Brake fluid flush: tips and tricks?

I need to flush the brakes on the RX-7. Not surprisingly it's been awhile since I've done this so I'm looking for advice.

Fist off, what fluid? The previous owner said he used DOT 3. Everything I've read says I should use DOT 4. Thoughts and recommendations?

It's also a crap shoot as to whether I can get help or not, so I'm looking into the one man bleeder kits. Harbor Freight has a setup, how is that? Any tips on how to make it go smoother?

Thanks again.

J

I have the Motive pressure bleeder and it works great. Probably one of the best $50 I ever spent, as now I bleed the brakes on all my vehicles at least once a year. Used to never do it because it was a PITA to do it correctly by myself. Might need a few different adapters to work on your different cars, but makes doing the job a cinch.

I've been using DOT4 in everything these days. Funny, but it's hard to find around here, so when I do find it, I buy like 2-3 big bottles of the stuff so I have it around.

I hate messing with brake fluid, but I love my Motive pressure bleeder.

I bought some bleeder screws for my RX-7 that have a one-way check valve in them. haven't used them yet though.

now you know that story.

Does the procedure change when you're flushing a vehicle with ABS?

It may depend on the car, but it seems that as long as you don't get any air into the ABS controller, the procedure doesn't change. If you do get air in the controller, you may need a computer to electronically 'cycle' the system (VAG cars are like this).

Use a syringe to suck out most of the M/C fluid. Top off with fluid of choice (I like ATE Super Blue and Type 200, so the change in color makes it easier). Attached Motive and pressurize. Bleed off fluid at each corner until fluid color changes, making sure not to run the reservior dry. I've found that just using the Motive for pressurizing and not for fluid makes things go faster and can be less messy.

belteshazzar wrote: I bought some bleeder screws for my RX-7 that have a one-way check valve in them. haven't used them yet though.

Speed Bleeders. Your FLAPS (Pep Boys) should have them in the Help! section. I had those on my Triumph. Awesome little devices, although they don't seem to work as well if the system has a lot of air in it.

Turkey baster to suck the old fluid out of the reservoir. Then you refill it with new fluid.

Jar and a hose at each wheel. Pour a little fluid in the jar, drop the hose end into it, other end of the hose on the bleeder. Crack it about 1/4 turn. It will bleed itself. If you're impatient, push the brake pedal a few times. If you use clear tubing, you watch to see when the fluid becomes clear.

Repeat on each corner. Done.

Prestone synthetic dot 3/4 fluid is good and cheap.

I have a how-to write up on a "make your own pressure bleeder for under $20" on my home computer. I'll post the link when I get home. Haven't tried it myself but will soon.

Found it online! Goggle is great.

http://www.bmw-m.net/TechProc/bleeder.htm

foxtrapper wrote: Turkey baster to suck the old fluid out of the reservoir. Then you refill it with new fluid. Jar and a hose at each wheel. Pour a little fluid in the jar, drop the hose end into it, other end of the hose on the bleeder. Crack it about 1/4 turn. It will bleed itself. If you're impatient, push the brake pedal a few times. If you use clear tubing, you watch to see when the fluid becomes clear. Repeat on each corner. Done. Prestone synthetic dot 3/4 fluid is good and cheap.

Ah the old gravity bleed. It works AWESOME if you are patient enough, but keep an eye on the master cylinder.

I use a Motive bleeder. I use Valvoline Synthetic brake fluid for most applications. If I'm feeling particularly abusive (summer track days), I'll use ATE Blue/Gold.

Plus a billion for the Motive power bleeder.

I can jack 4 corners, take off the street wheels and street brake pads, put on the track pads, push fresh fluid through all 4 corners, put the track wheels on, and drop the car in about an hour, alone.

I do a full flush before the first event of the season and push the contents of each caliper through every event or 2. For a single day @ Shenandoah I might give it a skip, but 2 days at Summit or VIR I always have fresh fluid where it could boil.

In a '98 M3 with Hawk HT10 pads and Toyo RA1s I've yet to have a hint of fade using ATE Super Blue or Yellow 200. It's like $12/liter.

I have a piece of 1/4" steel plate that I tapped for 1/4" NPT. I screwed in an air fitting. All I have to do is turn the regulator down to about 5 psi, clamp the steel to the top of the reservoir, hook up the air hose, then go to each wheel and bleed.

Next time I go to the junkyard I'm getting a brake reservoir cap to do my own pressure bleeder, to hell with the vacuum bleeders!

While I agree with abandoning vacuum bleeders, beware of pressurizing stock reservoir caps. In my experience, it always leaks, spraying brake fluid onto the firewall and fenders. Only when I use a pressurized system like curtis73 described can I get it to seal.

Remember to, since it's a pain in the butt to some degree to open up a pressurized system, you're far more likely to try to eek out that last bit of fluid before taking the cap off, and manage to push air into the system. BTDT, more times than I care to admit.

Speed bleeders are nifty, but I've never understood their draw. They do the exact same thing as my tube leading down into a can. And since I still would use a tube and a can, I'd gain nothing with a speedbleeder. I know they are loved by their owners, but I suspect a whole lot of that love is to justify the money they just spent.

Really and truly, with my piece of tubing and a can, I can bleed or flush brakes every bit as fast, if not faster, than a person with a pressure bleeder or with speed bleeders.

In reply to benzbaron:

Some style caps don't work, so be careful.

I bought the correct adapter from motive, and they bought a garden sprayer at the local hardware store to make my own pressure bleeder. Works darn well.

Ten times better than asking the wife to help me bleed the brakes(that isn't healthy for our marriage).

Thanks for the responses. Being a complete cheapskate, I'm going to try the gravity bleed first. I'll let you know how it turns out.

BTW, I'm currently waiting for AAA to come unlock the RX, I uhmm, locked both keys in it .

i've been a brake engineer for 16 years, and i always gravity-bleed my personal stuff. usually because i don't always have a helper, but also because it's effective.

with ABS, bleeding doesnt really change, but when you do a pad change, NEVER push pistons into calipers without opening bleeder(s) first. don't want dirty fluid being pushed up the lines into the ABS valve.

One thing I like to do is to keep a can of ATE blue brake fluid and ATE clear brake fluid around. When I bleed I just use alternating colors. If I filled with clear last time, I fill the reservoir with blue. That way I know when the blue fluid starts coming out the bleeder, its flushed.

I am going to get a mercedes reservoir cap and tap it for a pneumatic line. Then I pressurize it to 5psi, and go about cracking the caliper bleeders until the brakes are good, but I am no brake expert. I've done two cars and one bike, and the biggest brake job was adjusting the rear drum brakes of the pickup correctly. It took me three tries.

I would also like to use colored fluid, yellow verses clear is really hard to tell. Given brake systems are pretty low volume you can assume you only need to bleed so much.

curtis73 wrote: One thing I like to do is to keep a can of ATE blue brake fluid and ATE clear brake fluid around. When I bleed I just use alternating colors. If I filled with clear last time, I fill the reservoir with blue. That way I know when the blue fluid starts coming out the bleeder, its flushed.

I do that too.

I have the Speed Bleeders for my FC and I think they work well. Besides being easier to work with, they are much stronger and less likely to snap off in the calipers than the stock bleed screws. The FC 4-piston front/vented rear caliper bleed screws are very fragile.

If you want a cheap fluid with a high boiling point, try Ford Motorcraft DOT3. 550°F dry boiling point. Can't go wrong for $5! Just make sure to change it often as the wet boiling point is low.

Don't confuse what I described with gravity bleeding. My method is not gravity bleeding. My method is a free one man speed bleeder bleeding techique. It's fast, easy and free.

Gravity bleeding is just letting gravity pull the fluid down through the system. This can work fine, but it is time consuming.

What I do is put the hose on the bleeder, drop the other end into a jar, making sure there is an inch of fluid in the jar and that the hose end is down in that fluid. Crack the bleeder about 1/4 turn. Now you can get into the vehicle and push the brake pedal and pump the fluid out. The viscosity of the fluid in the jar acts like a one way valve, and the fluid quickly drains out of the brake system.

If you use clear tubing, you can watch the condition of the fluid, as well as watching the air bubbles.

I do the same one man method. I lack the patience to gravity bleed. I use a cheap set I got from Sears consisting of a black rubber 90* with a flap-type check valve built in and a line to a plastic cup. Works very well and was very cheap. I try to remember to short stroke the pedal so I'm not pushing the MC seals past their usual operating range and into an area of the bore potentially pitted or otherwise in poor shape which would tear the seals.