standup303
Well-Known Member
Just bought this new MC, can I use DOT 5? Replacing all the lines and hoses this weekend. I just don’t want a brake fluid that can eat my paint.
Can I use DOT 5 in this MC?
- Thread starter standup303
- Start date
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From everything I have seen yes.
The mixing is the issue. ( Some publications have said it is not an issue to mix but I wouldn't)
The mixing is the issue. ( Some publications have said it is not an issue to mix but I wouldn't)
el5dart
Well-Known Member
i wanted to use dot 5 in my dart when i had all new brake system but i wound up using dot 4 because of availability issues with the dot 5. i didn't want to be stranded somewhere and not be able to buy dot 5 at any parts store
I use it in a Triumph Tr6 with no issues. If you are swapping the whole system, that is the perfect time to do it.
I think the general consensus is that it is better for cars that don’t get driven much as it is not hygroscopic, so you dont have to worry about corrosion from water in the system.
I accidentally bought too much of it, so if you need some pm me & I will make you a deal.
I think the general consensus is that it is better for cars that don’t get driven much as it is not hygroscopic, so you dont have to worry about corrosion from water in the system.
I accidentally bought too much of it, so if you need some pm me & I will make you a deal.
Ironracer
Gearhead
I run it in the Ironhead drag bike, And it's the ticket for cars, as said above. Especially in high humidity areas ( like Here, lol)
The thing I have heard about it is if moisture gets into the system it tends to collect on a low spot. Rather then being dispersed into all the fluid.
Personally I'm not too worried if your system is properly sealed.
Personally I'm not too worried if your system is properly sealed.
When we put DOT 5 in due to the MC leaking and ruining paint, it mixed with DOT 3, no issues. Dad n I simply kept topping up with 5 while we bleed out the 3.
Ironracer
Gearhead
I have heard that the 5 don't mix in with the rubbers..
Zeros issues so far, 12 years and counting...give or take.
I havent checked fluid in over 4 years, that's how long mg its sat.I'll pop the lid off this weekend.
I havent checked fluid in over 4 years, that's how long mg its sat.I'll pop the lid off this weekend.
Ironracer
Gearhead
Cool Man! Just going by what I read... heck, I've been prescribed 2 of the same rescue inhalers, in the last week, from 2 different Dr's, both don't mix with my Beta Blocker... and the inhaler Raises yer BP and pulse! I just switch em up, time wise.. So maybe the book ain't always right! Lol
I looked into this issue and rebuilt my calipers and master with DOT 5 for assembly lube. Will be running the complete system on DOT 5. Dot 3, 4 and 5.1 absorb moisture from the air, where as DOT 5 (silicone based) does not.
Ironracer
Gearhead
That's why we don't use em on a Scoot!
No problems here either. Switch it in 2011
A lot of the brake fluid discussions remind me of the Freon discussions from the past. There were countless stories about how you couldn’t switch to R134 without the sky falling. As it turned out, as long as you followed a few basic instructions, everything was fine. I think it is the same here.
DOT 5 when I redid the braking system on the 64 Valiant. Zero issues.
New MC had that same warning label
New MC had that same warning label
Mopar44134
Well-Known Member
I run dot 5. Makes a big difference slowing it down at the end of the 1/4 mile with 4 drums and manual brakes.
C130 Chief
Mechanical Genius
No problem using DOT 5. Since you are replacing the master, you'll end up doing a system flush when you bleed. As for mixing, there's no problem just a lot of incorrect ballyhoo. Just another case of people believing BS over the boring old truth.
abodyjoe
Well-Known Member
if someone is worried about that then just bleed the brakes every spring and be done with it. i have been running dot 5 in our dart for close to 10 years now and haven't bled them or had any issues with them.
standup303
Well-Known Member
Thanks everyone. Installing the new lines and master today. Hoping to have the system fully bled by end of the weekend.
BillGrissom
Well-Known Member
Sure. I use DOT 5 silicone in most of my vehicles. No seal compatibility issues, indeed silicone is more benign. I read that some 1950's British cars required it since glycol fluids (DOT 3, 4, 5.1) attacked the seals. Crazy stories spread by auto parts guys about "if touches any glycol bad things happen". Absurd. An anal engineer decided to try that and left the two fluids in a bottle for a year. No reactions and totally immiscible. The fluid may turn yellow after years. That is not rust, but rather the blue dye changes color over time. People who fret about water drops settling to cause hidden corrosion should worry the same about dripping water into their power steering reservoir. Don't. But, if a water drop got in the silicone, I doubt it would cause corrosion since the silicon fluid keeps oxygen away. More compressibility is a fuss, but maybe 10% more and perhaps negligible compared with flex in rubber hoses and seals. Just insure no air bubbles. Pour the fluid down the side of a funnel to not blurb in air. If you drop the jug, wait a day for the air bubbles to come out. The U.S. military used to spec silicone as "BFS" (brake fluid silicone) since no corrosion nor need for regular flushing. Then some officer pushed a change to glycol fluid, supposedly since "more available" but "cheaper" is the likely reason. In a pinch, you could always add glycol fluid and nothing would happen other than now it can absorb moisture to cause corrosion, so the military logic seems specious. Anyway, harder to source now that surplus mil sources dried up (I bought several gallons years ago). But, many motorcycles use it, so can always buy it by the pint (pricier).
Finally, "not for ABS" is on DOT 5 bottles, which A-body owners need not fret. That has been questioned. My guess is simply "never qualified" so a lawyerly disclaimer. I put it in my 1996 ABS Plymouth just to see and it pulses the same as it did on wet roads, as best I can judge, and still stops and steers fine. There are now glycol fluids which meet the higher DOT 5 rating. They are assigned DOT 5.1 to not confuse w/ silicone, but I'm sure they do.
Finally, "not for ABS" is on DOT 5 bottles, which A-body owners need not fret. That has been questioned. My guess is simply "never qualified" so a lawyerly disclaimer. I put it in my 1996 ABS Plymouth just to see and it pulses the same as it did on wet roads, as best I can judge, and still stops and steers fine. There are now glycol fluids which meet the higher DOT 5 rating. They are assigned DOT 5.1 to not confuse w/ silicone, but I'm sure they do.
C130 Chief
Mechanical Genius
British, and many European cars had natural rubber seals and required DOT4 before 1968 or so. After that market pressure caused just about all manufacturers to use DOT3 compatible hydraulics. Most new rebuild kits will do fine with any fluid just like carb kits since the mid 80's are ethanol compatible.
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