It has been 3 years with the Demco Dolly, time to flush the Brake fluid

[Joe Hogan]

After 23k miles and three years or so of use it is time to change the brake fluid. Typically I use a pressure tool to move this process along as I work alone. Not sure how I can flush this system solo. Any thoughts?

 

[Kevin D Pem]

Try this Dual Vacuum/Pressure Hand Pump Kit

 

[Joe Hogan]

Any thoughts as to brand of Dot 4 Fluid? Bosch ES16-32n might work or do I just go for the sale price item.? Don't care for STP or Castrol or Prestone... Maybe Lucas

 

[Kevin D Pem]

Any thoughts as to brand of Dot 4 Fluid? Bosch ES16-32n might work or do I just go for the sale price item.? Don't care for STP or Castrol or Prestone... Maybe Lucas

Synthetic in any brand will not absorb water.

 

[Joe Hogan]

Good point, especially since the Dolly is in Fla most of the year. I have considered Dot 5 (silicone-based brake fluid) but not sure if i want the hassle of purging the Dot 3 or Dot 4 (Glycol Ether/Borate Ester) and expense of Dot 5. From what I have read eliminating the brake system of the residual Glycol Ether/Borate Ester fluid can be quite involved.

Also there is a potential issue with DOT 5 fluid as it might not be compatible with brake components as noted here from an internet technical discussion.

"Additionally, there are some brake systems that may not work with silicone brake fluids because of their chemical composition. It's possible if you have some silicone rubber external components, things like your caliper piston boots, that a DOT5 brake fluid could actually break them down."

While the Dolly brake system is as basic as any, Dot 5 silicone may not be compatible with some of the existing brake components.

 

[Kevin D Pem]

Good point, especially since the Dolly is in Fla most of the year. I have considered Dot 5 (silicone-based brake fluid) but not sure if i want the hassle of purging the Dot 3 or Dot 4 (Glycol Ether/Borate Ester) and expense of Dot 5. From what I have read eliminating the brake system of the residual Glycol Ether/Borate Ester fluid can be quite involved.

Also there is a potential issue with DOT 5 fluid as it might not be compatible with brake components as noted here from an internet technical discussion.

"Additionally, there are some brake systems that may not work with silicone brake fluids because of their chemical composition. It's possible if you have some silicone rubber external components, things like your caliper piston boots, that a DOT5 brake fluid could actually break them down."

While the Dolly brake system is as basic as any, Dot 5 silicone may not be compatible with some of the existing brake components.

Ask Demco

 

[Joe Hogan]

Demco, Dot 3 or 4

 

[Joe Hogan]

Here is an interesting source of Brake Fluid data Brake Fluid Comparison Shopping

 

[Kevin D Pem]

Demco, Dot 3 or 4

Wet and Dry columns are with water and new. I started using dot 5 a long time ago, and yes I am mindful that dot 5 is not for ABS systems. My boat trailer surge brakes worked well with it for one reason it was my only choice. My vintage cars (Before ABS) were converted as soon as I knew there was dot 5.

Inert is the term for silicone. Meaning it will not react to the components in a brake system, It will gel with standard brake fluid. Unlike oil swelling seals or deteriorating tires. Silicone will not cause deterioration of rubber or silicone parts. Rubber parts are made using a process known as vulcanizing ( a process of heat and pressure). Silicone parts are made with a process known as catalytic reaction, that can not be reversed with heat or dilution.

In my opinion there is no other option than silicone brake fluid for non ABS systems.

 

[Joe Hogan]

Kevin, how did you get all the old brake fluid out of the system to install DOT 5? From what I have read it can be a tedious process short of a complete rebuild.