Heater Control Valve

[spidernut]

My original heater control valve started leaking from the diaphragm. I keep reading horror stories about the aftermarket ones needing to be modified to work correctly. I've heard everything from "you'll have to drill bigger holes in your firewall" to "you'll have to fabricate multiple connections to get them to fit."

Any experience with a good replacement valve?

For grins, I removed the valve, drilled out the rivets and removed the rubber diaphragm to inspect it. The diaphragm looks really simple and I can't imagine it being unique only to the Spider. Since I'm trying to keep my car as original as possible, I'm on a hunt for a new diaphragm. So far, only one rubber parts manufacturer said that I couldn't afford the cost to make a new one. Anyone find an exact fit from another heater control valve? It doesn't matter if the rest of the valve is the same as long as the diaphragm is the same.

John

[So Cal Mark]

the reason the new valves need some mods is that they are X1/9 valves. The angle for the tube is slightly different. Good luck finding a diaphragm

[mbouse]

i wouldn't call them horror stories. i did not have that degree of difficulty. my last one came with a decent set of instructions that adequately made provisions for the slight difference.

horror or Sci-Fi... which is better?

[baltobernie]

I got one for a '73 from Vick, and it was Ed Zachery like the one on the car. Maybe a PO had also replaced one?

I agree with Mike; they are not difficult to install, but you must have a flexible torso! Job would be a lot easier on a lift, where you could work standing up. I used a foam garden-type kneeling pad on the door sill to ease the discomfort on my ribs A 1/4" drive socket set and tiny wrenches are helpful, too. Remember to order the special conical washers which install between the core and valve. And be sure and carefully examine the two steel supply/return tubes for corrosion.

Now that I've detailed the job, maybe it's not so simple, after all

[mbouse]

i always grab that knee pad, set it on the floor, and then kneel down. i then set my elbows on the floor of the car, and stick my head under the dash.

this position immediately reminds me of praying.... so, i say that prayer. "help me not to curse so loud that my wife will hear me from inside the house"

hey... it usually works.

[spidernut]

I got my first quote on a diaphragm for the heater control valve which begs the following question:

If you could buy a repair kit for the stock heater control valve for about $20, would you buy the kit or a new heater control valve (that requires at least some modifications)?

The kit would take about 15 minutes to install (not counting removing the valve from the heater core and reinstalling it).

John

[daved]

I bought a heater control valve from Bayless a few years ago which came with instructions for modifications. When I installed it I found that no modifications where actually required.

[RudeDog]

Howdy John -

Okay, I got into my heater core (1978 Spider) today and I need a new heater control valve (or rebuild kit) as well. What did you decide and how did it turn out?

Daved - do you have any more info on that Bayless part?

Thanks,
Rudy

[JimM]

John--I just replace my heater control valve about a month ago. I got it from Autoricambi. When they sent it they forgot to put the instructions in the box with the part, but an email to Ramzi got the instructions that I needed. It was not a hard job to replace the valve, it just takes a little time in an awkward position. The easiest adaptation method is to cut your inlet pipe 11/2" from the fitting to the control valve and add a piece of heater hose with 2 hose clamps to secure it. This simple mod will allow you to easily slip the new control valve into place and then back to Mike's "praying" position to tighten the nuts. All was done and the heater was throwing out hot air in under an hour(including time out for a liquid refreshment). I spent more time worrying about doing the switch, because of the "Horror stories" than I did doing the job. Just remember to take your time and don't forget the liquid refreshment--very important. Have fun!! and GOOD LUCK!

Jim

[maytag]

I've been chasing leaks in the firewall lately, and I've come across an ugly hole where the heater core supply / return pipes go through. The hole looks like someone made it with a screwdriver and hammer (ugly).... but is this because they were doing a poor job of the swap to X19 components? Does anyone know?
And with that in mind, now that I have a parts-car.... what is the interchangeability of the Heater core / valve / etc between the '76 (mine) and the '80 (donor) ?

Thanks!

[narfire]

And with that in mind, now that I have a parts-car.... what is the interchangeability of the Heater core / valve / etc between the '76 (mine) and the '80 (donor) ?

Take a look a couple of topics down in fiat spider related. I had asked the same question regarding the 72-81 swap. There is a size(thickness) difference, and what I gather is one would have to swap the housing as well to use the later heater core.
I just swapped the valve as well, popular fix this time of year? not a big issue, but Mark nailed it in that the heater pipe has to be tweeked to fit between the replacement valve and the firewall. I was lucky and my 81 parts car already had the swap and I used its pipe.
I like Jims method in cutting the pipe and using heater hose, If he did not do so I might try and protect it as it goes through the wall somehow.
Chris

[spidernut]

I also bought a replacement from Auto Ricambi. I cut the pipe, scabbed in a piece of heater hose and I was good to go. The free heater core I got worked great and the valve was only $28!

[JimM]

Congratulations John on a job well done!!

Chris--I have a rubber grommet that fits in the hole in my firewall that the inlet/outlet heater pipes go thru. This grommet or gasket keeps the pipes from rubbing on the metal firewall. It also holds the pipes in their correct places. I thought that this was a stock set up, but it could be something the po put in. After fixing some of the wiring changes the po did I would lean more towards the stock set up.

Jim

[MNspiderman]

I've grown accustomed to leaky valve, even in my Alfa. New valve price $toomuch. I simply solder a 3/8 to 1/2 copper pipe adapter from HomeDepot. The 3/8 end fits on the heater core side and the 5/8 or 13mm heater hose fits right over the 1/2 copper perfectly. Then I procede to get a cable operated shut off valve and mount it under the hood like 95% of all older US cars. Simply put a longer cable onto the Hot/cold lever and run it outside the firewall. Works great and saves about 150 bux. If you want your car authentic do not do this. If you want the hot water stopped before it enters the firewall, do this.