I have a moen 1 knob push-pull faucet for my tub/shower. When I push it in sometimes water continues to drip. It is probably 30 years old. Are their replacement parts for it?

The dripping is most likely the water draining back down from the shower riser. Is the diverter button popping back out when the water is shut off?

probably have a kink on how water line feeding valve..if possible to cut drywall bhind tub valve and inspect pipe at bottom plate...moen faucets are equipped w/ anti scald device, pressure balanced (newer models) and this could cause cold water to overwhelm hot water...

Call Moen directly. They will ship what you need to your door, for free.

The faucet was installed upside down.
The shower riser pipe in the wall is to short( the distance between the faucet and shower head).
One of the biggest problems is if your shower faucet was installed with Pex pipe to the tub spout. Pex pipe will restrict the flow and force the water back up and out of the shower head.
The tub spout must be piped with at least 1/2 brass pipe nipples and fittings, or 5/8 OD. copper pipe and fittings.
Hope this helps, if you further questions please let us know.

I could not find an exploded parts diagram for the Benton suite from Moen. I did find the bayhill which is very similar. Please see link below of exploded view. That should help you piece it back together.

New moen cartridges for tub/showers come with a handy white plastic tool to aid in old cartridge removal. One end is squared off for a wrench, the other is slotted to place over the old cartridge in the wall after the clip has been removed. Place onto cartridge and use a wrench to turn several times back and forth. Remove , grab the stem with pliers and give a tug. You want either service part #1225B (pull/push to turn on) or #1222 (just turn knob counterclockwise to turn on. Get the replacement before you proceed.

push down the tub-spout lift rod and it will empty the remaining water that is between the shower valve and the tub spout

the water deverter that makes water come out the shower head is probably in need of repair. or replaced.

Single handle shower controls always have some water trapped inside. It has probably freeze damaged the cartridge

hi... yes that's a very common issue with moen "cartridges" -- it's very simple to fix..... grasp the handle and give it a gentle tug upwards when the water is on... if it retracts again, pull the handle out again and tug again but this time a bit harder. Not sure what causes this on new cartridges but it will fix your issue.