Tie in a 1/4" airbrake hose into the rear air brake of coach?

[Philliec]

Hello,

I just bought the M&G auxiliary braking system for my Jeep Wrangler. The Jeep portion of the install looks straight forward, but I am unclear as to how to tie into the rear airbrake line on the drive axel of the coach. I have a 2008 HR Neptune XL.

By all accounts it appears that I unscrew the 3/8" service air line at one of the air brake diaphragms and use what M&G calls a 'Street T' which is a male into the air brake diaphragm and female for newly unscrewed air line and a 3/8" to 1/4" reducer to the new air line to the rear of coach to be used by the toad.

They say they service line is closer to the rear axel and should be stamped on the can, but that is still a bit of a crap shoot. THe one I think is close to the axel horizontally, but the other is closer to the axel in the vertical direction???

Anyway, if anyone has experience on this does this sound reasonable? I am in Gunnison, CO with no RV shops, but I do have a few friends that understand air brakes. They will be doing this, but I would appreciated some guidance from this group before we all start just to make sure.

[Mr_D]

You can hook up either at the distribution fitting or at the "can". On the '02 DSDP I put a new fitting on the distribution fitting. On the present rig there was a "T" was already on the "can" at the wheel, although the end fitting was missing off the other end! Either one works. Drove the rig for several thousand miles and never noticed that the one rear brake wasn't engaging due to the open line.

[Spk64]

Here is a picture of a new can. Assuming yours to be similar. Most are marked on the can as to which is the emergency or service brake fitting.
Fitting on left is the service brake fitting. This fitting is also closer to the brake actuator rod or axle side.
Look at yours as related to attached picture and not how it might be mounted.
Fitting on right is the parking/emergency brake release fitting. And it is further from the actuator rod or axle.
Actuator rod is on the left side in the picture. This attaches to the clevis that actuates the brake.



Steve

[Philliec]

Now I understand. A picture is worth 1000 words. Thank you very much. I think I will put the Tee at the can since I have the picture Thanks.

[GreaTOne65]

Philliec, I have done this little operation twice, once on a Discovery, and on my Beaver. I would not put a fitting down on the air brake can, to much movement and shock from the road. I followed the line up to the fitting on the frame, then teed off from there. Not as easy, but I think it's out of harms way and I have had zero problems. Just my $.02

[Mr_D]

Originally Posted by GreaTOne65

Philliec, I have done this little operation twice, once on a Discovery, and on my Beaver. I would not put a fitting down on the air brake can, to much movement and shock from the road. I followed the line up to the fitting on the frame, then teed off from there. Not as easy, but I think it's out of harms way and I have had zero problems. Just my $.02

That's my preference also, but the Magna came set up that way so I left it. I guess I could go redo it. On our rig it's easy to follow the lines since the green lines are the brake lines.

[10Boomer]

Originally Posted by GreaTOne65

Philliec, I have done this little operation twice, once on a Discovery, and on my Beaver. I would not put a fitting down on the air brake can, to much movement and shock from the road. I followed the line up to the fitting on the frame, then teed off from there. Not as easy, but I think it's out of harms way and I have had zero problems. Just my $.02

This what I heard also. I can help when I finish with my install appointment on the 21st of this month.


Sent from my iPhone using iRV2 - 2008 Monaco Camelot 40 PDQ

[Philliec]

Thank you all. I just came out from under the coach. Now I can easily identify the Service line from the emergency brake. I also see your point by not Tee'ing off of the can that is quite low, but higher up at the manifold (?) away from everything (including my reach). There is lots of room up there.

There appears to be a 1/2" to 3/8" brass reducer at the manifold or at the can too. I guess just unscrew the air line leaving the brass reducer in place.

I have dumped all the air from the RV. Make sense to leave it that way until after tying in the 'T' to avoid a rush of air?

[Philliec]

My coach has a 1/2" brass tubing thread coming out of the valve for the service line that goes to one of the rear diaphragms. With a 7/8" box wrench it should be removable, but it was not and I am afraid that I might screw up the brass hex if I pull too hard. My guess this brass fitting is pipe thread in the valve that converts to tubing thread where the air brake line attaches. Using a box wrench I pulled hard, but it did not budge. My 'T' fitting is all pipe thread. I have a 1/2" pipe to pipe thread adapter that I can use if I could remove the existing brass fitting. Any suggestions in removing the 1/2" brass fitting at the valve?

[GreaTOne65]

Philliec, my guess is it has thread locker, or pipe dope compound. Did you take the hose off? You should be able to put a box wrench on it? If I remember right I had to use two wrenches one on the distributor and of course one on the fitting. If there is room, a simple gas torch should loosen any thread locker. Good luck.

[Philliec]

As tight as it was I was suspecting something like locktite or something. I am not sure what all is in the valve that could be impacted by a torch, but it is worth a shot. Thanks. I will first try for a 1/2" female tubing thread to 1/2" male pipe thread adapter to screw into the T. That would be the easiest fix.

[Spk64]

It just takes a little heat to break down the loctite. Do not over do it. Heat a little then try breaking loose then maybe a little more heat if needed.


Steve

[Philliec]

OK. Got the M&G install done. The RV part was probably the easiest. I put the T just off the manifold. Checked and have lots of air coming out the rear with brake pressed.

The 2012 Jeep was a bit time consuming cutting out the plastic dam for the ABS system and getting a feel where the M&G was in there just right. Too long and the brakes would always be on. Too short and there would be too much play. Now there is no slop in the Jeeps brakes and I drove for over 2 miles and coasted a long time to a stop with no heating at all for the front rotors. Now I need to test this whole system out on the road. That is next, but for now it is Miller time.

[Slice]

How about posting pic of where u tied into rv brake line. I am right in line behind you to do this to my rig. But you got most of the answers to my exact questions.