Cleaning DOT5 out of my brake lines?

[Nicks67GTO]

I'm about to swap brakes on my GTO. I have a new master cylinder, proportioning valve and a brand new brake kit ready to go on this car. The problem is that I used DOT5 fluid in my current kit. Everything is getting replaced but the hardlines and they are only 2 years old so I would hate to toss them and buy new stuff. does anyone have any tips on cleaning out the old lines? Can I just blow them out with compressed air? Do I need to run solvent down them?

[camrat68]

Why can't you use Dot 5 on the new set-up?

I ask because I currently have Dot 5 in my Camaro and am about to switch from a master power disc/drum set-up to a Wilwood 4 wheel disc set-up.

thanks,
Jim

[a67]

Need to use an alcohol based solvent to clean out the lines. So either 91% isopropyl or denatured alcohol will do the trick.

Bob.

[parsonsj]

Why can't you use Dot 5 on the new set-up?

You can, but DOT 5 fluid is designed for show cars, museum pieces, etc. For any sort of enthusiast use, motorsports, or just driving it more than once a month, you should be using DOT 3, 4, or 5.1.

http://www.superchevy.com/technical/.../0509sc_fluid/

[camrat68]

Excellent information!
Thank you.
Jim

[Rifleman_Racing]

As stated get a gallon of alcohol and bleed that through till you see it coming out for a little while. Popping the pistons out of the caliper will greatly help speed it up, as a lot of it stays in the caliper during bleeding. Once you bleed it through with alcohol get a good quantity of quality DOT 3 or 5.1 and bleed though for a while.

DO NOT blow it out with compressed air, as you will load up the lines with water, which will be very hard to get out.

[MonzaRacer]

I just used regular non chlorinated brake clean, remove prop valve and such. I have even had luck in cleaning rubber hoses.
I even pulled master cylinder and calipers apart, then reassembled after cleaning.
BUT I have used regular spray brake clean when people contaminated system with oil or power steering fluid.

[Skip Fix]

Many motorcycles use silicone based fluid, our military uses silicone DOT 5. Bet Humvees in combat stress brakes as much as any of us would. I know many guys that use it and have no spongy pedal. I've had it in my 78 TA for 25 years no spongy feel autocrossing or shutting it down from 125mph at the drag strip to make the first turn around. I think it is a big reason the rear ratchet calipers on it have not locked up as most do with glycol based products.

[icemanrd19]

We used dot5 to bleed my brakes and it has zero run time. I want to switch to dot 3 or 4 brake fluid. Can i just open up my bleeders and pour in dot4 until its all gone?

[firecatwilson]

I've heard DOT 5 is a Mother %$#^ to get rid of/clean out... virtually impossible some say. I'm staying with my old school DOT 3.

[MonzaRacer]

Again use brake clean and compressed air then use dot 4or5.1 for the higher boiling point.

[Arctic_Ragtop]

From what I have read, when the Dot 3, 4, 5.1 comes in contact with any bit of the DOT 5 it can form a Jello like substance that has the potential to cause an unsafe braking environment. I upgraded the front drums on my '65 to disc and ran all new hardlines last year, and ran Dot 5, thinking that it would be better because it wouldn't eat the paint if it came on contact. I must have spent $100 on brake fluid and hours on hours trying to get the god damned thing bled....I finally got it to bleed but the pedal never felt right, so I looked into going back to Dot 4 and realized it wasn't that easy. I have decided on the 4-wheel Disc setup that I should have went with in the first place, I will be running new hard lines, a new master and Dot 4 with the new set up. I would hate to find out the hard way that Dot 4 and Dot 5 are in fact not compatible. I'm sure its possible to clean brake lines, but in my case, the new hard lines I ran last year didn't fit quite right so I will do it again and do it right and make sure to run Dot 4 this time.

[LS6 Tommy]

Gotta clean the snot out of it. When they mix things don't go well. There's also reasons why most racing organizations do not allow DOT 5.

Tommy