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 04-04-2014, 03:28 PM   #1
Senior Member
 
ronspradley's Avatar


 
Gulf Streamers Club
Join Date: Mar 2011
Location: Central Texas
Posts: 1,622
Brake Fluid Flush, Synthetic?

I am going to flush the brake fluid in my 93 Gulfstream MH. Should I use synthetic? It is not supposed to absorb water and that is the problem with regular fluid. This MH does not get used as much as it should and sits for much of the year. Do not think it matters, but it has discs front and drums rear, air over hydraulic.

Thanks for the input.

ronspradley

.
__________________

__________________
1993 Gulfstream Sun Voyager DP 30'
200 HP Cummins B5.9, 4sp Allison AT542
Toad 1998 Honda CRV, 2006 Honda CRV
Life's too short to drink cheap beer.
ronspradley 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 04-04-2014, 04:40 PM   #2
Senior Member
 
R2Home's Avatar
 
Join Date: Mar 2012
Location: Palmer Ak
Posts: 1,124
Years ago when I was working on vehicles, we were informed NOT to mix the two different types of brake fluid. If you are going to rebuild the whole system, drain all of the fluids and put new fluid in the system you might be OK.
No matter the fluid that is used, the hydraulic bakes system should be flushed to keep it working properly. It might be possible that the tow fluid can be mixed but lets hear from those that are currently in the business.
__________________

__________________
2009 38' Diplomat
CSM- retired, wife as co-pilot
Reka & Ali providing security (our 2 labs)
R2Home is offline   Reply With Quote
Old 04-04-2014, 07:29 PM   #3
Senior Member
 
scenic route's Avatar
 
Join Date: Jan 2010
Posts: 1,767
DOT 3 & 4 are designed to be hygroscopic(suspends the moisture it comes in contact with). With variations in temperature, moisture will always be a problem for brake systems. Todays brake fluids suspend this moisture and also contains corrosion inhibitors that help protect system components. That is why the experts recommend flushing brake fluid every couple of years. Mixing is not recommended.
__________________
Jan and Bob

RIP 'Squeaky'
scenic route is offline   Reply With Quote
Old 04-05-2014, 08:02 AM   #4
Senior Member
 
ronspradley's Avatar


 
Gulf Streamers Club
Join Date: Mar 2011
Location: Central Texas
Posts: 1,622
I do not want to mix the regular brake fluid with synthetic, I want to flush out the old, and replace with synthetic. Is that recommended?

ronspradley

.
__________________
1993 Gulfstream Sun Voyager DP 30'
200 HP Cummins B5.9, 4sp Allison AT542
Toad 1998 Honda CRV, 2006 Honda CRV
Life's too short to drink cheap beer.
ronspradley is offline   Reply With Quote
Old 04-05-2014, 03:24 PM   #5
Senior Member
 
scenic route's Avatar
 
Join Date: Jan 2010
Posts: 1,767
Ron, I understand that Prestone makes a DOT 4 synthetic but not sure what is required for a proper flush. Maybe a call to Prestone would be in order for the straight story.

Manufacturer: Prestone Products Corp. Div., Honeywell International, Inc. Address: 39 Old Ridgebury Road City: Danbury State: CT Zip Code: 06811 Telephone Number: 203-830-7800 Fax Number: 203-830-7904 Toll Free Number: 800-890-2075
__________________
Jan and Bob

RIP 'Squeaky'
scenic route is offline   Reply With Quote
Old 04-05-2014, 07:02 PM   #6
Senior Member
 
Nick-B's Avatar
 
Forest River Owners Club
Ford Super Duty Owner
Join Date: Aug 2009
Location: Vaughn, WA
Posts: 1,364
Let's get some terminology straight.
First, ALL brake fluid is synthetic. Don't let container labeling confuse the issue.
I think what is meant here is the difference between silicone DOT5 and conventional DOT3 & 4 fluid. Definitely don't mix those. DOT3 and 4 are compatible and the main difference is 4 has a higher boiling point, but only when it is fresh and not contaminated with moisture. Once it absorbs some moisture it has a lower boiling point than 3.
Don't use DOT5. It is for racing applications only.
If you want to use DOT4 just do a normal fluid flush. A trace of DOT3 won't hurt anything.
__________________
Nick
1995 Coachmen Santara 360MB 36' w/slide.
Ford F53/460 chassis, 1997 Jeep Grand Cherokee "toad"
Nick-B is offline   Reply With Quote
Old 04-06-2014, 09:44 AM   #7
Senior Member
 
Join Date: Nov 2005
Posts: 3,332
You should stick with either DOT3 or DOT4 fluid. DOT5.0 is a silicone based fluid that is not compatible with the rubber components in your system. There's also DOT5.1 which is used on newer vehicles that isn't silicone based, but I'm not sure whether it's compatible with the older rubber components.

Contrary to popular belief the brake system isn't totally sealed. The cover on the reservoir isn't air tight. Moisture will enter the system through the reservoir and dissipate through the fluid. The DOT3 and 4 fluids are designed to hold moisture in suspension. If they didn't the water would accumulate at the low points in the system and freeze in cold weather rendering the brakes useless. In warmer weather the water will remain at the low points and cause rust and/or corrosion.

While fluid containing moisture will boil at lower temperatures it will continue to work until it gets saturated. Saturation is considered to be when the volume of water in the fluid reaches the 3% range. This usually doesn't happen for several years. That's why the manufacturers recommend changing the fluid and flushing the system every 2 years.
__________________
Hikerdogs
2013 Adventurer 32H
Hikerdogs is offline   Reply With Quote
Old 04-06-2014, 11:35 AM   #8
Senior Member
 
ronspradley's Avatar


 
Gulf Streamers Club
Join Date: Mar 2011
Location: Central Texas
Posts: 1,622
Thanks for the responses. After reading here and elsewhere, I have decided to just flush and re-fill with DOT4 fluid. Recommendations I was reading suggested only switching to synthetic silicone based fluid when doing a complete re-build, replacing components and seals. Not doing that at this time.

ronspradley

.
__________________

__________________
1993 Gulfstream Sun Voyager DP 30'
200 HP Cummins B5.9, 4sp Allison AT542
Toad 1998 Honda CRV, 2006 Honda CRV
Life's too short to drink cheap beer.
ronspradley is offline   Reply With Quote
Reply

Tags
brake, fluid



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
Okay ... I SOLVED THE AUTO PARK BRAKE PROBLEM! JerryPeck Workhorse and Chevrolet Chassis Motorhome Forum 144 10-03-2017 11:45 PM
SMI Air Force One versus US Gear Unified Brake System rvMadness Toads and Motorhome Related Towing 23 06-15-2015 10:58 PM
Low Air presure - Park Brake iamduane Alpine Coach Owner's Forum 15 05-07-2014 05:49 PM
Time to flush my brake lines. How much fluid? jprisbe Ford Motorhome Chassis Forum 14 04-06-2014 06:42 AM
Hydraulic brake fluid RanchoT Class A Motorhome Discussions 2 08-17-2013 11:54 AM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 01:18 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.