1977 Heater Flappers Removal Challenges

[7783911]

I realize i need to replace a cable on one side but have the while in there attitude to do both sides. Despite every contortion known to man, I was only able to get PB blaster on the cable attachment and 2 of the flapper bolts. The manuals make it sound easy to get flapper boxes off..but i am seriously doubting that. Does anyone have advice on how bast to tackle this job (remove flappers, clean and restore, re install with new cables and seals) without a lift. Do i remove rear wheels to obtain more access or is a lift required given the brake and other cables that get in the way (resulting in PB blaster in the eyes from underneath)

ideas, hints, photos all welcome

[75 911s]

I would definitely put it up on jack stands all the way around in order to get max room to work. Place one of the tires under the tub for security as you will be tugging on the flapper box a bit to get it to break loose from the gasket.

Take the 3 nuts off and grab a hold on the pipe end of the flapper and start pushing up and down. Mine popped off after some force was applied. The gaskets melt and get old creating like a glue like surface between the box and the chassis.

Search flapper box there are a few step by step rebuilds.

[john walker's workshop]

If they don't really have to come off, best to leave them alone. The studs often break off due to rust.

[mnez]

I successfully replaced my very rusty ones some years ago by heating the nuts with a small butane pencil torch, and then spraying with penetrating oil. Repeat the process several times for each nut before attempting removal. Use a small box end wrench so you can visualize the nut and stud. You need to get it hot enough that the oil smokes and evaporates instantly, then soaked more. Let it dry up and repeat.
Once the nut cracks loose, work it back and forth with oil to gradually get the nut off.
More about technique than force.
Even then, there is a high probability of snapping off the studs.
Unless you are comfortable with this, and have good experience with rusty fasteners, you likely should just leave them alone.

[bkreigsr]

Originally Posted by john walker's workshop

The studs often break off due to rust.

nightmare

BTDT

[7783911]

i ve been soaking in PB blaster and hope to access a lift so i can go at them gently...if they snap then swearing will be followed by drilling out the studs and inserting capture nuts?

[7783911]

do you have a picture of the pencil torch?

[bkreigsr]

Originally Posted by 7783911

i ve been soaking in PB blaster and hope to access a lift so i can go at them gently...if they snap then swearing will be followed by drilling out the studs and inserting capture nuts?

Not a lot of elbow room under there for that kind of work.
Good luck

[mnez]

Originally Posted by 7783911

do you have a picture of the pencil torch?

Something like this, refillable butane.

[Flat6pac]

Well, experience tells me that you can say goodby to the top stud...
Bruce

[Walt Fricke]

Agree that you should expect to break at least one stud. I did. Fortunately, two are enough. Though you could fix broken studs. Drill the broken one out, and insert Rivnuts or the like, and use bolts to reattach. Or drill out, and do a nice tiny weld to hold a new stud in place.

Agree best to leave alone if you can get the old operating wire off with them in place, and they work.

[7783911]

I will make that call once i get the car up on a lift, the bodies of the flapper boxes are in rough shape and i had hoped to sand blast clean, redo the bushings and hw, paint and replace. Plus I am not convinced they are closing 100% internally.

that said..if the nuts prove to be too difficult then I will revert to plan B which is replacing what I can w/o removal and clean it up in situ.

Thanks

[7783911]

got the nuts off clean but cant get flapper to budge//like its glued on!..any suggestions?

[sedouglas72]

The flapper boxes are the only two items left on my car other than the fuel tank because I could hear them telling me that they were going to snap off on me. I guess I'll just go ahead and snap them off and plan on putting rivnuts in their place...

[Walt Fricke]

Tapping joint with a very thin chisel? Or something thinner, like a putty knife?

[ErrorMargin]

Originally Posted by Walt Fricke

Tapping joint with a very thin chisel? Or something thinner, like a putty knife?

Putty knife and a small hammer did it for me.

Thanks for the suggestion.