Does anyone make a vented brake reservoir cap to fit the FFR brake reservoir

[Itchief]

I am trying to find a vented brake reservoir cap for the FFR reservoir I drilled a small vent hole and loosely packed it with cotton but I would like to find a better solution

Thanks

Rick

[davekp]

You probably shouldn't have a vented cap. Even a small vent allows the fluid to absorb moisture, and greatly reduces the boiling point of the fluid, thus ruining it.

[wallace18]

There is a reason that no OEM reservoir caps have vent holes. Like it is said above brake fluid is hydroscopic.

[Boydster]

But most OEM's do have a flexible bladder that seals the fluid while allowing for expansion and contraction, temp changes, slight fluid loss and normal level changes during operation. My F5 reservoirs, and I suspect the OP's, do not have this feature and I suspect that what he was wanting.

[Railroad]

I am on the trail of a duck bill one way valve. It is used in the oiling system of a chain saw. I am considering drilling the cap and putting it in the hole. It will allow external air into the reservoir, not good, but will prevent a vacuum from being created by the lowering of the fluid level. Still on the fence about the whole process and am looking for a bladder type separater to keep air from the fluid. I need to locate the rubber baffle used on a Honda 750-4 motorcycle front brake reservoir. I think it might work.

[FFinisher]

But most OEM's do have a flexible bladder that seals the fluid while allowing for expansion and contraction, temp changes, slight fluid loss and normal level changes during operation. My F5 reservoirs, and I suspect the OP's, do not have this feature and I suspect that what he was wanting.


Current FFR caps have such bladder. Might suggest contacting them for one of those.

I am not sure what version the OP has.

[Boydster]

Current FFR caps have such bladder. Might suggest contacting them for one of those.

I am not sure what version the OP has.

Good news, then. Mine are about 2 years old.

[Itchief]

I agree that brake fluid and moisture are not a good combination but I think that FFinisher has the correct answer to my problems

The old style brake reservoir caused a vacuum to build up on the low pressure side of the brake system and over time air would be drawn into the system through the weakest point the master cylinder seals and results in a mushy brake pedal.

Over the course of about 12k miles my brake pedal went from rock hard to mushy it’s not something that happens overnight the pedal just gets worse with time. Once I got the air out of the system the brakes are rock solid again.

FFinisher thanks again for the help it looks like I will have to order a new reservoir kit because the new cap doesn’t look like it will fit the old reservoir

Rick