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guzzijim

Just received my MMM look at page 230 Rear over hang interesting points to consider!

1 Dynamic behaviour ie. A frames versus trailers.

2. 750 kg towed unbraked will extend stopping distance by 22%, so therefore a braked A frame set-up relying non servo assisted brakes efficieny say 30% will still add say 15% to stopping distance! thats a lot of extra feet in an emergency!

olley · Campsite DB Admin

Hi guzzijim Re: silicon brake fluid
I have never had anything to do with it but many people report a spongy pedal due to air entrainment.

You are also recommended to completly disassemble and clean all your brake components before refilling with silicon as dot 3&4 don't mix with it. which seems alot of work to me

Here's something I found on the net:

If silicone is introduced into an older brake system, the silicone will latch unto the sludge generated by gradual component deterioration and create a gelatin like goop which will attract more crud and eventually plug up metering orifices or cause pistons to stick. If you have already changed to DOT 5, don't compound your initial mistake and change back. Silicone is very tenacious stuff and you will never get it all out of your system. Just change the fluid regularly.
New developments
Since DOT 4 fluids were developed, it was recognized that borate ester based fluids offered the potential for boiling points beyond the 446F requirement, thus came the Super DOT 4 fluids - some covered by the DOT 5.1 designation - which exhibit a minimum dry boiling point of 500F (same as silicone, but different chemistry).
Additionally, a new fluid type based on silicon ester chemistry (not the same as silicon) has been developed that exhibits a minimum dry boiling point of 590F. It is miscible with DOT 3-4 fluids but has yet to see commercial usage.

Do any of the major manufacturers fit it as standard? BMW, Merc, Ford ect?

Olley

guzzijim

spongy pedal due to air entrainment

What ever fluid you use if there is air in the system either will cause same problem. At least silicon doesn't absorb water! I don't think it absorbs air, must say I've never tried to find out.
Have a new litre of silicon for tow car, was going to pump it through m/home first which has had silicon in system for two years. Never bothered to disassemble on last m/home had it in for 7years no probs. Silicon floats on top of traditional fluid so it easy to settle it out.

peedee