Brake Valve air leak. How can you reach it?

[CountryB]

Has anyone worked on (replaced or repaired air line leaks) at the Brake Treadle valve?

I have a leaking supply line but cant reach it to work on it. The brake valve is sandwiched between the firewall and front cap. I tried to access myself and could not fit. I took coach to repair shop and they could not reach it either. I guess I would have to cut an access hole in the front cap/fiberglass if the valve ever needed to be replaced. For now I live with the leak.

Did Beaver really design the Coach this way (cant service or replace the brake valve without cutting a hole in the front cap)?

2005 Beaver Patriot Thunder (Roadmaster M10 chassis).

[vito.a]

Maybe route a new air line and bypass the old one.  

[CountryB]

Hi Vito. I wish I could reroute around this air leak somehow, but the air leak is at the supply line at the "push-to-connect" fitting which is threaded into the brake valve. There is no rerouting fix.

[Ivan K]

I looked at mine and it also looks like potential nightmare but the lines come in through a box welded to outside firewall and the box appears to have a riveted bottom. I think this would be my access point. Certainly painful no matter what. I will refrain from using the adjustable pedals for no reason, to avoid straining the lines from now on.

[Frank McElroy]

10 hours ago, CountryB said:

Hi Vito. I wish I could reroute around this air leak somehow, but the air leak is at the supply line at the "push-to-connect" fitting which is threaded into the brake valve. There is no rerouting fix.

Is the leak on the air line going into the "push-to-connect" end or where the connector threads into the valve?  If the leak is on the end where the air line pushes in, remove the air line and make sure the airline end is cut square and there is no side pressure on that line.  Then be sure the air line is fully inserted.  If you don't know how to disconnect an airline from a "push-to-connect" fitting, by pushing in the end of the fitting release mechanism with an open end wrench, there is likely a description in your owners manual or just do a YouTube search.

[jacwjames]

I can access mine through the firewall, I only have a plastic box that is mounted over the treadle valve.  The box is held in place with screws and heavy bead of black caulk around the edge.   I removed the box in an attempt to find spare wires to wire in a pressure fuel gauge, which I didn't find but at least I learned what was behind the black box.

[CountryB]

Hi Jim,

I could not find a way to access the brake valve looking from under the dash. Perhaps I need to dig around inside the dash board area a little deeper. I would make sense that the manufacture would provide some sort of access. Your post gives me some hope. 

BTW - regarding the reply from Frank, the air line is leaking at the internal o-ring where the nylon tubing/line pushes into the "push-to-connect" fitting (not the NPT side of fitting). But since I cant reach the brake valve, I can't replace the fitting (or trim the end of the tube and reinsert).

On the other fittings located throughout the Coach of this push-connection design - when they leak, I replace the entire fitting with the  "DOT compression style" fitting. I've replace many around the Coach so far. They always seem to leak (after 15-20 years when the o-ring dries out/wears out).  The compression style never leak... 

Thanks

 

P.S. Frank I'm originally from Flemington area. Small world.

[jacwjames]

Mike,

Slide your generator out and look on the firewall in front of the area the brake pedal is, I'd be surprised if there was not some sort of access in that area

Here's a picture of mine, the black box on the right is access for my treadle valve

[vanwill52]

My major air leak was from the CONNECTIONS to the treadle valve.  I never verified the treadle valve itself leaked.  But all the lines were cut too short and exited the treadle valve in a bind.  The lines need to all leave straight out of the fittings, not pulled to one side.

How did I replace it?  I didn't do it myself...I'm just not flexible enough.  I hired a wiry 20-something to contort himself in the confined space and fix the problem by splicing in additional line to each treadle valve connection, such that none would be under any strain to one side or another.

[CountryB]

I appreciate all the replies and suggestions. I have tried to figure out a way to reach the leaking fitting but it cant be done without removing the generator (or cutting an access opening in the fiberglass/cap).

Since the leak is not that bad (not a problem when engine is running), I'm going to leave it as is for now - and come back to it later is necessary.

[Frank McElroy]

Keep in mind that DOT air brake test requires no more than a 3 psi loss in air pressure per minute with tank pressure above 100 psi and the engine off.  Also with the engine off, no more than 4 psi loss per minute in air pressure with brakes applied.  If your coach can't pass both requirements it would be classified as out of service and unsafe to drive.

[jacwjames]

If the tests that Frank suggest doing fail removing the generator may have to happen.  On my coach with the generator fully extended I have pretty good access to the whole firewall but it looks like your access is smaller.  

If you have a good location and tools pulling the generator and or whole slide out tray isn't that bad.  On mine have to disconnect full and return lines, remove boh the + & - battery connections, disconnect the communication control wiring on the side, and disconnect the 240 volt wires, the exhaust.  If you had a small lift you could remove the whole tray, I only have two stops that hold it in place.  The generator has 4 bolts that attach it to the tray.  I was able to remove mine by myself. 

 

[Ivan K]

Maybe removing the top and side (which is one piece with the rear) generator cover would give just enough elbow room when it comes to it? But a total removal would not be such a big deal either, with a pallet jack. I would not be cutting the cap.

[Bill R]

@CountryB I am sure you have looked at this from every angle.  But could you build ramps, and with the coach raised a bit get to it from the back side with the generator fully extended?  Meaning being under the coach to do the work.  Maybe your generator doesn't fully extend like mine does.

Edited April 30, 2023 by Bill R

[vanwill52]

I do not think your treadle valve is significantly more difficult to access than mine.  I could "see" how I could have done it thirty years ago, so I assumed a flexible young man could do so.  I was right.  It took a bit of "pride-swallowing" to pay someone to do such a simple job, but the labor charge was only a couple of hours and was WELL WORTH IT.  Of course, I have developed a close relationship with a heavy truck shop owned by Christian missionaries, whom I trust absolutely and completely.  I trust them not only to give me an accurate estimate, but also to do quality work.  I always discuss with them any particulars about how I want any job to be done.  They have never disappointed me.  It took several years of bringing them jobs too physically difficult for me to do myself, and being reasonable when they ran into "problems unforeseen".  I also praised their efforts, tipped them, pay in greenbacks, and always donate to their Kenyan ministry.  They own motor homes (gassers) and do quite a bit of work on motor homes.

I mention this to bring home the fact that many of us, due to infirmity...or simply age...find some tasks that we are willing to pay someone to do for us, as long as we trust their integrity and skill.  I would encourage all of you to develop a relationship with an INDEPENDENT truck shop.  It may take several trips to their shop to have something done on your coach, and develop their trust in YOU, just as you develop your trust in THEM.  Were it not for my relationship with this shop, I think I would have to resort to Cummins Coach Care for many tasks, and the closest one is many miles from me, not to mention their reputation for integrity and quality work is neither stellar nor ubiquitous.  Have reasonable expectations, discuss your proposed job in detail, then see how they do.

I add this as a final paragraph, in the event that Scotty or Dave think I should not mention a particular shop.  But if they do not object, I ENTHUSIASTICALLY recommend Leenheer's Truck and Auto repair in Carthage, NC.  They are a family business staffed by the husband-and-wife team of Jeff and Karen Leehheer, aided by their son Kyle (a very accomplished heavy truck mechanic), SIL Louie (the wiry guy who replaced my treadle valve and tubing), Brittany, and several friendly mechanics.   This is not a shop that does only oil changes and replaces spark plugs (although they recently added a "quick oil change" to their repertoire in a separate building.  Jeff pays a decent wage and only recruits outstanding mechanics.  At any time, you will find their shop with the entire body of a heavy truck removed so they can replace the engine or other major component.  They replaced both the engine and transmission in my 2000 Silverado in the last couple of years.  Jeff PERSONALLY rebuilt the transfer case on the Silverado, since I did not want a "rebuilt assembly".  I knew Jeff would do a better job than I would get from any "remanufacturing" supplier.  Leenheer's services ALL my rolling stock. I have never been disappointed in them.

[jacwjames]

A mechanic who use to work at the mines I manage is the one I trust for jobs I can't or don't want to do.   For some reason he thinks highly of me, and I do of him.

I never question his judgment on what it takes to fix something.   He knows my vehicles and if I go to his shop I just leave the key in at a note or just the part I need to replace.  The starter on my Jeep was going out so I bought one with the intent to replace myself, NOPE my fat hands wouldn't reach any of the connectors and I didn't have a "special tool" so I just left it at his shop with the starter on the front seat, he called me when it was done.  And for some reason he won't charge me what I think a job is worth, so I'll usually add $$$ depending on what the job was. 

So I'm with Van, If you have a good shop or mechanic treat them well and you will be rewarded. 

[Happycarz]

Not knowing exactly where your treadle valve is, this may or may not work. Just something for you to think about.

What about putting a crow’s foot wrench on an appropriate length extension and push it against the release ring? If you could release the culprit and at same time pull on the tubing, either by hand or with the aid of long handled pliers, remove the tubing, cut of 3/8” and reinsert. A little soapy water would help getting it seated.

I find the area of the nylon tubing “shrinks” due to the constant pressure of the O ring. When the O ring gets new territory to seal on, the leak stops. Now and then a O ring gets nicked during the original assembly and take years to fail, but not very likely. 

I found on my coach and at my car washes that the ¼” tubing  just had the end of the tubing necked down where the O ring seats.  I just fixed a rear dump valve on my coach last week by trimming the end off. I have yet to experience one of the larger lines leaking. Fingers crossed.

Of course I’m assuming that you can move the end of the tubing within cutting distance . I sure would be nice to get it resolved. 

[CountryB]

Thanks again for taking the time to reply.

I have a set of ramps, and I can get under the Coach to do most of the work needed. But the Treadle valve can not be reached from below. I had the AC condenser and fan out, but still cant get to the valve form the bottom. I can just about get to the backside of the headlights.

I then took Coach to Josams (Truck frame/repair shop in Orlando) were they have a pit (and lifts) and they could not get to valve either. Cost me $75 to hear that.

There is nothing to remove on top of generator that will help. There is a large frame member (the cradle/frame surrounding generator. The frame you can see just above my light in the photo) blocking access from reaching in (only the camera fit in far enough to get the photo above). Generator would need to come out - but that is better than cutting a hole in the fiberglass cap..

If (when) I get access, I will be replacing the push-to-connect fittings with the compression style. However the leak is slow enough now that I'm not going to worry about it until it gets worse. 

[Happycarz]

I feel your pain.

The completed Roadmaster chassis comes into the assembly line and the floor and body is then built on it. Not all systems are easily accessed, as many of us know.
 

I just finished replacing the evaporator/heater core box on my firewall. It was no picnic.  The plastic deteriorated at several places. Every other box I have looked at is pristine. Why me? Just because I can, doesn’t make it right.