Reinstall AC - bolt torque

[RVcircus]

I put the AC unit back on the roof and tightened the bolts enough to make a decent seal and mush the gasket just a bit. Is there a torque spec for these bolts that I should be shooting for? I didn't want to go too tight to start with, so I temporarily tightened enough to where I thought it wouldn't leak sitting in the driveway.

[path1]

http://www.youtube.com/watch?v=69hwGiIqGoU

Around the 2 min mark is tightening info you might want.

[Dick_B]

Try a Google search for `bolt torque chart' for info.

[LarryJM]

Old-Biscuit wrote:
New gasket is 1" thick and should be compressed about 1/2"....that is for new one.

The hold down bolts should be 'snug'.......so what is 'snug'?
Hand tighten then 1/4 turn with wrench.

Torque.....20 INCH Pounds (Notice: That's INCH Pounds not foot pounds). Very few folks have and know how to use an INCH torque wrench so that is why 'Just SNUG'

The amount of compression for new is correct and there is a torque value and not sure if the above benchmarks are correct, but they concepts are right.

For new I would use the compression amount and for older units torque to the specified value whatever that is and I'm assuming 20 INCH-LBS is correct.

Larry

[RVcircus]

Thanks everyone. I'm reusing the old gasket as it's only 2 years old and still in good shape. I intentionally left it loose, but still may have over tightened it. I'll recheck and torque to 20 in lbs which should be about finget tight.

The problem I was having is that all the weight is on the rear of the unit so I pulled it down from the inside and hand tightened the bolts. Once I had everything snug I made 3-5 turns on each bolt.

[path1]

You don't say if your using a new gasket or re-using old one. Doesn't make that big of difference as long as you get nice even fit. (If your going to buy a new one at some point...I bought on at RV dealer and found out later I paid about twice what I could get on-line for. Didn't realize at the time so much mark up in one simple item).


Also see http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26045448.cfm

If you have the "new" type with the plastic tabs, "tight enough" is when you can see plastic tab start to compress.

No matter if you have old or new design...In couple weeks tighten again no more 1/8 turn of bolt, to make sure even fit and torque.

Then the start of RV season or when ever you do your annual maint tighten no more than 1/8 turn once a year.

I also wiped down the inside where a couple of water tracks were visible from old gasket leaking and now can inspect with flash light without removing inside cover, just to make sure no leaks from time to time. And lets me sleep better.

Should last many years, until gasket is real thin then start process all over.

(Edit part) forgot to mention. Take it real easy on those plastic air louver things on inside cover. (the little movable fins that direct the air flow). I broke one if mine and was a hassle getting new and putting in new ones.

[BB_TX]

Don't over tighten. I had a second AC installed. But when the tech got it installed it would not work. They said bad AC and ordered another one. Went back a week later to have the second one installed. But a different tech found that the first tech had over tightened the bolts on the first one and it would not let the fan turn. Loosened the bolts and retightened go the proper torque and it ran fine.

[Old-Biscuit]

New gasket is 1" thick and should be compressed about 1/2"....that is for new one.

The hold down bolts should be 'snug'.......so what is 'snug'?
Hand tighten then 1/4 turn with wrench.

Torque.....20 INCH Pounds (Notice: That's INCH Pounds not foot pounds). Very few folks have and know how to use an INCH torque wrench so that is why 'Just SNUG'

[newman_fulltime]

hand tight the more you squish the faster it will fail.You want it snug is it