RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > MH-General Discussions & Problems
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 07-08-2019, 10:27 AM   #1
Senior Member
 
Country Coach Owners Club
Join Date: Aug 2017
Location: Fort Smith, AR
Posts: 267
DOT brake fitting failure at 60mph

The brass elbow came apart while traveling 60 mph on I29 near Omaha. The brakes locked the right rear Tag an wore it through in seconds. My wife managed to pull to the shoulder where we waited (1 foot from the white line) 7 hours for Progressive pro roadside assistance. (press
You see in the attached picture the 1/2 npt part came out of the elbow part. I do not see what held them together. It just slips in and out. there is an Oring in the elbow but i see no mechanical retention feature that failed. Perhaps the failed portion disappeared.
You can see on the elbow a symbol which i guess represents the manufacturer's logo. I would very much like to see and understand the feature that held it in and failed.
any help?
Attached Thumbnails
Click image for larger version

Name:	failed elbow.JPG
Views:	16
Size:	66.4 KB
ID:	252557   Click image for larger version

Name:	failed elbow2.JPG
Views:	16
Size:	28.8 KB
ID:	252559  

__________________

__________________
Wsmcycle
2005 Allure 470 Siskiyou
BMW R1200RTLC
wsmcycle is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-08-2019, 10:46 AM   #2
Senior Member
 
CountryB's Avatar
 
Monaco Owners Club
Join Date: Aug 2017
Location: Orlando, Florida
Posts: 3,902
I'm not a fan of those Push-to-Connect fittings because the o-ring will eventually leak and it can't be replaced. Those P-T-C fittings are only good for assembly line workers. IMO

The P-T-C fittings (if made by reputable company like Parker) are pretty robust. I have not seen or heard of one coming apart like yours. But since those fittings have the "extra machining" (for the swivel and o-ring) it adds an additional point of failure.

Of course any fitting can fail. I always replace the P-T-C fittings with a standard DOT air-brake compression fitting when I have to replace one for leaking.

I suppose it is a good idea to go under the coach during your annual inspection and grab/wiggle all the brake fittings to check for any pending failures.

P-T-C fittings on top, and standard compression fittings in the middle and bottom of photo.
Attached Thumbnails
Click image for larger version

Name:	Push-To_connect fitting.JPG
Views:	12
Size:	142.1 KB
ID:	252565  
__________________

__________________
Mike -----2005 Beaver Patriot Thunder CAT C13 525HP, 42-ft Tag, with HydraLift
**Beaver Chassis Info/Types https://1drv.ms/f/s!AtvAXw_lfqbToxXYREK9YdBP08Jn
**Wiring Diagrams (1984-2009):https://1drv.ms/f/s!AtvAXw_lfqbTm0WTuuNqpn9a8hCh
CountryB is online now   Reply With Quote
Old 07-08-2019, 02:22 PM   #3
Senior Member
 
Country Coach Owners Club
Join Date: Aug 2017
Location: Fort Smith, AR
Posts: 267
the push to connect feature end is not the one that failed. the failure is on the NPT end.
__________________
Wsmcycle
2005 Allure 470 Siskiyou
BMW R1200RTLC
wsmcycle is offline   Reply With Quote
Old 07-08-2019, 04:34 PM   #4
Senior Member
 
CountryB's Avatar
 
Monaco Owners Club
Join Date: Aug 2017
Location: Orlando, Florida
Posts: 3,902
But it is the same fitting.
A P-T-C swivel fitting has two o-rings inside and a gripper to hold the hose, so it has more parts to fail than a standard compression fitting.

But they lasted 14 years (at least on my coach - you didn't say the age of your coach) before some started leaking, so if you want to use the style again I think you will be fine for the rest of the coach's life.

good luck
__________________
Mike -----2005 Beaver Patriot Thunder CAT C13 525HP, 42-ft Tag, with HydraLift
**Beaver Chassis Info/Types https://1drv.ms/f/s!AtvAXw_lfqbToxXYREK9YdBP08Jn
**Wiring Diagrams (1984-2009):https://1drv.ms/f/s!AtvAXw_lfqbTm0WTuuNqpn9a8hCh
CountryB is online now   Reply With Quote
Old 07-09-2019, 09:38 AM   #5
Senior Member
 
757driver's Avatar


 
Entegra Owners Club
Join Date: Jun 2004
Location: Cambridge, Ontario
Posts: 3,654
Glad you found the problem. I am curious, what caused your right tag wheel to lock up?
__________________
Don & Gerri
2014 Entegra Anthem 44B
2014 Honda CRV Touring

1100W Solar, 1200AH LiFePO4 FMCA F443497
757driver is offline   Reply With Quote
Old 07-10-2019, 03:52 PM   #6
Senior Member
 
Country Coach Owners Club
Join Date: Aug 2017
Location: Fort Smith, AR
Posts: 267
brakes on an air system are clamped down by springs. When you press on the brake, air is let off at the wheel cylinders and the springs clamp the brake according to the remaining air pressure. Let up on the brake and the increased air pressure opens the springs to allow rotation. When the Tag air line came apart, the air holding the tag brake escaped first and the springs clamped on the brakes. You wont believe what that did to the NEW 550$ tag. I will attach a pic.
Attached Thumbnails
Click image for larger version

Name:	tag failure.JPG
Views:	20
Size:	107.9 KB
ID:	252841  
__________________
Wsmcycle
2005 Allure 470 Siskiyou
BMW R1200RTLC
wsmcycle is offline   Reply With Quote
Old 07-10-2019, 04:05 PM   #7
Senior Member
 
757driver's Avatar


 
Entegra Owners Club
Join Date: Jun 2004
Location: Cambridge, Ontario
Posts: 3,654
Quote:
Originally Posted by wsmcycle View Post
brakes on an air system are clamped down by springs. When you press on the brake, air is let off at the wheel cylinders and the springs clamp the brake according to the remaining air pressure. Let up on the brake and the increased air pressure opens the springs to allow rotation. When the Tag air line came apart, the air holding the tag brake escaped first and the springs clamped on the brakes. You wont believe what that did to the NEW 550$ tag. I will attach a pic.
I see. Thought the spring brake was usually on the drive axle and not the tag axle. I guess yours is different.
__________________
Don & Gerri
2014 Entegra Anthem 44B
2014 Honda CRV Touring

1100W Solar, 1200AH LiFePO4 FMCA F443497
757driver is offline   Reply With Quote
Old 07-10-2019, 04:11 PM   #8
Senior Member
 
Join Date: Jul 2014
Posts: 18,061
Your explanation of how air brakes work is not correct.

Air pressure applies the brakes, to all wheels, when you step on the brake pedal.

Rear brakes ( typically only the drive axle ) have dual chambers with spring sections that apply the brakes when air pressure is lost or the parking brake is applied.
twinboat is online now   Reply With Quote
Old 07-10-2019, 04:31 PM   #9
Senior Member
 
JBDISCOVERY's Avatar
 
Join Date: Mar 2011
Posts: 547
Twinboat is correct. Pressing on the brake pedal applies air pressure to the brake cylinders to stop the coach. This is the service brake system.
If the air pressure drops out of the system, the springs clamp the brake shoes to the brake drums.
Just like when you park your couch, pull the yellow brake valve which drops the air pressure out of the system to set the brakes for parking.
Great system.
Regards,
JimB
JBDISCOVERY is offline   Reply With Quote
Old 07-10-2019, 05:38 PM   #10
Senior Member
 
richard5933's Avatar
 
Join Date: May 2019
Posts: 429
Did the brakes apply to your drives as well? I'm wondering if the tag locked up and not the drive axle because it's carrying much less weight than the drive.
__________________
Richard
1974 GMC 4108 - Custom Coach Conversion
richard5933 is online now   Reply With Quote
Old 07-15-2019, 04:32 PM   #11
Senior Member
 
Country Coach Owners Club
Join Date: Aug 2017
Location: Fort Smith, AR
Posts: 267
I am embarrassed by my ignorance. I am glad to have been straightened out.
The failed fitting was part of the right-side tag brake. I do not know why the other brakes did not clamp but the tag sure did.
thanks
__________________
Wsmcycle
2005 Allure 470 Siskiyou
BMW R1200RTLC
wsmcycle is offline   Reply With Quote
Old 07-15-2019, 04:39 PM   #12
Senior Member
 
Country Coach Owners Club
Join Date: Aug 2017
Location: Fort Smith, AR
Posts: 267
My original question was directed at the failure of the swivel joint on the NPT end, not PTC female on the opposite end. I can appreciate the disdain for the PTC end but that end did not fail. what was the design of the swivel joint? any drawings available?
__________________

__________________
Wsmcycle
2005 Allure 470 Siskiyou
BMW R1200RTLC
wsmcycle is offline   Reply With Quote
Reply

Tags
brake



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to back a trailer at 60MPH allendp Texas Boomers 3 02-04-2016 04:48 PM
60mph and 2500 rpm Pepper2 Ford Motorhome Chassis Forum 14 09-04-2014 09:52 AM
Irritating tone over 60mph Huberman Class A Motorhome Discussions 16 09-11-2011 12:35 PM
Front blowout at 60mph, curious what happens? billsmax Monaco Owner's Forum 27 08-25-2011 10:29 AM
Who Has Had Their A&E Awning Unravel AT 60MPH? Lockman MH-General Discussions & Problems 14 05-18-2005 04:27 AM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:41 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.