Remember to Torque Check your A/C Mounting bolts

[Calbar]

Rob,

Thank you. The other Rob brings up a great point where a one time torque that takes gasket compression into account makes sense. I would hope they did their homework and know just how far the gasket will compress over time and the first torque would take care of this. But how do we know the first torque was done properly?

Interesting topic.

Jim

Agreed Jim,

Sent Dometic customer support an email this morning with the questions about the torque value and checking torque as well as how often and to what level. As soon as I hear back I will post the response.

Rob

[Canyonlight]

Whoever thought simply tightening down AC bolts/nuts would be so involved ! Will need to check both our new low profile Dometic installed by GDRV 2 years ago and our original Atwood (again.) Thanks guys !

Dan

[TENN22]

This forum spends my money faster than a trip to the Tampa RV show!

[Country Campers]

This forum spends my money faster than a trip to the Tampa RV show!

This is the finest support group to be apart of .

Brian

[TENN22]

This is the finest support group to be apart of .

Brian

You are correct!

[Calbar]

So I just heard from Dometic and they don't want to provide any maintenance information. Concerned about liability apparently. The stated that this should only be done at the service center and never by the owner.

Either way I have torque checked mine and will continue to do this on a regular basis unless there is a RV tech here that has the appropriate information from Dometic that they will not share with owners.

Rob

[Guest]

So I just heard from Dometic and they don't want to provide any maintenance information. Concerned about liability apparently. The stated that this should only be done at the service center and never by the owner.

Either way I have torque checked mine and will continue to do this on a regular basis unless there is a RV tech here that has the appropriate information from Dometic that they will not share with owners.

Rob

Most likely if a leak is reported, the service center would replace the gasket and torque based on both the spec as well as the observed gasket compression.

b. Tighten mounting bolts to correct torque specifications. Overtightening could damage unit’s base pan or ceiling template. Not enough torque will allow an inadequate roof seal, and could cause a leak. Tighten all four (4) mounting bolts EVENLY within 40 to 50 inch pounds. See (FIG. 16). This will compress the roof gasket to approximately 1/2″.

So it looks like this is a one time procedure which makes re-tightening a gray area since the gasket may continue to compress each time the bolts are tightened. Maybe a simple water test and a visual inspection of the installed gasket height would be good enough.
Maybe a call to a service center may shed some light on this?

Jim

[Calbar]

Most likely if a leak is reported, the service center would replace the gasket and torque based on both the spec as well as the observed gasket compression.

b. Tighten mounting bolts to correct torque specifications. Overtightening could damage unit’s base pan or ceiling template. Not enough torque will allow an inadequate roof seal, and could cause a leak. Tighten all four (4) mounting bolts EVENLY within 40 to 50 inch pounds. See (FIG. 16). This will compress the roof gasket to approximately 1/2″.

So it looks like this is a one time procedure which makes re-tightening a gray area since the gasket may continue to compress each time the bolts are tightened. Maybe a simple water test and a visual inspection of the installed gasket height would be good enough.
Maybe a call to a service center may shed some light on this?

Jim

I am taking my 297RSTS in to the dealer on Monday for the Molex recall and will ask about it and see what they say.

Rob

[JBill9694]

This thread lead me to do a quick check on our AC's I found one mounting bolt that I could wiggle by hand, all the others were tight. I don't know if the one bolt was loose from the start or loosened overtime. But I like the idea of checking the torque or seeing if the bolts can be wiggled better than trying to check with water.

[Guest]

This thread lead me to do a quick check on our AC's I found one mounting bolt that I could wiggle by hand, all the others were tight. I don't know if the one bolt was loose from the start or loosened overtime. But I like the idea of checking the torque or seeing if the bolts can be wiggled better than trying to check with water.

I would have been tempted to check the torque on the remaining bolts by starting low and moving up in small increments. Then examine the before and after gasket compression at the four corners of the unit..

Jim

[Calbar]

This thread lead me to do a quick check on our AC's I found one mounting bolt that I could wiggle by hand, all the others were tight. I don't know if the one bolt was loose from the start or loosened overtime. But I like the idea of checking the torque or seeing if the bolts can be wiggled better than trying to check with water.

I had one wiggle too and I agree with you that I would rather check the torque than wait for a water problem.

Rob

[Retgw2]

Here is a link to an article (https://rvlife.com/air-conditioner-bolts/) where the author suggests checking and tightening the AC bolts. His recommendations only go as far as hand tightening and then an additional quarter turn. I'm not sure what that equates to in inch-pounds of torque but it seems like it is more leaning towards removing excessive play than going for a complete torque to installation specs that would most likely compress the gasket further. I had a loose AC unit on my previous trailer that allowed water to get in so I'm interested to see what Dometic or the Dealership recommends.

[Calbar]

Here is a link to an article (https://rvlife.com/air-conditioner-bolts/) where the author suggests checking and tightening the AC bolts. His recommendations only go as far as hand tightening and then an additional quarter turn. I'm not sure what that equates to in inch-pounds of torque but it seems like it is more leaning towards removing excessive play than going for a complete torque to installation specs that would most likely compress the gasket further. I had a loose AC unit on my previous trailer that allowed water to get in so I'm interested to see what Dometic or the Dealership recommends.

Dometic's response was to take it to a service center and have the do it. They would not provide any information. Quoted liability issues. Will see what the dealer says when I take it in for the Molex recall on Monday. See if they are anymore helpful.

Rob

[Crespro]

Hello,

This list-serve is certainly worth the price of admission. I just torqued the eight AC bolts on my new 310 GKR. Seven needed substantial tightening. I followed the suggestion of Rob and used about 30 to 35 inch pounds of torque. Thanks!

Charles

[Guest]

Here is a link to an article (https://rvlife.com/air-conditioner-bolts/) where the author suggests checking and tightening the AC bolts. His recommendations only go as far as hand tightening and then an additional quarter turn. I'm not sure what that equates to in inch-pounds of torque but it seems like it is more leaning towards removing excessive play than going for a complete torque to installation specs that would most likely compress the gasket further. I had a loose AC unit on my previous trailer that allowed water to get in so I'm interested to see what Dometic or the Dealership recommends.

Interesting article. I read some of the comments and a few had tightened their bolts which resulted in a leak or made a leak worse. Certainly if a bolt is falling out it would need to be tightened.

Jim