HTALLEN
Fremont,CA
Senior Member
Joined: 10/17/2003
View Profile
 Offline
|
I have a 1997 Southwind on the P30 chassis....I want to change out the brake fluid... can anyone tell me the difference between DOT 3 DOT 4 and DOT 5 ? A mechanic who is going to help says use DOT 5, but I remember hearing that is a bad idea. What should I use ?
Thanks
Terry
1997 Southwind 32 VS,Banks,SafeTPlus,Bilsteins,Henderson Trac Bar
3 maniac poodles..Mozart,Ziggymonster,Nickolas
Honda Civic
|
Deen
Vancouver, WA
Senior Member
Joined: 12/07/2000
View Profile
|
I would use what the manufacturer of the MH says to use.
Deen - Vancouver, WA
'02 Dutch Star 4090 (41+', triple slide)
435/1200 ISC Cummins/Banks PowerPak
'08 Honda Civic/dolly
'05 Honda Odyssey/dolly
NRA Benefactor Life Member
FMCA f47302s, Life Member: Good Sam,
Newmar DP Owners Group
51st yr of RV'ing
|
bldrbuck
Boulder, Colorado
Senior Member
Joined: 02/11/2001
View Profile
|
I would replace with the one that is currently in the unit. A good auto supply store can tell you the specs on each.
|
Rangerdave
Austin Texas
Senior Member
Joined: 07/04/2008
View Profile
Offline
|
go with what the manual says. also a good note to make sure its a LMA approved fluid (low moisture activity). thats the only thing i use in all my vehicles, Castrol is the brand i use and its usually pretty hard to find and sometimes a bit pricy but worth it to me.
RD
2002 Gulf Stream Ultra Supreme-Demco Kaddy SS Toader Camry
2 peeps 2 poops and lots bbq!
No Fuss Flush
Ever stop to think, and forget to start again?
I feel like I'm diagonally parked in a parallel universe.
|
wagonmaster2
northcentral oklahoma
Senior Member
Joined: 02/18/2005
View Profile
|
I've read that DOT 3 & 4 will work in most vehicles, and will mix. I think DOT 4 is supposed to be a higher temp liquid. However, it seems like DOT 5 is completely different animal and should never be mixed with the other 2 and can deteriate hoses and cylinder cups if not made specifically for DOT 5. Maybe someone else on the forum has more info on these. But I would definitely know for sure what is going to be put in the master cylinder, don't trust what some mechanic might think. I've read that if the wrong fluid is used it can ruin every rubber part and hose on your brake system.
Wagonmaster2
|
|
|
Rangerdave
Austin Texas
Senior Member
Joined: 07/04/2008
View Profile
Offline
|
wagonmaster2 wrote:I've read that DOT 3 & 4 will work in most vehicles, and will mix. I think DOT 4 is supposed to be a higher temp liquid. However, it seems like DOT 5 is completely different animal and should never be mixed with the other 2 and can deteriate hoses and cylinder cups if not made specifically for DOT 5. Maybe someone else on the forum has more info on these. But I would definitely know for sure what is going to be put in the master cylinder, don't trust what some mechanic might think. I've read that if the wrong fluid is used it can ruin every rubber part and hose on your brake system.
Wagonmaster2
very correct!
"DOT 5 is for silicone brake fluid. Silicone brake fluid (DOT 5) should be avoided because it is not compatible with regular brake fluid, it is hard to pour without introducing bubbles and thus results in soft pedal feel, and moisture still gets into your system and will pool in low areas like your calipers and encourage rapid corrosion. STAY AWAY! "
source
RD
|
livingaboard
Everett wa
Senior Member
Joined: 09/06/2006
View Profile
Offline
|
Just in case you didn't believe the above posts, do not use silicone brake fluid in your rig. There is a DOT 5.1 non silicone brake fluid that you can use with DOT 3 or 4 but it will probably be hard finding it and I don't know that it has a higher boiling point or wet point than DOT 4.
Just use the DOT 4. It has a higher boiling point than DOT 3 and won't hurt anything. I use the synthetic. I believe it has a higher boiling point than the standard DOT 4.
Just remember, anything fluid that says silicone, which is used in racing applications, should not be used in your brake system.
Dave
Everett, WA
2000 Itasca Suncruiser 35U, F53 Triton V-10
Firestone air bags with Quad control air gauge
Pressure Pro
Banks Exhaust
|
RJCorazza
Maryland
Senior Member
Joined: 12/17/2005
View Profile
Offline
|
All good advice, except from your mechanic. NEVER use DOT5 silicone based brake fluid in a vehicle not designed for it. I use valvoline DOT4, but Ford Motorcraft DOT3 Heavy Duty is very good also (has a similar wet and dry boiling point as a DOT4 fluid). I do recall reading that DOT5.1 was not silicone based, but I am not familiar enough to comment further on that one.
|
SunflyerA
Andover, Minnesota USA
Senior Member
Joined: 01/08/2004
View Profile
Offline
|
Speed Bleeders
I used these on my F53....worked great....allows you to do it to do it alone.
sunflyer
2005 Fleetwood Excursion 39S
350 Cat
|
HTALLEN
Fremont,CA
Senior Member
Joined: 10/17/2003
View Profile
Offline
|
Guys, thanks for all the great info...I think I will go with DOT4 syn......
I thought I remembered something about not using DOT5, really glad I asked you all.
T
|
|
|
