Replacing Your Heater Control Valve

Maintenance advice to keep your Spider in shape.
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moss1972
Posts: 56
Joined: Thu Sep 05, 2019 8:36 am
Your car is a: 1979 Fiat Spider 2000

Replacing Your Heater Control Valve

Post by moss1972 »

Hey Gang,

I conquered, no I slayed my heat control valve install on my 1979 2000. This included removing a kinked hose that someone put in, rather than buying a 90-degree hose as well as corroded valve fitting, stuck bolts and working in a tight space.

If you're thinking of replacing your heat control valve. This is a good video for sharing my tips in a way to give back to the community for all YOUR helpful posts.

https://www.youtube.com/watch?v=drIftZTya10

Caio!
Steve
MA/NH
1979 Spider 2000
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Replacing Your Heater Control Valve

Post by 18Fiatsandcounting »

Well done! Can I hire you to work on my car? Replacing the heater valve on a spider ranks pretty highly in terms of PITA exercises. Let's just hope you don't need to go back and replace the heater core... :P

-Bryan
User avatar
moss1972
Posts: 56
Joined: Thu Sep 05, 2019 8:36 am
Your car is a: 1979 Fiat Spider 2000

Re: Replacing Your Heater Control Valve

Post by moss1972 »

    18Fiatsandcounting wrote:Well done! Can I hire you to work on my car? Replacing the heater valve on a spider ranks pretty highly in terms of PITA exercises. Let's just hope you don't need to go back and replace the heater core... :P

    -Bryan
    Thank you and I hope NOT!!!!

    Honestly I’m more intimidated by the brakes! The stories I hear about bleeding rival the cooling system procedure.
    Steve
    MA/NH
    1979 Spider 2000
    18Fiatsandcounting
    Posts: 3798
    Joined: Fri Mar 15, 2019 11:23 pm
    Your car is a: 1969 and 1971 124 spiders
    Location: San Francisco Bay Area

    Re: Replacing Your Heater Control Valve

    Post by 18Fiatsandcounting »

    Well, if it's any consolation, I haven't had too much problem bleeding the brakes on my Fiats over the years. I'm old school, in that I have my wife push on the brake pedal while I crack the bleeder screw and drain the fluid into a clear Tygon tube (or the like) that is attached to the bleeder screw nipple. I find it easier to put the whole car up on jack stands with tires removed so you can quickly go from one caliper to the next. Start at the furthest one from the master cylinder (passenger rear), then driver rear, then passenger front, then driver front. Then repeat as often as necessary until no more bubbles or cloudy-looking fluid. It can take one or two 12 oz cans of brake fluid.

    Two tips: 1) crack the bleeder screw just barely (too much and air can leak past the threads back into the system) and 2) raise the rear of the car by the axle. If you raise the rear by the body, the rear brake "compensator" can kick in and limit the fluid movement to the rear brakes. The compensator is sort of a "poor man's anti-lock brakes" in that it limits brake fluid pressure to the rear when the car pitches forward under heavy braking so as not to lock the rear wheels. Note that in these older cars, the compensator is often shot... Something else to replace, and that can be a pain as the two brake line fitting nuts to it are hard to get to. Penetrating oil, mild heat, and a flare nut wrench definitely help. Waving chicken bones with incantations works for some people...

    -Bryan
    User avatar
    moss1972
    Posts: 56
    Joined: Thu Sep 05, 2019 8:36 am
    Your car is a: 1979 Fiat Spider 2000

    Re: Replacing Your Heater Control Valve

    Post by moss1972 »

    18Fiatsandcounting wrote:Well, if it's any consolation, I haven't had too much problem bleeding the brakes on my Fiats over the years. I'm old school, in that I have my wife push on the brake pedal while I crack the bleeder screw and drain the fluid into a clear Tygon tube (or the like) that is attached to the bleeder screw nipple. I find it easier to put the whole car up on jack stands with tires removed so you can quickly go from one caliper to the next. Start at the furthest one from the master cylinder (passenger rear), then driver rear, then passenger front, then driver front. Then repeat as often as necessary until no more bubbles or cloudy-looking fluid. It can take one or two 12 oz cans of brake fluid.

    Two tips: 1) crack the bleeder screw just barely (too much and air can leak past the threads back into the system) and 2) raise the rear of the car by the axle. If you raise the rear by the body, the rear brake "compensator" can kick in and limit the fluid movement to the rear brakes. The compensator is sort of a "poor man's anti-lock brakes" in that it limits brake fluid pressure to the rear when the car pitches forward under heavy braking so as not to lock the rear wheels. Note that in these older cars, the compensator is often shot... Something else to replace, and that can be a pain as the two brake line fitting nuts to it are hard to get to. Penetrating oil, mild heat, and a flare nut wrench definitely help. Waving chicken bones with incantations works for some people...

    -Bryan
    I’ve done my wrangler and after doubting myself and my pedal feel took it to be power bled. No difference. I used a similar system to your procedure. Thanks for the tips. I’m most eager to learn how to remove calipers step by step and do a video as there’s NO step by step with tips on how to deal with those shims holding it in the bracket. I’m used to just two caliper bolts and the caliper comes off. I’m most concerned about getting the hoses off the hard brake lines without busting anything. As you said, penetrating oil, mild heat, cleaning the threads like I did with the heat valve and just working it patiently. I had read about the compensator in the Manuel mentions raising by the axle which to me is the most efficient way anyway. Thank you again I really appreciate it.
    Steve
    MA/NH
    1979 Spider 2000
    SteinOnkel
    Posts: 1000
    Joined: Tue Feb 19, 2019 9:31 pm
    Your car is a: 1978 124 Spider 1800

    Re: Replacing Your Heater Control Valve

    Post by SteinOnkel »

    Excellent video, will look into this. My heater is always on. A bit annoying.

    Allow me to return the favor (I've done the caliper removal many, many times. It is super easy now. )

    1. Remove the wheel
    2. Remove all eight little clips that hold the shims
    3. Take a BIG flat screwdriver and a hammer
    4. Gently tap out the shims to the back, using the screwdriver as a chisel
    5. Once you get the first one out, it's game over. Take the caliper and move it up and to the left smartly. Now pull out the second shim.

    Installation is a bit more tricky.

    1. Place the caliper (roughly) to where it will sit after you install the shims. Make sure it is resting against the anti-rattle spring.
    2. Take your first shim (doesn't matter which one, top or bottom) and slide it into caliper. If you're confused about the orientation, take one of the other wheels off and look at those calipers or your reference images. It may need a bit of motivation from a (PLASTIC, not metal!) hammer.
    3. Get it about halfway in for now.
    4. Grab your trusty big flat screw driver and slide it into the upper (or lower, depending on which shim you've already installed halfway) slot where the shim will eventually go. Hammer the screwdriver in gently, again about halfway.
    5. Now install the second shim from the back side, keeping your screwdriver in place to create a gap. Set the shim with your hands and when you are convinced it can physically slide into place motivate it to do so by gently tapping it with a plastic hammer in a "come hither" motion.
    6. You know you're doing it right when the shim pushes the screwdriver out. Let it do so. Once it's far enough in to expose its two little holes for the clips, you are done. Install the clips.
    7. Again using the screwdriver and a small hammer tap the bottom ship far enough that you can install the rear clips.
    8. Install all remaining clips.
    9. That's it, you're done.

    It helps immensely if you use some sandpaper or better jet a bench grinder to take off all the corrosion of the involved metal surfaces. DO NOT use penetrating oil, it may seep into your brand new pads, causing catastrophic brake failure.

    Cheers
    Steiny
    User avatar
    moss1972
    Posts: 56
    Joined: Thu Sep 05, 2019 8:36 am
    Your car is a: 1979 Fiat Spider 2000

    Re: Replacing Your Heater Control Valve

    Post by moss1972 »

    SteinOnkel wrote:Excellent video, will look into this. My heater is always on. A bit annoying.

    Allow me to return the favor (I've done the caliper removal many, many times. It is super easy now. )

    1. Remove the wheel
    2. Remove all eight little clips that hold the shims
    3. Take a BIG flat screwdriver and a hammer
    4. Gently tap out the shims to the back, using the screwdriver as a chisel
    5. Once you get the first one out, it's game over. Take the caliper and move it up and to the left smartly. Now pull out the second shim.

    Installation is a bit more tricky.

    1. Place the caliper (roughly) to where it will sit after you install the shims. Make sure it is resting against the anti-rattle spring.
    2. Take your first shim (doesn't matter which one, top or bottom) and slide it into caliper. If you're confused about the orientation, take one of the other wheels off and look at those calipers or your reference images. It may need a bit of motivation from a (PLASTIC, not metal!) hammer.
    3. Get it about halfway in for now.
    4. Grab your trusty big flat screw driver and slide it into the upper (or lower, depending on which shim you've already installed halfway) slot where the shim will eventually go. Hammer the screwdriver in gently, again about halfway.
    5. Now install the second shim from the back side, keeping your screwdriver in place to create a gap. Set the shim with your hands and when you are convinced it can physically slide into place motivate it to do so by gently tapping it with a plastic hammer in a "come hither" motion.
    6. You know you're doing it right when the shim pushes the screwdriver out. Let it do so. Once it's far enough in to expose its two little holes for the clips, you are done. Install the clips.
    7. Again using the screwdriver and a small hammer tap the bottom ship far enough that you can install the rear clips.
    8. Install all remaining clips.
    9. That's it, you're done.

    It helps immensely if you use some sandpaper or better jet a bench grinder to take off all the corrosion of the involved metal surfaces. DO NOT use penetrating oil, it may seep into your brand new pads, causing catastrophic brake failure.

    Cheers
    Steiny
    FANTASTIC WRITE UP! Thank you for the finesse tips and penetrating oil warning. That’s perfect! I can tell you’ve got a very experienced system there. I’ll put it to use.
    Steve
    MA/NH
    1979 Spider 2000
    User avatar
    moss1972
    Posts: 56
    Joined: Thu Sep 05, 2019 8:36 am
    Your car is a: 1979 Fiat Spider 2000

    Re: Replacing Your Heater Control Valve

    Post by moss1972 »

    18Fiatsandcounting wrote:Well done! Can I hire you to work on my car? Replacing the heater valve on a spider ranks pretty highly in terms of PITA exercises. Let's just hope you don't need to go back and replace the heater core... :P

    -Bryan
    And yeah Bryan if you’re ever in MA Illl gladly help you work on your car. Or you can pay me if I don’t break anything too important. LOL
    Steve
    MA/NH
    1979 Spider 2000
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