M1009 eating vac modulators

[Dodgeman1941]

Hi Guys,

My M1009 just ate another transmission vacuum modulator. This won lasted about a year. The previous one also lasted about a year. What might be making the tranny so hungry for vac modulators? Am I missing something simple or is there a bigger problem?

Thanks,

Lew VB

 

[rnd-motorsports]

What is wrong with the modulator why do you say its bad? just asking the only way I have ever seen a modulator bad was a blown diaphragm they leak trans fluid when you pull the vac line off if thats the problem maybe just bad luck! did you adjust it when you put it in I hear peaple turning the adjuster screw several turn,s they dont like more than about 1 turn either way you get the correct one for the aplication the colored stripe is the tension of spring inside if you turn the adjuster more than a turn will put more presure on the diaphragm and shorten it's life.

 

[tm america]

never had a problem with the failing from how they are adjusted.one thing that might be happening.Maybe someone put a stop leak additive in there which would cause the diaphram to swell and might cause it to fail rapidly....or maybe you got them from a place that doesnt sell many of them and they were sitting on the shelf way to long.remember they could have been on the shelf 40 plus years and still look new..but rubber doesnt last that long ..

 

[rnd-motorsports]

about being on shelf and be old! (Just bad luck!)

 

[Dodgeman1941]

The "pre-first" one was bad and leaking when we got the truck. The first one was from NAPA, and it worked great and the truck shifted when it should when it first went, it would shift to soon and when it would shift to second, it would then shift to third almost immeditly. And then shortly after that it started to leak. Changed to second mod {from Advanded Auto} and it went back to shifting properly. Second one just started to shift early this weekend after an hour long trailer hauling trip. So I figured this one is also on it's way our. Adjusting...these didn't have any adjustments on it, they both were the basic versions. Between #1 and #2 we did a fluid and filter change on the truck.