Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Jan & Richard on April 15, 2015, 06:40:56 pm

Title: Drilling of Frame Rails
Post by: Jan & Richard on April 15, 2015, 06:40:56 pm
I am in the process of installing an Air Force One supplemental braking system.  One step requires the mounting of the "Coach Air Connection Assembly" which consists of  valve assembly and small air tank.  This assembly is to be mounted near the rear brake valves on the coach.  There is a very obvious place to mount the assembly but would require drilling a couple of holes in the main frame rail, and then tapping the holes for mounting bolts. 

My question, "Is the frame rail mild steel or is it some kind of high tensile steel that would not be worth trying to drill?"

Thanks,

Richard
Title: Re: Drilling of Frame Rails
Post by: Pierce & Gaylie Stewart on April 15, 2015, 06:58:49 pm
Check with Foretravel before drilling. Several of our fire trucks were placarded for no drilling or welding on the frame but others do it all the time. We had two trucks that developed fairly short cracks (2 or 3 inches) in the frame starting from rivets. The factory and insurance required the rigs be junked.

Pierce
Title: Re: Drilling of Frame Rails
Post by: John Haygarth on April 15, 2015, 07:02:46 pm
Post a picture of were you would like to drill etc. If it is at the end of the rectangular tubing down either side of engine it will be ok IMHO
JohnH
Title: Re: Drilling of Frame Rails
Post by: Barry Beam on April 15, 2015, 07:08:16 pm
I am in the process of installing an Air Force One supplemental braking system.  One step requires the mounting of the "Coach Air Connection Assembly" which consists of  valve assembly and small air tank.  This assembly is to be mounted near the rear brake valves on the coach.  There is a very obvious place to mount the assembly but would require drilling a couple of holes in the main frame rail, and then tapping the holes for mounting bolts. 
My question, "Is the frame rail mild steel or is it some kind of high tensile steel that would not be worth trying to drill?"
Thanks,
Richard
I had my Air Force One system installed in Quartzsite. When I was leaving the other day I went to plug in the air line and the bolt holding the bracket snapped off. I had to drill a new hole next to it using titanium bits I bought for drilling some stainless steel. I started with a small hole and worked my way up. I love these titanium bits. In the rush to leave I did not think about tapping the hole but now that it was brought up it would have been better to tap it.
Title: Re: Drilling of Frame Rails
Post by: Jan & Richard on April 15, 2015, 07:32:14 pm
The holes I want to drill would be in the rectangular tubing beside the transmission, not in the end of the tubing. 

I will e-mail Foretravel tomorrow. 
Title: Re: Drilling of Frame Rails
Post by: rsihnhold on April 15, 2015, 07:57:13 pm
The holes I want to drill would be in the rectangular tubing beside the transmission, not in the end of the tubing. 

I will e-mail Foretravel tomorrow. 

I installed mine right behind the passenger rear tire mudflap where I access my starting batteries.  I just used normal drill bits and tapped whatever size I needed.  Haven't had any issues in the 3+ years its been on there.
Title: Re: Drilling of Frame Rails
Post by: Barry & Cindy on April 15, 2015, 08:21:39 pm
The air-relay (aka Coach Air Connection Assembly or CaCa) unit can be installed anywhere.  Many install it near engine rear access door.  No reason to crawl under coach to maintain the unit.  Run nylon air hose to air supply, brake can and to coach's rear air disconnect.  I have no idea why they specify a particular installation location.  I would not drill or mount to frame.
Title: Re: Drilling of Frame Rails
Post by: Jan & Richard on April 15, 2015, 08:28:25 pm
Thanks Robert and Barry.  Tomorrow I will check out alternate mounting locations. 
Title: Re: Drilling of Frame Rails
Post by: nitehawk on April 15, 2015, 11:07:39 pm
After fifty years in the metal working industry I learned a new trick from an installer I had come in to fabricate stainless steel coolant guards on one of my machines.

His "trick"? Pulsate your drill so you vary the rotations per minute. This lessons the chance of the material work hardening in front of your drill bit. I have used that trick ever since and not had any work hardening issues since.  ^.^d  ^.^d
Title: Re: Drilling of Frame Rails
Post by: rbark on April 16, 2015, 12:15:57 am
Jan and Richard, I mounted mine in the eng compartment just in front of the air intake pipe on that ledge that's about 8 inches wide. Easy access. Will take a picture of it tomorrow.
Title: Re: Drilling of Frame Rails
Post by: Jan & Richard on April 18, 2015, 10:47:52 am
To follow up on my Air Force One install, I mounted the Coach Air Connection Assembly to the angle iron hangers for the chassis battery tray on the passenger side of the coach. 

The entire installation on both the coach and toad went very smoothly.  A test drive proved everything is operating as it should.  It took me a good portion of two days, mostly reading and rereading instructions and figuring how best to make a clean install.  Thankfully my coach documents included a good schematic drawing of the air system; without it I would not have had nerve to cut into the coach's air brake lines. 

Thanks for all the responses.  And Nitehawk, thanks for passing along your "trick" for metal drilling.  I will try to remember and use it.