modulator valve sucking tranny fluid up?

[BigRedTruck]

the truck started shifting into second later than it should and harder too, then it got worse, and worse, and worse. the local shop replaced the valve but said to take it to a transmission shop. they mentioned this might have fouled a plug or two....is there anything else I should look out for? all this happened after my new carb was put on. thanks.

[DuckRyder]

Most of the replacement modulators are adjustable. There is a small slotted screw inside the nipple.

Also make sure there is an minimum of rubber hose, and that it is in good condition.

[68F250]

A backfire can blow out the modulator valve diaphragm and then you'd be sucking up tranny fluid along with having late shifts like you said. Did you already replace the valve? Then it should be back to the normal short shifts. Visually check your spark plugs but they're probably ok.

[BigRedTruck]

the shifting is still a bit harsh compared to the later shifts but it is better other than that thanks.

[BigRedTruck]

it drove great for a bit then started doing it again. i think i am backfiring but am unsure how to correct this. since there are so many possible sources. bad timing i think was listed in the troubleshooting guide and my dad does not remember EVERgetting the points adjusted. is the is the mostly likely cause?