Do any HAMBers use DOT-5 brake fluid?

Do any HAMBers use DOT-5 brake fluid? I understand the text-book pros & cons compared to -3 & -4, but would like to hear some first-hand insight.

 

I look at DOT 5 the same way I look at synthetic motor oil. Cars worked fine for a hundred years before the shit was invented, why pay more for something you don't need????

 

Dot 3 & 4 will draw moisture into the fluid. For cars that sit for awhile or not drivin enough to keep the moisture adjitated(sp) and to keep it from settling at the bottom of the caliper where it will make rust pits. Dot 5 will not draw in moisture so if they sit alot the brakes will last longer.

 

doesnt take pait off either

 

Doesn't it also have a higher boiling point (like for race cars)???

 

All good points, but do YOU use -5? Would YOU use it again in your hot rod?

 

it's WAY past time for me to flush out my system,i'm gonna go dot 5.when i was in the army we changed over every vehicle that had hydraulic brakes to dot 5,they all worked just fine,and i do believe fewer brake jobs as a result.some people complain that the brakes feel a little softer,but they work just as good as before IMHO-george

 

Yes, I use it. You must completely get out all the dot 3-4 before putting in any dot 5 and another thing, if you use a brake light switch that is in the master or in the system some place and not an electrical one on the brake pedal, then use a sender switch out of a Harley. All the later model Harleys use dot 5. Dot 5 has been known to eat up some older style sender switches that are in the system. Also dot 5 will find any loose fittings and will leak easyer then dot 3-4.

 

10 years and 40,000 miles in my 32 roadster.
Mustang discs up front and Merc wagon drums in the rear.

Some mountain driving, lots of hard brake use on the way home. Kinda fun to roll on the brakes pretty firm at 60 mph and make the hard right turn off the highway to the side street where I live. (Provided no one is behind you.)

Topped off the M/C twice, added about a half inch fluid both times.

I was gonna run regular fluid and am glad I didn't because the unions joining the brake lines leaked and would have ruined the paint.
Lesson learned there was not to use brass unions.
Use steel ones instead.

 

Lionheart has a good point about the brake light switches.
Hydraulic switches in a silicon system will fail after a couple of months.
The failure noted as excessive pedal pressure to light the stoplights.
What happens is the silicon fluid ingresses by the seals and insulates the contacts electrically.
Best to use a mechanical switch if you can.

If Harley is having success with their hydraulic brake switch - and it sounds like they are - in a silicon system then that would be the way to go
I'm guessing a little pricey though.

 

Timely topic. We were discussing this today. I might just try it.

 

I had some in a '59 Chevy El Camino and didn't like it. I flushed it out and went back to -3 and it felt better. Up in the desert I don't have to worry about moisture too much.

 

It's all I've ever put in my '55 and it seems to be working just fine. The switch still works after at least 4,000 miles too, but they're only like $5 on ebay anyway.

 

From Wilwood's website:

"DOT 5 Silicon Fluid is not recommended. In addition to being easily aerated which leads to a spongy brake pedal, it is not hygroscopic, which permits moisture accumulation in the brake system, lowering the boiling point. Note: To maintain a high dry boiling point and maximum performance, change the brake fluid often, especially after high heat cycles."

 

I always taught that over a longer period of time (couple of months), DOT5 would absorb more water then DOT4.
You should only use DOT5 when you tend to flush your brake system on a regular basis (like race cars). Otherwise, go with DOT4.

 

I have heard you dont want to mix DOT 3-4 with 5 or it will turn into a jello like consistancy.

 

I first used DOT 5 in a 'stock '37 Chevy sedan I had in the early 80's. I replaced all rubber components with NEW parts (NOT NOS), including hoses, cups, etc. and flushed and blew out all the steel lines out with solvent, so they were ultra clean & dry. I had the car until the late 90's and never had a problem with it. When it was sold, it had the original brake light switch that I had installed in the 80's and the pedal was as hard as a 16 year old on his first date. I drove that car 2000-3000 miles a year and it sat for long periods during the winters, with no other maintenance. I now have had DOT 5 in my coupe (10 years) and my '55 Buick (6 years) and haven't had a bit of problems with any of them.
My 2¢