VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   RV General Discussion/News (https://vansairforce.net/community/forumdisplay.php?f=2)
-   -   Mobil 1 ATF as brake fluid.. (https://vansairforce.net/community/showthread.php?t=148051)

maniago 12-04-2017 06:54 AM

ATF isnt lacking anything. It actually has "other things" in it, like friction modifiers to help with the clutch packs in the tranny. Those dont make much difference a brake system; verifying seal compatibility is all thats required.

In a sense general, any "hydraulic" fluid would work because its the liquid incompressibility characteristic that were after here. Additional characteristics that make it compatable with flight regimes, water absorption etc etc are what would make it (or any fluid) approved for airplanes. My guess is that were just not operating in the extreme environments that approved fluids are tested to so we can get away with Mobil1 in this application. IOW, "its no factor". I plan on using it. Each to his own however.

FasGlas 12-04-2017 08:42 AM

I've personally never had a brake system go dry while flying but they do sometimes get a low if not checked every so often and serviced every so often but the thought comes to mind that if you could service your brakes at a field where there's no one around you must be carrying tools, as most of us do, and if so why not store a small bottle of 5606 in your tool bag? Those little plastic bottled water bottles work great for fluid, cleaners, etc. small and easy to carry in your tool bag. Unless you've blown out a brake system very little fluid is needed to fill a low brake.

db1yg 12-04-2017 06:08 PM

Mobil 1 ATF
 
I converted to Mobil 1 ATF 4 years ago and have had good service and no problems. At the time of the conversion I also changed out the caliper o rings to Viton. Both changes were to raise the "flash point" and to use a product that I can purchase most anywhere.

To each his own.

Cheers,

db

Charles in SC 12-04-2017 07:14 PM

I am just curious. My -7 is not flying yet. Do you have to add fluid out on a trip very often? In 5000 hrs of flying a pretty good assortment of homebuilts and certified planes I cannot ever remember needing to add brake fluid when I was on the road.

RV7A Flyer 12-04-2017 10:19 PM

Quote:

Originally Posted by Charles in SC (Post 1223366)
I am just curious. My -7 is not flying yet. Do you have to add fluid out on a trip very often? In 5000 hrs of flying a pretty good assortment of homebuilts and certified planes I cannot ever remember needing to add brake fluid when I was on the road.

500 hours w/ M1 ATF and no issues (after I fixed leaks due to *&^% NPT fittings, but that was a different issue). I haven't even had to add any fluid yet (knock on wood).

It's not adding or topping off while away from home that I would worry about...it's a leak that requires disassembly/repair in the field, which then means possibly draining and filling/bleeding a brake line. That's why I chose ATF...I can get it pretty much anywhere, and don't need to carry any around with me.

gasman 12-04-2017 11:23 PM

In a perfect brake system (no leaks) if your reservoir was low on fluid, it would mean that your brake pads are worn down and have moved toward the disc along with the piston. If you push the piston back in and installed new pads, the fluid should be full in the reservoir.

Leaks are the only reason to add fluid between brake pad service. This is not to say you shouldn't replace the brake fluid at pad change..... Just pump it through as you add fresh fluid to the reservoir.

TS Flightlines 12-05-2017 09:20 AM

notice none of the brake manufacturers have chimed in here?

ChiefPilot 12-05-2017 01:08 PM

I've been using Mobil ATF in my brakes for the last 5 years and 900+ hours. No problems. It has a higher flash point than 5606 - I had a much harder time inducing ATF to combustion than 5606 when I proved this for myself. It is compatible with the standard seals etc no only by specification but also by empirical evidence. In the world of experimental aviation, this is perhaps one of the "safest" experiments I have performed.

To claim that it is not safe because it is not "certified" is cowardice, done perhaps only to prop up ones own choice or to try to promote some kind of air of superior knowledge where none otherwise exists. Certified does not mean superior; if it did, we'd all be flying factory built aircraft which come complete with certified brake fluid.

Walt and others engaging in the FUD around lawsuits and such seem to be doing so out of ignorance - does it really pass the smell test that a lawsuit would zone in on the brake fluid while at the same time ignoring the amateur built status and use of uncertified parts *provided by the kit manufacturer*?

ChiefPilot 12-05-2017 01:11 PM

Quote:

Originally Posted by TS Flightlines (Post 1223444)
notice none of the brake manufacturers have chimed in here?

The irony with your statement is almost too much.

TS Flightlines 12-05-2017 01:44 PM

David that is a great point. My thought was that IF there was compatibility issue they would say so. Beringer has 2 different versions of their stuff---one for DOT4 and one for mineral oil meeting Mil-PRF-87257. So I would think that unless the ATF met the 87257 specs dont use it in Beringer systems. Grove, Matco, Cleveland, dont know.

Tom


All times are GMT -6. The time now is 06:16 AM.