66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

[Mark E.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Larry,

I prefer data to theory. Next time you bag the car do the open container of DOT 5 test and mark the before and after level. Regardless of the speculation of some, I believe the evaporation will be nowhere near 80%.

Gary

Right. Evaporation cannot explain 80% loss in a small sealed (or virtually sealed if there's a leak) system. The fluid is going somewhere; you just haven't yet discovered where.

Keep us posted what you find.

[Larry E.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Right. Evaporation cannot explain 80% loss in a small sealed (or virtually sealed if there's a leak) system. The fluid is going somewhere; you just haven't yet discovered where.

Keep us posted what you find.

Mark: Thanks for reply. One must remember the manual brake master cylinder on a 66 is NOT THAT BIG TO BEGIN
WITH. SO>80% sounds like a lot but it is not that much. The can of DOT#5 from the parts store is not that big and
it hardly uses 50% of it. Thanks to you and everybody else for all the advice. Will keep a close eye on this and will report
the outcome when I know it. Larry

[Edward J.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Larry, another thought was to check the boots around the pistons for sweating, any wetness around boots is a sign of fluid behind the boot. Sometimes if you take a pocket screw driver you can peel boot back slightly if you see fluid you found your leak.

[John F.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Check every line from front to all four corners, up to and including the brake calipers.

[Jim D.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

I installed DOT#5 in my 1960 back in 1986. Every component of the brake system was new or sleeved at that time. I checked the level in the M/C a few days ago in preparation for summer driving and the level is the same as it was in 1986. That stuff doesn't evaporate.

[Owen L.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Can't help but throw my hat into the "doesn't evaporate" ring. It's difficult to find evaporation ratings on silicone brake fluids (or even Dot 3,4,5 fluids). However, if you look at the MSDS for silicone brake fluids, you'll find they indicate something along the same lines as this:

Inhalation: This is a viscous fluid that does not easily form a mist or vapor and, therefore, inhalation hazards are minimal.to?

[Larry E.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Can't help but throw my hat into the "doesn't evaporate" ring. It's difficult to find evaporation ratings on silicone brake fluids (or even Dot 3,4,5 fluids). However, if you look at the MSDS for silicone brake fluids, you'll find they indicate something along the same lines as this:

Inhalation: This is a viscous fluid that does not easily form a mist or vapor and, therefore, inhalation hazards are minimal.to?

Owen: Thanks for reply. Let's explain the "Car Jacket" Procedure> After car is in the bag a package of "DRY-Z-Air" is put in a container made of of White Pellets. It's job is to draw out all moisture into the container which becomes a liquid. In it's makeup the liquid in the
container WILL NOT RE-EVAPORATE INTO THE BAG. This liquid is thrown away when car is taken out of bag. Don't ask how
this works. I guess these white pellets "stimulate" evaporation in the bag and turn this moisture into liquid. A lot of Motor
Home guys use this stuff to store their units. This with "no pedal usage" and small shrinking of the seals causes some of
the brake fluid to escape and evaporate into the container. This is my theory for now since everything returns to normal during
the Summer Months. Larry

[Patrick B.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Larry- If any of the DOT 5 makes it into the container with the water, it will not mix with the water. The container would have two separated phases of liquids. I suppose the Silicone fluid would be the top phase. Do you see distinct phases in the liquid container?

[Owen L.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Just my armchair mental musings: Even if it did evaporate easily, I don't see how it's going to get out of the sealed brake system by evaporation only. Losing 80% (of what, a cup of fluid?) isn't going to seep away invisibly. The molecules are pretty large to go through the rubber seals and hoses. If the material pores were that large, water would be seeping in at alarming rates.

[Larry E.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Larry- If any of the DOT 5 makes it into the container with the water, it will not mix with the water. The container would have two separated phases of liquids. I suppose the Silicone fluid would be the top phase. Do you see distinct phases in the liquid container?

Patrick>I use 3 containers per car when I bag them. All of the containers are full(Liquid) in the Spring when car is taken out of the
bag. I really have not noticed(or looked that closely) if there is more then one phase. I DO KNOW THAT THIS LIQUID IS
VERY NASTY STUFF. WHEN I DUMP IT ALONG MY BUILDING OR FENCE LINE IT MAKE THE BEST WEED KILLER YOU
EVER USED! I will look next time. Thanks/Larry

[Larry E.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Just my armchair mental musings: Even if it did evaporate easily, I don't see how it's going to get out of the sealed brake system by evaporation only. Losing 80% (of what, a cup of fluid?) isn't going to seep away invisibly. The molecules are pretty large to go through the rubber seals and hoses. If the material pores were that large, water would be seeping in at alarming rates.

Owen>Thanks again for reply: I suppose we can go on and on about the theories of why this is happening. HERE IS THE BOTTOM LINE>
WHY DOES THIS HAPPEN ONLY WHEN STORED IN THE WINTER WHEN CAR IS NOT USED AND DOES NOT HAPPEN
IN THE SUMMER WHEN CAR IS USED. STILL WAITING FOR A LOGICAL ANSWER. LARRY

[Larry E.]

Re: 66 C2 DOT#5 Brake fluid "disappears" during Winter Storage

Thanks again to all that are trying to help. I SHOULD HAVE ASK THIS QUESTION A LONG TIME AGO WHEN
THIS STARTED.>>

DOES ANYBODY ELSE ON THIS DISCUSSION BOARD USE THESE "CAR BAGS/OMNI BAGS" FOR STORAGE IN THE
WINTER THAT USE DOT#5 BRAKE FLUID??? OR KNOW SOMEBODY THAT DOES.> LARRY