This evening after filling the propane tank at Tractor Supply , when I released the air brake to leave, a hissing immediately began. It turned out that one of the valves on the back of the parking brake was leaking air. I attached a picture below. Air was hissing out of each of the three wire holes - and when I removed the wire harness, air gushed out of the remaining fixture.
No air loss when the brake was engaged, only when released. Was able to make it home - PSI on dash was fine, but leveling warning ding and dash display would come and go periodically during the drive. Tried to engage the leveling system after parking and putting on the parking brake, but despite the system display appearing normal, no noticeable changes occurred.
1) Does anybody know the name of exactly what I'm pointing at in the picture? I looked at Barry Beam's part listing for the 2003, and there are about 7 different air brake valve types listed.
2) What's the next step - do I replace the entire fixture or is there a specific component that often fails? Do I need to order it from foretravel?
3) Is it possible that this is the result of how I chose to child-proof and cat-proof the parking brake, using a few small wire organizer clips? (See picture below). If I over tighten these clips, the brake is pulled out slightly farther than it would normally be at rest while in park. I've only been using this method for 3 weeks.
James, take it to NAPA and tell them what it's for, pretty sure they can match it. If not call FOT.
James, if it is the rear of the brake control button it is a Hobbs pressure switch 77040 and is a 10psi. Dump your air out of tanks and disconnect the wire clip and unscrew it from fitting. It should have a # on it but I am almost certain that is the # I gave you. As suggested NAPA can get it
JohnH
This is the 77040 one I mentioned
Industrial Pressure Sensors PRESSURE SWITCH D/C 5000 HARD BL: Amazon.com:... (http://www.amazon.com/Industrial-Pressure-Sensors-PRESSURE-SWITCH/dp/B0137IG8KC/ref=sr_1_fkmr0_1?ie=UTF8&qid=1482037783&sr=8-1-fkmr0&keywords=hobbs+switch+77040)
1. JohnH answered that one.
2. If air is only coming out of the pressure switch, then you just need to replace the switch.
3. I doubt your "cat-proof locking devices" had anything to do with the pressure switch failing. The actual parking brake air valve has a internal mechanical stop. Putting a little extra pressure on the knob in the "pulled-out" position should not hurt anything.
Replace the pressure switch. If leak is no longer evident, you are good to go. Have a beverage of your choice to celebrate!
Link below to a thread on rebuilding my parking brake valve. Your valve may be different, but should be similar:
Bendix PP-1 Repair Kit (http://www.foreforums.com/index.php?topic=27892.msg229649#msg229649)
Mine parking brake valve started leaking as well. Depending on which way you rotated the knob it would leak more or less. I checked out the kit Chuck used but wasn't sure if it was the right one for my 2001 version. I called FT to check on the part number I had. The OEM is no longer available the the current replacement was and it was about $30. I put in a new one. No leaks, saved the old one of course, someday it might get rebuilt.
You were exactly right, that was the number. A few tests suggest that was the only part leaking. I could get it faster on the internet than from Napa, so I am going to call FOT tomorrow to see if they can send it faster - otherwise I will order it online. The air lines were clean and came right off, but the pressure valve was fused solid and incredibly difficult, almost 2 hours of various sprays and tool combinations. Hope I didn't muck up the rest of the body.
Thanks all for the help.
Thought that would be it and when looking online for the part I found it from $25 to $40 so hope FT has it in stock and similar price for you.
The FT part # is P38163 I think according to my schematic if your build # is after 5458. Hope this helps.
JohnH
Pressure switch arrives tomorrow. Am I correct in saying that I should not use any sort of thread adhesive or tape?
The original part I removed did have some sort of unidentifiable adhesive assistant - it looked like a sloppy quick-fix and it was a nightmare to remove. But the air lines themselves have no adhesive/thread tape.
Seal with Rector Seal T plus 2
I use a Teflon sealer- no not the tape, the brush on kind. Used a lot by Plumbers.
JohnH
Fits like a glove and we are back in business. When the system first started re-pressurizing, air was leaking out of the front of the dash at the parking knob. Turned everything off at 30 psi, tightened the 1-1/8" flat washer about a 16th of a turn, and when I turned it all back on there was no more leak. But I don't really think it had anything to do with the tightening though - it felt more like there was a pressure seal that got created at around 30psi.
When we started looking for Foretravels, this forum and the helpful advice people seemed to be getting was a huge selling point. This problem would have taken me three weeks to solve (or some $$) from start to finish on my own - but with your help it took 3 days. Can't say how grateful we are. Thanks a ton. Definitely feeling like we made the right purchase decision. Hope to be able to pay it forward eventually.
As to using Teflon tape on air brake systems in a word don't. Use liquid only as small piece of tape can break off and get into the system. Loctite PST is good stuff. If the fitting is a compression fitting then pipe dope is not needed or desired as the seal is not made by the threads.
Keith
my quote"I use a Teflon sealer- no not the tape, the brush on kind"
Kieth, this pressure switch is screwed into unit and uses pipe threads, so using this brush on type would be fine as long as none gets into opening.
JohnH