Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 01-28-2023, 01:19 PM   #1
Junior Member
 
Join Date: Mar 2019
Posts: 3
E450 brake problems

Hi!
Ii am uk based and have owned a FR lexington since 2007
It's a e450 super duty with a V10 6.8 triton
Having problems with the braking system
Having lost a lot of brake fluid and not finding any signs as to where it has gone. everywhere is dry from the brake pedal to the rotors, pipes etc no signs
I have depleted the vacuum system and the brake pedal is staying hard. is it possible for the brake assist ( servo ) to be passing fluid if so where would it go. ?? And what short term damage would it cause
Any help would be greatly appreciated
John
Uk lexi is offline   Reply With Quote
Old 01-28-2023, 07:31 PM   #2
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,453
Quote:
Originally Posted by Uk lexi View Post
Hi!

Ii am uk based and have owned a FR lexington since 2007

It's a e450 super duty with a V10 6.8 triton

Having problems with the braking system

Having lost a lot of brake fluid and not finding any signs as to where it has gone. everywhere is dry from the brake pedal to the rotors, pipes etc no signs

I have depleted the vacuum system and the brake pedal is staying hard. is it possible for the brake assist ( servo ) to be passing fluid if so where would it go. ?? And what short term damage would it cause

Any help would be greatly appreciated

John
When brake fluid disappears with no visible signs it is usually a leak in the master cylinder where it joins the vacuum booster.

Two ways to diagnose. The hard way is to remove the master cylinder and look at it's rear where operating rod sticks out.

Another is far easier. Take a sheet of newsprint and roll it into a long, tight piece about the size of a long thick pipe cleaner.

Once you have this done remove the vacuum check valve on the booster can. It is the fitting where vacuum hose is attached and almost all check valves have a barbed tube that is pushed into a rubber grommet. With the check valve out use the tightly rolled newsprint as if it was a dipstick and probe ihe inside of the booster can's lower regions.

There should be NO brake fluid in this can and if the end of the newsprint comes out wet, master cylinder needs replacement.

Newsprint is preferred over regular paper as it will suck up liquids immediately and there will be no question if it's wet.

Good luck but based on your description that's the only place left for the fluid to go.

Sent from my SM-N950U1 using Forest River Forums mobile app
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)

"You only grow old when you run out of new things to do"

2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change)
TitanMike is offline   Reply With Quote
Old 01-29-2023, 10:59 AM   #3
Junior Member
 
Join Date: Mar 2019
Posts: 3
Hi thanks for the information will try and sort it out with your recommendation..
Thanks john
Uk lexi is offline   Reply With Quote
Old 01-29-2023, 06:11 PM   #4
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,453
Quote:
Originally Posted by Uk lexi View Post
Hi thanks for the information will try and sort it out with your recommendation..
Thanks john
Good luck and if you solve your problem come back and let us all know what you found.

Others with the same issue or question will benefit.
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)

"You only grow old when you run out of new things to do"

2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change)
TitanMike is offline   Reply With Quote
Old 01-29-2023, 06:19 PM   #5
Junior Member
 
Join Date: Mar 2021
Posts: 15
If it has a vacuum booster could be getting sucked in from the rear piston seal on the master cyl. If you remove all the vacuum from the booster wether you have a bad master cyl or not your pedal will be rock hard. Remove bolts from master cyl and pull it forward if it's wet there's your problem.
2021rvers is offline   Reply With Quote
Old 01-29-2023, 06:58 PM   #6
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,453
Quote:
Originally Posted by 2021rvers View Post
If it has a vacuum booster could be getting sucked in from the rear piston seal on the master cyl. If you remove all the vacuum from the booster wether you have a bad master cyl or not your pedal will be rock hard. Remove bolts from master cyl and pull it forward if it's wet there's your problem.
True, this also works but often the brake lines connected to the Master Cylinder, being rigid and usually with no "slack" make the "paper dipstick through the vacuum port" a lot quicker and easier.

In most cases where one has absolutely found zero leaks at calipers, wheel cylinders, flexible lines, proportioning/failure indicating valves, ABS controllers, and every inch of the steel brake lines, they just plan on replacing the master cylinder. Removing it usually just confirms it's bad.

Also, another indicator that the M/C is leaking into the booster is when divided M/C reservoir's rear portion is where the loss of brake fluid occurs.
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)

"You only grow old when you run out of new things to do"

2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change)
TitanMike is offline   Reply With Quote
Old 01-29-2023, 07:16 PM   #7
Senior Member
 
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 9,868
True, but...

Quote:
Originally Posted by 2021rvers View Post
If it has a vacuum booster could be getting sucked in from the rear piston seal on the master cyl. If you remove all the vacuum from the booster wether you have a bad master cyl or not your pedal will be rock hard. Remove bolts from master cyl and pull it forward if it's wet there's your problem.
True, but Post #2, posted 23 hours before yours, shows an easier way to detect the same problem.
__________________
Larry
"Everybody's RV is not like your RV."
"Always take pictures with the button on the right."
"Always bypass the water heater before opening the low-point drains."
Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
Larry-NC is online now   Reply With Quote
Reply

Tags
e450

Thread Tools
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


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 07:54 PM.