Synthetic Brake Fluid

Boelt63A · Post by **Boelt63A** » Fri Sep 07, 2007 8:18 pm

Any thoughts on replacing with
synthetic brake fluid?

lindenengineering · Post by **lindenengineering** » Fri Sep 07, 2007 10:09 pm

Chuck
In short don't do it!
Synthetic fluid can have adverse effects upon some brake seal materials; Besides it can also react to the mineral fluid that is remaining within the system.

You may also find that the brakes will feel a little spongier than before the change over.

Often used in Mil applications due to the infrequent use of some equipment and hydroscopic reaction of mineral fluid, the use of silicon fluid is sometimes prefered. The silicon fluid obviously in these circumstances is preference and its sponginess is a valid trade off in Mil operations to water settling in the brakes over time.

For us ordinary road users where brake reaction time is paramount I suggest the common old Dot 4 works just fine.
Dennis

Boelt63A · Post by **Boelt63A** » Sat Sep 08, 2007 5:17 am

Thanks Dennis,

I have a friend who is recomending synthetic fluid, as I am about to rebuild the whole system on the 712. He mentioned the spongy feeling, but I wasn't sure about the benefits synthetics might bring, and I was worried about the suitability of the synthetic fluid in the pinz.

Chuck

lindenengineering · Post by **lindenengineering** » Sat Sep 08, 2007 8:33 am

Chuck
The benefits are that you don't have to flush every two years or so to purge the system of moisture.

The fluid is also more stable and much less likely to alter its chem' make up due to heat/oxidation etc.

My question is after all that rebuilding what are the ramifications if you find the brakes don't work so well??? Strip it all out again, purge out ALL the fluid and rebuild with Dot4.
Seems like alot of work and money to conduct an experiment for a small arguable benefit (should one exist?)

You could buy alot of beer for the cost of the seal kits yah know. What's that addage:- If it ain't broke don't fix it--
Cheers
Dennis

pinzinator · Post by **pinzinator** » Sat Sep 08, 2007 8:36 am

Dennis, correct me if I'm wrong, but synthetic and silicone are two different brake fluids. I thought synthetic is compatible with DOT 3 systems, whereas if you go with silicone (DOT 5) you have to drain the entire system first.

lindenengineering · Post by **lindenengineering** » Sat Sep 08, 2007 9:03 am

You are right.
However not all these fluids are created equal as I see/experienced it.
Sure all the manufacturers claim its compatibility, but they have tested it in vehicles commonplace in the markertplace.

The Pinzgauer due to its age, questionable history (having changed hands several times at least), and you are out there in a grey area.

Brakes are not a thing to be experimented with especially when the regular fluids do a nice job. Besides its alot of hard work to fix if it originally wasn't broken.
Maybe I see it all a bit different as a pro in this business. If I used such a fluid in my customers' vehicles and there was a failure it's my neck on the line!
Dennis (I'll play it safe)