Brake fluid flush vs top ups
 

Do you guys flush the whole system annually? or is bleeding them and topping up the fluid before every event sufficient?

I was wondering how other guys do it because (I am not sure if it's necessary )I like to bleed the calipers before every track day even though pedal is fine just incase there might be a little boil from last event. (Nothing crazy, just pump hold bleed 4X per corner ends up with no bubble usually if pedal was fine before bleeding)


Also I've bought a power bleeder from tse last month and it's impossible to get it to seal. the rubber piece is too small and move inside the cap while tightening. After trying to get it to seal many times, I applied some shoegoo/goop to glue the rubber piece into the center of the aluminum cap, and got it to seal once and then after i took it off to top up the reservoir, the rubber piece came loose and it was impossible to seal again. Are they like this or do I have a smaller than normal rubber washer? it did work very well during the whole 5 minute when it was working correctly. I had to fall back to getting someone to pump and hold the pedal for me

you are supposed to do a flush every 90 days. I think that's probably a bit excessive. I definitely think its a good idea to do a bleed after every event though. Just bleed out a bit on each corner and top off the rest. You can go longer between flushes that way.

This is very interesting to hear. Have you called TSE and talked to them about the power bleeder? It is on my to buy list, but further down. If they do not get a good seal then I probably will end up passing on one.

The rubber seals have a tendency to fall out, but I've never had any problem getting one to seal as long as it's in there and the cap is tight enough. I've heard this same complaint from at least one other person, and I was able to get theirs to work as well just by tightening it down a bit further.

I use a home made vacuum cleaner type bleeder and pull a bit of fluid through the system before every event. Just to be sure.
Full flush once a year.

I've always been lead to believe that due to it's highly hydrophilic nature, brake fluid doesn't have much of a shelf life once opened. So I always end up doing a full flush with the mindset that I'll either use it or throw it away. Have I been completely mislead, or is there some way of storing the left over fluid that keeps it from getting 'wet' and dropping the boiling point?

This is pretty much bullshit, if the container is airtight, the system will come to equilibrium and no more water will be absorbed by the brake fluid.

The screw cap on your average plastic bottle of brake fluid is not airtight.

--Ian

So teflon tape the top of it :party:

Old fart noobie here. I don't know if the following info will help you but...

1. I actually found that getting one of these vaccuum hand pump bleeders from harbor freight was much more convenient that getting the power bleeder that you attach to the brake fluid reservoir.

Brake Bleeder and Vacuum Pump Kit

https://www.miataturbo.net/attachmen...ine=1373121399


El cheap old fart bought this generic one from harbor freight, which I think was around $20 after a 20-25% off coupon they have every so often. There's one slightly better for $30ish...And ideally you can use these to test for vaccuum leaks elsewhere too (practically, if you get brake fluid all over the place inside the hand pump, you probably don't want to use it for something else)...

If you're local to where I'm at, you're welcome to borrow it if you don't want to buy one yourself.

2. Regarding the power bleeder. If the provided cap isn't working anymore, you could find a cheap used brake fluid reservoir cap, drill a small hole in the center, and attach a new hose fitting to it, ensuring a good seal (using rtv in between the hose fittings... It would be a much more tighter fit than those caps that the power bleeder comes with.

I did this for my previous audi a4...Well, actually I was cheap and didn't actually buy a power bleeder for $50.+..Instead I made one myself for $15, out of one of those bug sprayers, some left over hose and fittings fittings, an extra brake fluid reservoir cap, and a vacuum gauge from a broken tire pump...... Something like this (this isn't mine, but it looks similar)....

https://www.miataturbo.net/attachmen...ine=1373121399
https://www.miataturbo.net/attachmen...ine=1373121399


There's DYI instructions all over the internet that describes how to make one. I'm happy to repost what I did here if you need to, but you can search and find them, as many people have done this.

The cap picture above is not the one for the miata, it's for VW/Audi.... There might be a little challenge for the miata, because the top cap isn't flat... There's also generic caps from your local cheap auto stores in the "Help! brand" that might fit....

Don't have any other opinions about how often to bleed the system. I defer to the experts here.

A jar, a piece of tubing and a shop vac seam so much easier.

FWIW i just had the same problem with this fitting not holding pressure above about 5psi, and allowing fluid to come gushing out of the reservoir (fun) and no matter what I did it would not seal. I tried several different ways of aligning the rubber seal (it seems just a bit too small for the application), and finally took your advice and tightened the cap down in increments while pumping to the point that I was scared that I was going to break something, and it never sealed. It got to where I could sorta bleed the brakes just by using the motive pump to build pressure, but there was always a hissing noise due to a leak, and I had to pump frequently and couldn't get above 10 psi for more than 5 seconds.

When I "finished" (it seems there's still air in the system somewhere...) I removed the cap and I'd tightened the cap so far that the gasket had actually gotten cut by the pressure against the reservoir. On a whim I tried replacing the gasket with some cork/rubber composite gasket material i had laying around, making the new one about 3/32" larger in diameter, so that it fit very tightly into the cap. Now it seals absolutely perfectly, without the need to have the hulk crank it down onto the reservoir. Hopefully this will be helpful to someone.

Edit: Just re-bled the lines with the cork gasket, and it was quite easy to get all the air out. The pedal is rock solid like it ought to be!

We bleed after every weekend. Complete flush 2-3x a year which probably works out to about 25 track hours between flushes I'd guess. We have a Motiv bleeder but never use it. Manual pump into a bottle works.

I do a full bleed 3 or 4 times a year because a couple of little bottles of fluid are a lot cheaper than body and frame damage. It is a pragmatic decision.

In my experience vacuum bleeding is very unreliable. It seems to always suck air through the threads at the base of the bleeder screw and leave air in the system.

I either do it the old fashion way (2nd person pumping the pedal) or with a pressure bleeder on the reservoir.

I also flush about once a year. Fluid is cheap and I feel all warm and fuzzy knowing its fresh ;)

I have that problem all the time using vacuum bleeders. I tried using liquid teflon stuff once. Didn't really help. Using someone else to pump pedal and bleed usually the main method. Might build a pressure bleeder now that I see one. Might save me a few bucks.

Don't have any friends to pump the pedal around here :sadwavey:

No need. Just make sure the hose coming off the bleeder is full of fluid. We do one person brake bleeding all the time. All you need is a empty plastic water bottle with it's cap and a piece of clear vinyl hose that fits tight over the bleeder. I have yet to encounter any circumstance that indicates the need for any other equipment for bleeding or flushing brakes. The Motiv bleeders is faster for flushing but more of a PITA for simple bleeding. We are bleeding brakes constantly at our shop, complete flushes a lot less often.

When flushing the system a few times a year, we drain the master in order to clean the reservoir. After a few months, sediment will build up in the bottom of the master. Simple test to see if your car is ready for a system flush, wearing a white or light colored latex shop glove, touch a finger to the bottom of the master reservoir. Got any sediment stuck to the glove? Drain, clean the master reservoir with isopropyl alcohol, fill and bleed. If it's an ABS car go cycle the ABS once after bleeding then re-bleed. When you empty the system, the ABS pump will usually get a few bubbles in it. Dealers have SST's to cycle the ABS pump in the shop. We have the street in front of the shop.

Basically this Genesis Technologies Racing Brake Bleeder Bottles

https://www.miataturbo.net/attachmen...ine=1373740595

I thought you needed to bench bleed the master any time you completely empty the reservoir?

I have never had a problem just bolting it on the car and doing a 2-man bleed with a fresh/empty master cylinder?

Maybe I'm dumb, but how do you one person bleed with just the bottle? Squeeze, crack bleeder, let go?