Silicone Brake Fluid Questions

[SFM6S087]

What's your preferred brand of silicone (DOT 5) brake fluid? Or are they all pretty much the same?

Where do you buy yours? I like to support the local stores, but no one seems to have DOT 5 on the shelf.

Please save your comments about silicone vs. other types for another topic. My car already has silicone and it's working fine for my limited driving purposes.

Thanks,
Steve

[sg66]

Autozone or Advanced Auto usually stock it. Motor Medic was the last brand I picked up. I consider DOT5 silicone to be equal regardless of brand but that's just my opinion

[vtgt500]

There is a chain of farm supply stores near me, Runnings.  They sell Motor Medic for $7.00 a pint.  Am using it in all 5 of my vehicles.

[OldGuy]

I believe that all DOT 5 fluids are compatible with other DOT 5 fluids so mixing one brand with another is not an issue.

I don't know were "local" is for you and I don't know who you tried to purchase your fluid from but you can get DOT 5 fluids from any number of on-line entities, such as E bay, Summit racing, Amazon, etc. You can use Walmart.com as a purchase source and have your product shipped to your local store, where you can pick it up and shipping is free. I'm sure you can also get it from your local Harley dealer. Just potential sources.

Be sure NOT to order DOT 5.1 which is NOT the same as DOT 5 nor is it compatible with DOT 5.

I hope this info. helps.

Frank

[98SVT - was 06GT]

Heard silicone fluids don't absorb moisture which allows water to pool and corrode in the lowest part of the system. Regular fluid is hydroscopic so it will hold the moisture in suspension - until it gets hot enough to boil it out.

[sg66]

Regular fluid is hydroscopic so it will hold the moisture in suspension - until it gets hot enough to boil it out.

Don't want to go deep into this rat hole as OP is only looking for DOt 5 but...to heat the fluid to boiling point would happen in the caliper and where would that steam go?

[mark p]

I am in the process of some work that requires new fluid for both brakes and clutch... have been using DOT5 for about 30 years.
Tried a couple of local parts stores (nothing)... so went to the interweb. Found that Motor Medic as noted, and bought 2 quarts.

[SFM6S087]

Thanks for all the helpful replies!

It sounds like the specific brand doesn't matter so I tried finding ANY DOT-5 on the shelf locally. No go. Tried AutoZone, Advance Auto, O'Reilly, and Walmart. One even listed Motor Medic DOT-5 in stock, but there was none when I got there, and the manager said they just don't stock it any more.

I got tired of chasing my tail and just ordered a couple of quarts from Virginia Classic Mustang.

Thanks again for sharing your knowledge & experience with me.

Steve

[CSX 4133]

Try Motul 660, it's a DOT 4 with a very high wet/dry rating that exceeds most DOT 5's.

https://www.pegasusautoracing.com/productselection.asp?Product=MT660&utm_source=google&utm_medium=cpc&utm_campaign=MT660&gclid=EAIaIQobChMImMG5q_nY3AIVgkOGCh3gtAmvEAQYBSABEgKYM_D_BwE

[Doug C]

It's been my experience that Amazon might be the place to look as well.

[Bob Gaines]

It is prudent to point out to those that might happen upon this thread in the future that when you convert over to Dot 5 it is more then just adding the fluid .The entire brake system has to be flushed with solvent to get rid of any conventional brake fluid. Best to do when all new components because the dot 5 will not mix with conventional brake fluids and if it comes in contact with any remnants it will gel and you run the risk of clogging up the system . Even wheel cylinders and brake calipers need to be assembled with the DOT 5. Typically when a rebuilder lubricates the rubber seals during assembly they will use conventional brake fluid unless alerted otherwise.

[Doug C]

It is prudent to point out to those that might happen upon this thread in the future that when you convert over to Dot 5 it is more then just adding the fluid .The entire brake system has to be flushed with solvent to get rid of any conventional brake fluid. Best to do when all new components because the dot 5 will not mix with conventional brake fluids and if it comes in contact with any remnants it will gel and you run the risk of clogging up the system . Even wheel cylinders and brake calipers need to be assembled with the DOT 5. Typically when a rebuilder lubricates the rubber seals during assembly they will use conventional brake fluid unless alerted otherwise.

Bob, as usual great advice and guidance.  I  wonder how many times you (and a few others out there) have saved Shelby owners butts with your keeping us honest.  Thanks again.

[Don Johnston]

Bob's answer is correct.  I used silicone brake fluid for many years to avoid moisture absorption, first in my '37 Packard, and later in the '66 GT350.  Great for non-track use if keeping the car mostly in storage.  But when it comes to regular driving, change and purge the entire breaking system before switching to non-silicone fluid.  The silicone fluid never gave the same fluid grabbing power response as non-silicone. 

[vtgt500]

Extended, first hand experience is always a consideration.  I've used DOT 5 exclusively in all my vehicles for over 25 years.  My late model BMW with sophisticated traction control and ABS works flawlessly.  No perceivable compromise in performance.  In my Impreza RS brake function upon system overhaul was noticeably improved.  On my '68 GT500 where storage corrosion is the primary concern, I have no worries.  Your mileage may vary.

[shelbymann1970]

last 3 full restos I did were with DOT 5 and all with good results. Best part if those new lines leak when checking out the system it doesn't eat any paint it may come in contact with. Bob, thanks for pointing out the lubricating thing. I never even thought about that but never had a problem with the rebuilt parts I have used.  Maybe I have been lucky. I will take that in consideration in future changeovers. Gary