Community Forums

hooptie00 · 04-24-2018, 09:34 AM

I'm at my witts end and could use some advice.

Our M/H is a 1997 Tiffin Allegro Bus with 2 Duo Therm units, I replaced the gaskets on both when we got it 3 years ago. The rear unit seals fine and we have had no problems with it.
The front unit will not seal. I have replaced the gasket 3 times now and have followed just about everybody's directions at this point. I even bought a Inch Pound torque wrench.

The problem is that water enters at the front bolts but not all the time. Leveling the coach doesn't appear to be a factor.

The last 2 times I replaced the gasket I caulked the top of the 2 front bolts where they go up through the pan. The first time, I did a pretty good job. The last time I was OCD to get them completly sealed at the top pan. No dice.
When it leaks, water runs down the bolt threads then through the interior A/C grill. It doesn't really get the ceiling wet. We just put a pan underneath to catch the drippings.

The vent drains are clear and to the best of my knowledge have never been blocked.

I'm afraid to try to seal the threads because it might cause the water to travel in a different direction and really do some damage.

So, has any one experienced a similar problem?

I'm open for any solution, 2 gaskets, spray foam, alien intervention, whatever will just stop the water from running inside.

TIA,

J R

Quincy · 04-24-2018, 10:47 AM

Quote:

Originally Posted by hooptie00

I'm at my witts end and could use some advice.

Our M/H is a 1997 Tiffin Allegro Bus with 2 Duo Therm units, I replaced the gaskets on both when we got it 3 years ago. The rear unit seals fine and we have had no problems with it.
The front unit will not seal. I have replaced the gasket 3 times now and have followed just about everybody's directions at this point. I even bought a Inch Pound torque wrench.

The problem is that water enters at the front bolts but not all the time. Leveling the coach doesn't appear to be a factor.

The last 2 times I replaced the gasket I caulked the top of the 2 front bolts where they go up through the pan. The first time, I did a pretty good job. The last time I was OCD to get them completly sealed at the top pan. No dice.
When it leaks, water runs down the bolt threads then through the interior A/C grill. It doesn't really get the ceiling wet. We just put a pan underneath to catch the drippings.

The vent drains are clear and to the best of my knowledge have never been blocked.

I'm afraid to try to seal the threads because it might cause the water to travel in a different direction and really do some damage.

So, has any one experienced a similar problem?

I'm open for any solution, 2 gaskets, spray foam, alien intervention, whatever will just stop the water from running inside.

TIA,

J R

Were they leaking when you replaced the gasket the first time?

Since you have replaced the gaskets more than once could the water be coming from somewhere else?

Like the drain pan which is supposed to drain to the front corner gutter.

Could water from the evaporator coil be blowing off onto the grate?

If none of these suggestions help then it must be the Russians.

Good luck and keep us in the loop please.

hooptie00 · 04-24-2018, 12:32 PM

Hi Quincy,

When we got the M/H I didn't really see where it was leaking before replacing the gasket.

The roof was replaced just a few years before and was garage kept, so it appears to be in perfect shape.

It leaks even when not running the A/C.

I caulked the heck out of the bolts where they come up through the drain pan and it still leaks down through the bolt threads as the bolts are located inside the gasket.

I really hope it's not the Russians. I have enough problems as it is.

Thanks,

J R

Rkesselus · 04-24-2018, 08:15 PM

Just thinking about my experience with RV AC install What you describe has nothing to do with the Ceiling gasket and how water is getting to the install bolts. You say the water is following the bolts down. I have installed both ducked units and non ducked and the attaching bolts which do nothing more than squeeze the top unit to the interior flange unit and are not in a position where water should be encountered either from rain or from condensation.
There are several UTube videos on the installation of RV AC's Might be well to take a look and see if what they show is what you did. I agree with you and don't think the Russians have anything to do with this but maybe as you point out someone from Hell might. Good Luck Richard

hooptie00 · 04-24-2018, 09:22 PM

Hi Rkesselus,

I agree that's what makes it so confusing.

I have replaced several gasket sets on different RV's we have owned. never had a problem with them sealing down.

It would be easier to understand if after 3 tries it would fix the problem. I just can't understand why the same installation procedure would work on the rear A/C and not the front. Same unit, same gasket, same torque.

Maybe if the water was entering someplace other than the bolt threads it might make sense.

I'm at a loss, maybe someone has had this problem too and can offer some support.

Thanks for the response,

J R

Bob Hyatt · 04-24-2018, 09:49 PM

You might try taking one of the mounting bolts to your local auto parts dealer. Find the thickest o-rings you can find that fit the bolt reasonably snugly. In the world of boats, this is a HUGE issue, as in the bolts that attach a motor's jack plate to the transom. We generally GENEROUSLY coat each bolt with 3M 4200 adhesive/sealant, where the bolt already has its washer installed if there is one (also a little 4200 between washer and bolt head). Now force some in the mounting holes and use a small probe (like a large drift-pin tool) to get the interior of the holes well coated. Finally put some around the bolt on the other side, then the washer, then a little more, then the nut and tighten away. No water is coming through that hole/bolt.

IF, and notice the big IF, the hole through the ceiling has a good "corner" in and out, the o-ring might do the trick. Otherwise, here comes the 4200. Next time, go to walmart and buy a .410 shotgun bore cleaning brush, chuck it up in your drill and clean the hole and repeat.

hooptie00 · 04-25-2018, 06:04 PM

Hi Bob,

Now that is a really good idea. I just happen to have a box of about 500 O rings in various sizes sitting in the garage. Now that you mention it, I remember that trick form my sailboating days.

I can always count on the IRV2 members to come through for me.

I have a new gasket set on the way and will give it a try.

When all is said and done I'll shoot you a PM to let you know how it worked out.

Thank You,

J R

Frank Miller · 04-25-2018, 07:03 PM

JR, when you pull the A/C and examine the roof and gasket, is there any place where you can see evidence of the water getting through the gasket? Unless the unit is leaking water through the case, you should be able to see somewhere on the gasket where it isn't adhering properly to the roof. The bolts are likely providing a path but aren't likely the source of the leak. However, if you examine the bolt connections carefully, you might be able to see a trace of how the water is getting to the bolt location. a water leak will almost always leave some kind of a trail that can be seen if you look closely in the right place.