New brake system fluid

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DART66GT

DART66GT

62 Lancer GT - B Body 8 3/4
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I just finished bending my last brake line on the Lancer. Everything in the brake system is new. Every car I've ever had was dot 3. I've read a lot about the different fluids (there is a lot of misinformation out there) is there any advantage to dot 4 in a summer driver hopefully to be a 14 second car once the turbo goes in. I'm thinking staying with 3.0
 
Personally. DOT 5 is what I would use. Fully compatible with seals, etc and will not harm your paint. I switched over from DOT 3 in my 72 after flush and rear disc swap. Zero issues. Yours is fresh so better candidate.
 
Dot 3,4,5.1 attacks paint and is hygroscopic (absorbs moisture and will cause internal rust if old) DOT5 is silicone based and is paint safe but cannot be mixed. if you got all new brakes and have never been exposed to fluid, you can use DOT5. DOT5 has a higher compressability than DOTx so it could possibly feel a little spongy especially in a drum/drum system. DOT5.1 is probably the best to use. Highest boiling point, most compatible, most stable viscosity in low temps.
 
We swapped to Dot 5 after a Dot 3 leak caused paint peeling. Works like a charm zero issues. 67 cuda factory disc non power. Dot 6 does not peel paint or absorb moisture.
 
One problem with dot 5 I read is that it does not absorb moisture. (silicone base)
Any moisture that would seep in would pool in the system.

I'm converting my system to disk and did research in different Dot grades. Going to go Dot 4 or Dot 5.1. Both are glycol base
 
Ager said:
One problem with dot 5 I read is that it does not absorb moisture. (silicone base)
Any moisture that would seep in would pool in the system.

I'm converting my system to disk and did research in different Dot grades. Going to go Dot 4 or Dot 5.1. Both are glycol base
Click to expand...

I've run dot5 for over 10 years with no issue. Dot 3 will put moisture throughout the entire system. If that worried about moisture with dot 5 then bleed the brakes every spring. Should flush it right out if it's at the wheel cyls and calipers. So simple.
 
DOT 5.

With the amount of nice cars ive seen paint damage on due to a leak id never fill a new system with anything less that DOT 5.

Its a no brainer.
 
I've run DOT3 in everything I've owned since I've been driving. That's over 40 years. Never had an issue with anything. I'm not knocking any of the rest, simply relaying my experience.
 
There is a very samll number of these car that are built to the point they require anything more that dot 3. You really need to be road racing (on a track) to need it but the paint issue is what sells it for me.
 
Multiple opinions. Hard to decide? If the fear of a POSSIBLE leak causing paint blistering bothers you, go with DOT5. Otherwise, I would just use good old DOT3. I have never had a problem with it. You will want to flush out the brake system periodically since it tends to absorb moisture.
 
Its not the leak, its when someone who dont know better helps bleed the brakes, steps on the pedal and blows fluid everywhere.

Or someone setts the cap on the inner fender.

Or the use a rag to stop the drip off the bottle they just pored then set the rag on the fender.

Or the half open bottle they had in the trunk leaked out..

Don't get me wrong, my race car has DOT 3 in it but its a rust bucket with 4 different colors so the paint aint a big concern.

In customers cars with nice paint.

Hell yeah i push for DOT 5..
 
If you’re drag racing and happy with the DOT3, I say stick with it. If you’re road racing, step up to a DOT4, as it has a higher boiling point. Back in the day, before there was a DOT5, Castrol GT LMA was the hot setup.
Castrol GT LMA Brake Fluid 12614/12504
 
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