Dishwasher outside air gap leak

[Gleudson]

Hi

I have a 2002 house that has a Johnson tee air gap with a cap outside of the house.
The outside cap has 3 holes and it is leaking and it is probably clogged.
I made this conclusion reading some threads in this forum.
How can I unclog it? Should I remove the cap? Just unscrewing it? I am concerned on making the problem worse.
Please see pictures below. Any advice is welcomed.
Thanks in advance

Gleudson

 

[Jeff H Young]

Its plugged Not sure how to clear it, trying to go down a 3/4 pipe would be hard. probably gunked up at the p-trap inside the wall . but not familiar with Washington style I would expect an 1 1/2 " p trap in the wall.
It would probably blast out with water or shop vac it out and plug holes in cap when doing it . could use air but quite dangerous not recommended only very low pressure

 

[Sponsor]

 

[Gleudson]

Its plugged Not sure how to clear it, trying to go down a 3/4 pipe would be hard. probebly gunked up at the ptrap inside the wall . but not familiar with Washington style I would expect an 1 1/2 " p trap in the wall.
It would probebly blast out with water or shop vac it out and plug holes in cap when doing it . could use air but quite dangerous not recomended only very low pressure

Thank for the insights, yeah i dont know what is behind the wall or where it could be clogged. It seems that the drain is not clogged though it is leaking in the outside cap with the 3 small holes.

 

[Reach4]

Enter the following search using the search box above: johnson dishwasher

 

[Jeff H Young]

Thank for the insights, yeah I don't know what is behind the wall or where it could be clogged. It seems that the drain is not clogged though it is leaking in the outside cap with the 3 small holes.

That would be a major symptom of a stoppage downstream of Johnson tee as reach 4 said google it you'll get images of how it works

 

[Terry]

The Johnson Tee has a 1/2" line from the dishwasher which then goes into the top of the tee, which is on a 1.5" standpipe with p-trap, then going into a 2" kitchen waste line.

They make an insert for the 3/4" end with rubber seals when used on the interior of a home. When pointed outward it's a 3/4" PVC cap that gets drilled for venting at trim out. The picture above was taken at McClendons Hardware Woodinville.

 

[Jeff H Young]

Clearly its a stoppage below or at the Johnson tee . I've never seen one in practice but That's How I see it I'm sure Terry has opinion on causes. The design in picture kinda sucks because the access isn't so good but my guess very easy to clear.
Just gotta get busy with it now Gleudson

 

[Gleudson]

Thanks to all for the responses. I will unscrew the cap and check if there is something at the Johnson tee and also snake the 1/2".

 

[Tuttles Revenge]

The plastic cap on the exterior is glued on. it needs to be cut off and later replaced with the mushroom cap that Terry shows above.

 

[Jeff H Young]

I'd probably blast it out like a condensate have somebody hold a rag over the vent holes simple enough but you Washington guys should have tricks might be able to run a fish tape up the copper

 

[Gleudson]

Thanks to all comments....Right now, the leakage is not big, then i have time to plan and do things carefully. Here is my idea....based on the comments...I want to, first, try to remove the debris at the JT before attempting to remove the cap. So I was thinking on blowing air (low pressure) from the cap wholes to move debris to a different position, then try to blast water or even blow air on the drain connection as suggested above.

 

[Terry]

If you're going to do that, I would pick up the mushroom fitting and cut the cap off to allow a better job of fiddling with it.
I've installed a ton of the Johnson tees over the years, and have had a few times where things weren't draining down the standpipe into the p-trap. It was not an easy fix.

 

[Jeff H Young]

Even a shop vac might do it put some tape over the holes and carefully remove hose with shop vac on. Agree it might not be real easy , especially in comparison to doing nothing but its pretty basic stuff .
I wouldn't expect the blockage at the tee, but down stream of it

 

[Tuttles Revenge]

I'm with Jeff.. But also you could use the shop vac to blow air in as well. its not super high pressure, so less likely to be harmful.

 

[Reach4]

If that exterior piece is threaded as in Terry's second photo, rather than glued, two rods thru holes, and held by pliers, might allow unscrewing.

 

[Tuttles Revenge]

If that exterior piece is threaded as in Terry's second photo, rather than glued, two rods thru holes, and held by pliers, might allow unscrewing.

The OP posted a photo of a PVC cap.. most assuredly glued. I've never seen a threaded version. In Terrys photo, you might be seeing one of two ridges that retain the O-ring that seals the cap in the pipe.

 

[Gleudson]

Thanks to all. Blow did work!