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Topic: Tightening your A/C's (Read 549 times) previous topic - next topic

Tightening your A/C's

I read a post recently where someone mentioned tightening the roof mount A/C mounting bolts once a year.  I had not heard of this, and while I've never had a leak, I decided to check mine today.  The Dometic Penguin II manual states to torque them to 40-50in-lbs.  It took about 8 turns on my rear A/C and 6 or so on the front A/C to get them to spec. 

Just thought I'd throw this out there as a reminder to anyone that hasn't checked these in a while, or ever.
Keith
2003 U320 38' #6197

Re: Tightening your A/C's

Reply #1 –
And be careful not to over-tighten or do so unevenly.  The gaskets will permanently deform and you'll wind up having to replace them due to leaks.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Tightening your A/C's

Reply #2 –
Do NOT compress the gasket more than 50%.

The problem with quoting torque specs is that corrosion and wear due to vibration can significantly impact torque vs gasket compression.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Tightening your A/C's

Reply #3 –
When I did the gasket on my coach I found pieces of interior wall plywood used as shims while foam had been squirted in the space. So the 1 inch thick standard gaskets were too thick.
88 Grand Villa 36' ORED 3208 (throwaway)Cat.
 Build # 3150
Happiness is the maximum agreement of reality and desire.

Re: Tightening your A/C's

Reply #4 –
Quote from: wolfe10 –
Do NOT compress the gasket more than 50%.

The problem with quoting torque specs is that corrosion and wear due to vibration can significantly impact torque vs gasket compression.

Any rig I've had that I felt like it was time to add torque to the air conditioning mounting bolts I replaced the gasket at that time - Doesn't take that much more effort if you're worried about a leak... But then there's the unexpected cleaning project that ensues! 🤣
2000 Foretravel GV320 4010 #5717
"SuperDutyFiver" on most other boards

*** East coast based - literally "all over the east coast!"

Re: Tightening your A/C's

Reply #5 –
Quote from: SuperFore –
But then there's the unexpected cleaning project that ensues! 🤣

And the inspection and likely reinforcement of the shrouds at the screw holes  :D
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Tightening your A/C's

Reply #6 –
Quote from: Michelle –
And the inspection and likely reinforcement of the shrouds at the screw holes  :D

Yup, stainless steel fender washers with a rubber gasket between the washer and shroud really spreads the load and extends shroud life.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Tightening your A/C's

Reply #7 –
I did like Wolfe said: SS washers and gaskets, also primed the plastic and painted all with spray cans to reduce UV deterioration, and the old yellowing was not pretty.
David & Emma Roche
Dino (Golden Doodle)
1999 U270 WTFE 36' Build # 5534
Xtreme "Lights, Stripes & Roof"
Motorcade# 18321
Dayton, Ohio
Towd: Jeep Grand Cherokee
Two Townie Electra Bikes

Life is made to enjoy, the Foretravel helps!
 

Re: Tightening your A/C's

Reply #8 –
DUH. Me being an idiot savant injinear, I went a different route from the "included instructions" that came with my new AC seals.
I turned the adhesive side of the foam seal UP and put caulk down on the surface that contacts the coach roof....on both ACs.
Seems contrary to what everyone else does but---BUT!!!!!!!!!!!!! That was about seven years ago and haven't tightened any bolts or had any leaks whatsoever. Our coach sits out in the weather all summer and is in a covered building during the winter except when we went to South Texas for the winter, so my seal method must work.
I must admit, I forgot about tightening the bolts every year. DUH!!!!
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD