold the seal in place.  Some judicious use of weatherstrip cement is called for here (see photo #4).  If you've just been pushing the seal into place and hoping for the best, that may be the source of your problems.

To explain the last time I did this which was a few years ago I took the hatch off - in the process almost breaking it - installed new seals and waited a few hours for them to dry in place. Then I put the hatch back on and when I went to close the hatch the freshly placed seals were literally ripped off by the hatch closing. I live in Arizona so it doesn't rain very often but when it does my whole interior gets pretty wet. Both the inner and outer seals broke on the top, but just along the top.

Hmmmm... this sounds like a hatch alignment problem to me.  The outer seal should be under the thin lip of the hatch but not under any of the thick part.  If the thick part of the hatch is contacting the outer seal when closing, the hatch is too close to the body suggesting the hinges are missing some shims.  The closest the thick part of the hatch should be to the outer seal is to very slightly touch it when the hatch is fully closed - it should nestle inside that seal, never press down upon it.

Now, as to the inner seal: if it is breaking away when the hatch is closing it is likely the hinges are contacting the seal and knocking it loose.  The seal shape you have may not be formed correctly to clear the hinges.  A friend had a similar ongoing problem and he ended up buying a new inner seal from MSA - one by PRP I think.  Here's a pic of my inner seal, also by PRP.  The vertical rib to the left fits into a recess on the underside of the hatch and the change in the shape to the right allows the hinge to clear.

Hope this helps you in diagnosing the problem.

18 hours ago, jfa.series1 said:

Hmmmm... this sounds like a hatch alignment problem to me.  The outer seal should be under the thin lip of the hatch but not under any of the thick part.  If the thick part of the hatch is contacting the outer seal when closing, the hatch is too close to the body suggesting the hinges are missing some shims.  The closest the thick part of the hatch should be to the outer seal is to very slightly touch it when the hatch is fully closed - it should nestle inside that seal, never press down upon it.

Now, as to the inner seal: if it is breaking away when the hatch is closing it is likely the hinges are contacting the seal and knocking it loose.  The seal shape you have may not be formed correctly to clear the hinges.  A friend had a similar ongoing problem and he ended up buying a new inner seal from MSA - one by PRP I think.  Here's a pic of my inner seal, also by PRP.  The vertical rib to the left fits into a recess on the underside of the hatch and the change in the shape to the right allows the hinge to clear.

Hope this helps you in diagnosing the problem.

Shims? I did not know that the hatch had shims, I didn't see any when I took mine off.

44 minutes ago, Pomorza said:

Shims? I did not know that the hatch had shims, I didn't see any when I took mine off.

Sometimes there are shims behind the hinges. I haven't ever seen them between the hatch and the hinge, but I have seen them between the hinges and the body. If the panels don't sit right they could be used in in either location.

I presume you have the rubber boots installed for the hinges.  Do you also have the thin plates below that keeps the boots from deforming?  This is not a shim per se but it somewhat acts like one.  These plates are not available as a Nissan P/N, were originally packaged with the OE boots as an assembly.  There is a shim listed as a P/N, not all cars required them, see item #24 on the link below.

http://www.carpartsmanual.com/datsun/Z-1969-1978/body-240z/tail-gate-panel-trim-lock-rear-bumper

24 minutes ago, jfa.series1 said:

I presume you have the rubber boots installed for the hinges.  Do you also have the thin plates below that keeps the boots from deforming?  This is not a shim per se but it somewhat acts like one.  These plates are not available as a Nissan P/N, were originally packaged with the OE boots as an assembly.  There is a shim listed as a P/N, not all cars required them, see item #24 on the link below.

http://www.carpartsmanual.com/datsun/Z-1969-1978/body-240z/tail-gate-panel-trim-lock-rear-bumper

Those little shims can be hard to source. As well as the hinge boots. I found mine on Ebay several years ago for reasonable money...

These are the kinds of parts that are great to strip off of junk yard dogs. NLA and hard to find...

Among all of the assorted little bits of hardware that I've accumulated over the years is a 'slotted' shim plate (lower row, centre, in the photo below).  I could never figure out what it was intended for...  until now!

If you find that you need something like this, it shouldn't be that difficult to to make up a pair from some sheet stock.  Maybe make two or three pairs, so that you can stack them.  If you go with metal, rust will be an issue so brass would be best (if you can find it this thick). It might be easier and better, though, if you make them from 1/32" or 1/16" clear plastic sheet stock.  A little more fragile for installation, but easier to fabricate and zero rust issues.  A quick cruise of your local hardware store's shelves should turn up lots of items that could be used as material donors.

1 hour ago, Namerow said:

Among all of the assorted little bits of hardware that I've accumulated over the years is a 'slotted' shim plate (lower row, centre, in the photo below).  I could never figure out what it was intended for...  until now!

If you find that you need something like this, it shouldn't be that difficult to to make up a pair from some sheet stock.  Maybe make two or three pairs, so that you can stack them.  If you go with metal, rust will be an issue so brass would be best (if you can find it this thick). It might be easier and better, though, if you make them from 1/32" or 1/16" clear plastic sheet stock.  A little more fragile for installation, but easier to fabricate and zero rust issues.  A quick cruise of your local hardware store's shelves should turn up lots of items that could be used as material donors.

Some fine, aged Canadian patina you have there.