Upper Heater Hose

[rtaylor]

I almost have all of the hoses replaced in my car. Picked up the replacement upper heater hose from MSA on Friday. Installation on the engine side is a breeze. So next I look under the dash to see where and how the hose connects to the heater core. Keep in mind I have AC on the 71Z, so that cramps my access on the passenger side interior foot well. The hose is secured with the original Datsun hose clamp. But here's the rub. It looks like the clamp was installed before Datsun put the glass and the dashboard in on the assemble line. The phillips head screw on the clamp is pointed towards the sky. Which means there is no way possible to get to it save pulling the dash and perhaps the windshield. There is very little room to get to anything on that side of the heater core from under the dash.

Any thoughts guys?

[Arne]

I just pulled the heater box out of my '71 last week. Granted I don't have A/C, so my access is better. But if I'm envisioning this correctly, the hose in question comes through the firewall and turns 90 degrees and onto the heater core nipple. And the hose clamp screw will need to be accessed from the top?

So here are my thoughts, none of which are guaranteed, as I don't have A/C, and don't have my car or heater box here at work to look at.

First, is there room to get a stubby or right angle Phillips in there? I use these to get to a lot of this kind of stuff. Once you get it loosened just a bit, you should be able to spin the clamp to give normal access.

Another option might be to attempt to grab the threaded end of the screw with a vice-grips and loosen it that way. As with the angled Phillips, once you get it loosened just a bit you should be able to spin the clamp. (You are planning to replace the clamps anyway, aren't you?)

And lastly, if the above don't work, you might consider cutting the hose off with a knife and removing the heater box itself. Sounds drastic, yes. But less drastic than pulling the dash and windshield.

[rtaylor]

Thanks for the quick response Arne. There is no way to get a stubby on that darn clamp. There is only 1/4 inch of space between the top of the screw and the bottom of whatever is above the hose. I could cut the heater hoses. Good advice about removing the heater box, didn't think of that. I can look in the manual to see how to remove it. I am work as well and don't have current access to my manual. No way to get any type of vise grip on the bottom of the screw either, not enough room.

Maybe I can put a cutting wheel on my Dremel and just cut the clamp. I can't remember if there is even enough room to do that. I'll have to look tonight. Yes sir, I plan to replcae the clamp too, especially if cutting it works.

[Arne]

Hmmph. My FSM never mentions the heater at all. No pictures, no description, and it doesn't even show in the wiring diagram. I don't know what complexity the A/C adds, but pulling the heater box requires dropping the blower box, pulling some ducting and about 6 bolts that hold the heater box to the firewall. Then the heater box can be slid out to the right side into the passenger footwell.

Good thought on cutting the clamp. There's plenty of room in my car to get the Dremel in there, but again the A/C may mess up that plan too.

I found that most (if not all) of the foam seals on the heater box are badly deteriorated from age. You amy want to consider pulling the heater box for that reason anyway.

[a7dz]

I agree with Arne on the seals. You can see where they were if you touch it. It is no longer. With these heaters being marginal in colder areas my not be a bad idea at all. I do not have the air conditioning to deal with either. How ever I did have the dash out when I took the heater box out. No I did not take the dash out to address the heater hoses. I was repairing some rust in the cowl and fire wall area. I did cut the heater hoses as they were toast any way.

[moonpup]

Just another thought. Check and see if you have access to the heater control valve (what the heater hose clamps on to). If you do, you might be able to remove it from the heater core and be able to pull it down for better access. You may have to cut the hose first.

Good luck.

[AZ-240z]

Another thought.

I don't have my Z with me, right now, but why don't you just drop the A/C evaporator as it is bolted to the firewall with either 3 or 4 machine screws.

Then remove the blower motor. This is fairly simple. You will, then have clear access to to hoses and heater box. Just a thought.

Dan