Misc: Everything Else Problem Reverse Bleeding Disc Brakes

[CarlHungness]

What part swells with DOT 3 ? Should not happen ! I do know stories about old hoses growing shut by glycol so have to be changed in times. Not so with silicon, provided all components rustfree , no leaks to be expected ever with silicon, a bit higher viscosity too , they say. With poor bores in cylinders and all from dirt or rust no joy with either fluid definitely. But working on silicon systems is a lot nicer, does not strip paint when messing around a bit carelessly.

Vic

fresh restoration Ford Capri 2.3 with silicon in white container right side :
View attachment 55920

Goggle the Dot 3-4-5 brake fluids and you'll find the SAE did extensive tests on all, and the Dot 3 was the one that leaked the least as it has a tendency to 'swell' hoses whereas the Dot 5 can find its way out in the same circumstances. That's not to say Dot 5 is leaky. Extremely tidy looking engine compartment there, complimented by the glossy radiator tank.

 

[oexing]

So with DOT 3 you could wait for hoses to swell shut in time as with textile fabric in the material the hose cannot possibly swell wider ? The more I learn about glycol sh** the less I like it. But then, no need for learning that nasty stuff in my age. So again, anyone with Harley brakes experiences ? They obviously had silicon up to ABS times I guess. There must be lots of reports from them about troubles with silicon - or maybe not . . . .

Vic

 

[Russell Kemp]

Carl, fit some braided lines and pump some new fluid through using the tool that I posted and all will be fine. I did this on my Shadow and the brakes were as good as the Honda Fireblade that I owned at the time. If you have Dot 3 in it now then just replace with Dot 3.

 

[Bill Thomas]

That always made me Laugh,
In the 60s 70 s, Cars often had different make parts ,
Some Lockheed and another make on the SAME car !.

 

[Paul Coene]

DOT 5 Wiki Information from American Department of Transport.
Widely Known DOT5 and ABS never.

DOT 5[edit]​

DOT 5 is a silicone-based fluid and is separate from the series of DOT 2, 3, 4, 5.1. It is immiscible with water, and with other brake fluids, and must not be mixed with them. Systems can change fluid only after a complete system changeover, such as a total restoration.

It contains at least 70% by weight of a diorgano polysiloxane.[7] Unlike polyethylene glycol based fluids, DOT 5 is hydrophobic.[8] An advantage over other forms of brake fluid is that silicone has a more stable viscosity index over a wider temperature range. Another property is that it does not damage paint.[citation needed]

DOT 5 brake fluid is not compatible with anti-lock braking systems. DOT 5 fluid can aerate when the anti-lock brake system is activated. DOT 5 brake fluid absorbs a small amount of air requiring care when bleeding the system of air.[9]

One day, when I modified the brake system of my Buell, I called the nearest autopart-shop and asked them if they sold DOT 5 brake fluid. They did ! So I went there, and - it was to be expected - I found out they had the 5.1 but not the DOT 5. I even had to explain them what the difference was as they didn't have a clue. So, as both types should never be mixed, I always wondered who and why some very clever genius decided to call the glycol type DOT 5. Total confusion guaranteed !

 

[Speedtwin]

Move up to a higher boiling point fluid maybe D0T4 or 5.1 not worth the hassle of replacing hoses and seals for DOT5.