Brake Fluid Conversion

[John M.]

[Patrick H.]

Re: Brake Fluid Conversion

Pennzoil DOT4 is what most of us use for C6 clutch systems. I'd use the same for a brake system if desired.

DOT4 does have a higher boiling point, but if you're not autocrossing or doing high speed runs I doubt you'd ever know the difference.
You lose more due to the aging of it over time than in going with DOT4 vs 3.
Change it every few years with DOT3 and I think you'll be fine.

[Duke W.]

Re: Brake Fluid Conversion

DOT 4 is DOT 4... brand makes NO DIFFERENCE. Siphon or vacuum out the old fluid from the reservoirs. Use Q-tips and fresh fluid to clean any sludge out of the bottom of the reservoirs if they can be accessed. (Some can't due to internal baffling. In that case bleed that side of the system until the res. is nearly empty.)

Fill with fresh fluid and start bleeding with the SHORTEST circuit, which would be the LF then go RF, LR, RR. Do about six pumps at each corner, and run about a quart through the system. That will have you making the circuit at least three times, which will ensure a through flush.

I doubt if you need the higher DOT 4 boiling point, but DOT 4 may have better corrosion inhibitors, and I use it in all my cars.

Some cars have a separate system for ABS. I don't know about C4s, but the one car I have with ABS doesn't have a separate system and flushing the brake fluid is the same as a non ABS car.

Of course, you should flush the clutch hydraulic system in addition to the brake system.

Duke

[Mark E.]

Re: Brake Fluid Conversion

Also check the maintenance schedule in the owners manual. Flushing the brake fluid every two years regardless of mileage is typical.. 18 years is too long.

[Duke W.]

Re: Brake Fluid Conversion

There may be none. Unfortunately domestic manufacturers didn't recommend fluid changes in the past, and that's why brake systems could fail in as little as five years.

The German OEMs typically recommend flushing the system with new fluid every two years.

Once I started doing that on ALL my cars 30 years ago, I have never had to overhaul any brake system hydraulic components, and still have the same cars.

Duke