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Topic: Air Brake Leak (Read 917 times) previous topic - next topic

Air Brake Leak

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
w/ DW Erin, sons Gideon and Tobias, cats Oscar & Oliver
Fulltime 1999 U270 34' #5508

Re: Air Brake Leak

Reply #1
James, take it to NAPA and tell them what it's for, pretty sure they can match it. If not call FOT.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Air Brake Leak

Reply #2

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:...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Air Brake Leak

Reply #3
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
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Air Brake Leak

Reply #4
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.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Air Brake Leak

Reply #5
I am almost certain that is the # I gave you.

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.
James
w/ DW Erin, sons Gideon and Tobias, cats Oscar & Oliver
Fulltime 1999 U270 34' #5508

Re: Air Brake Leak

Reply #6
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
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Air Brake Leak

Reply #7
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.
James
w/ DW Erin, sons Gideon and Tobias, cats Oscar & Oliver
Fulltime 1999 U270 34' #5508

Re: Air Brake Leak

Reply #8
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
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Air Brake Leak

Reply #9
I use a Teflon sealer- no not the tape, the brush on kind. Used a lot by Plumbers.
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Air Brake Leak

Reply #10
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.
James
w/ DW Erin, sons Gideon and Tobias, cats Oscar & Oliver
Fulltime 1999 U270 34' #5508

Re: Air Brake Leak

Reply #11
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
Keith, Joyce & Smokey the Australian Cattle Dog
1995 U320 SE Extreme 40' WTBI Build # 4780, with a Honda CR-V hopefully still following behind.
Motorcade # 17030
FMCA # F422159

 

Re: Air Brake Leak

Reply #12
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
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.