Brake Bleeding - Do it yourself

[Mike]

This was posted to our mailing list by steve j daniels,

Hey folks;

I saw all of the talk about brake bleeding kits. The

speed bleeders are pretty cool, I checked out their

web site, and I think the idea is sound, but it'll

cost you 31 dollars a car (seven dollars a bleeder and

3 dollars shipping).

I have a Mighty Vac, I thought that was pretty cool

for a while also. But if you ever used one, you know

that sooner or later you'll run into the situation

where you have to empty the reservoir and you end up

spill brake fluid all over your hands...worse yet you

pump brake fluid through the "pump head", and over

time brake fluid softens and swells the rubber hoses

and "fittings". I ended up just using the reservoir

and a rubber hose.

Here's an inexpensive Do It Yourself brake bleeding

Kit.

1. A 16 ounce plastic soft drink bottle and cap.

2. A 2 to 3 foot length of rubber vacuum line or wind

shield washer hose. It can be longer if you want.

3. A length of 2x4, I use an aluminum baseball bat.

I'll get to that explanation.

Now, take your hose and the plastic soft drink cap,

look at the hose and choose a drill bit size that will

allow you to drill a hole in the cap that will give a

tight fit when you pass the hose through the cap. You

don't want the hose to pull out of the cap easily.

Next, drill another very small hole it the cap, this

will be a "pressure relief" hole, a sixteenth of an

inch is good.

Screw the cap back onto the bottle and push the hose

home until it touches the bottom of the bottle.

If your bleeder is working and free, put a box end

wrench on the bleeder, then push the end of your hose

onto the bleeder. Crack open the bleeder a quarter to

half a turn. Set the plastic bottle on the ground

standing straight up. Now you can start pumping the

pedal, slowly please. "I like to pump out almost all

of the old fluid first, our you can take an old

kitchen baster and suck out all of the old fluid first

and top up with new fluid to start with. But anyway

the idea is to get all new fluid throughout all of the

brake system.".

The idea here is to pump in enough fluid into the

bottle so that the end of the hose is submerged, you

pump until no more air bubbles come out of the hose

end. Now this is where the length of 2x4, or baseball

bat comes into play. Push the pedal all of the way

down to the floor and place/wedge the 2x4 between the

pedal and the seat cushion. "I can't tell you how long

that is, I've never bothered to measure this, you'll

just have to figure that out for yourself." Now you

can close the bleeder screw. Don't forget to watch and

top up the reservoir, or else you'll pump air into the

system and you'll have to start over.

Brake fluid will attack the rubber hose that you use

and you will loose the tight fit that you want, but

this is so inexpensive, you just replace the hose when

that happens.

Bleeding sequence.... convention has it that you start

with the bleeder farthest from the master cylinder and

work back. This is for Dual Circuit Systems. Some

cars, not many, have Triangulated Systems, such as

Volvos. Volvos have four disc brakes and eight

bleeders screws, three on each front caliper, and one

on each rear caliper. In Volvos case you do need a

"map", you have to follow a set sequence of bleeding

or else you are just pounding sand.

Eh, I know that was a lot of words to describe a

simple operation, but what can I say, I don't have an

editor.

Steve J. Daniels

[hmsports]

I was shown a great do-it yourself method for bleeding the front calipers on an early Z. The problem with the pump/bleed method is that the calipers on early Z cars have two pistons with a single bleed screw on the inside of the caliper. It is difficult to fully get the air from the outside piston. Here's a foolproof method. Start with the right front caliper. Remove only the inner brake pad. Slowly pump the brake pedal one to two times. This will push the inner piston outward. Be careful not to go too far so the piston doesn't come out. Also, you will find it more difficult to push back in if it comes out more than about a 1/2" or so as it may **** sideways. This isn't fatal, but it makes it more difficult to get it straight and back in. Anyway, once the piston is out a bit, crack the bleeder valve (make sure to have a catch reservoir hooked up). Using a pair of groove joint pliers (monkey jaw as my Dad used to call them) slowly push the piston all the way in. Once it is in, close the bleeder. Repeat as necessary to remove all air bubbles. - usually takes no more than one or two times. Make sure to keep the fluid reservoir topped off. Once you as satisfied that all the air is out, put the brake pad back in and pump the pedal to seat the pad. Remove the outer pad and do the same thing. Repeat for the other caliper. This is very easy and as a racer, a guaranteed way to make sure there is no air left in the caliper.

[2ManyZs]

Of course the one thing a lot of people overlook is bleeding the master cylinder first. It will not only get rid of the old fluid out of the master cylinder easily, but if there is any air in the cylinder you will be bleeding at the calipers all day to remove any air that might have been trapped at the master cylinder.

Sounds like a good idea for bleeding the front calipers. Guess I'll have to try it. Never thought much about having air trapped in the piston like that.

[PUSHER]

Sorry for bringing this back from the dead. But where are these bleeder valves? Just got my z(first project car) and it has no brake fluid in it, so I'm assuming I need to fill it with brake fluid and bleed the brakes. Also what brake fluid should I use? Thanks.

[Bambikiller240]

On the back of the wheel cylinders and calipers.

Congrats on getting your Z!

Next step is to purchase Repair Manuals. If you have the money a Factory Service Manual is the best one to get, tho it is not cheap (approx $75). IMHO the Haynes (brand) manual is the next best and can be had very cheaply (under $15). These manual will answer so many of the questions you will have before you even need to ask, and will guide you in repairing and improving the car for many years. Worth the're weight in gold! (well, almost anyway)

[PUSHER]

Where do I get the factory service manuals? I searched but could only find cds.

[Bambikiller240]

They show up on eBay occasionally, but I don't know where you can get them in NEW condition. You might check with Motorsport Auto in LA, CA www.zcarparts.com as I think they sometimes have used ones for sale. Another place to check is to email Andy Russell z@datsundude.com I think he can get them too.

Good Luck!

[frank13]

I do not want to step on toes here Mike. But it seems like your describing leaveing the rear brake cylinder open while you pump fluid out of the brake master to fill the catch bottle enough to cover the end of the hose. The reason you want to cover the tip of the hose in the catch bottle is to help the fluid evacuate itself from the brake system. This should be accomplished be pouring some freash brake fluid in the bottom of said receptical. By pumping out old fluid through the lines you can suck air back in through the bleeder screw. The air then being brooken down into smaller bubbles every time the pedal is pumped. Traditionaly the method for bleeding brakes was to pump the pedal 3 or more times, then crack the line under preesure. In this day and age even on none ABS cars this has been found not to be the best way. Pump once smoothly hold, break line. Close wait a bit, repeat. The wait time is to allow the air bubbles to reconstitute themselves. Bigger bubbles air easier to get rid of. On the Z like you mentioned it is farthest first. Bleed the right rear, left rear, right front, left front. Getting rid off all the old fluid in the resevoirs first and then bleeding the master is great advice. If you want to flush the system or are cleaning the master Denatured alcohol (home depo) should be used. This also holds true for the Clutch system. :devious:

[Royce]

PUSHER,

This may start a big debate but if you are doing street driving then Castrol GTX is fine. I would stay away from Silicone brake fluids. If you are going to be doing track events than I have heard many folks use Ford Heavy Duty Truck Brake fluid which is a none synthetic. I use Motul brake fluid, it is synthetic but not silicone so it can be mixed in or bled into systems that did not previously have synthetic brake fluid in them without concern. Motul is not typically sold in stores and can be ordered from places that carry race brake supplies or general racing suppies like http://www.summitracing.com

Have fun!

[LEN168]

Hey, just wanted to say thanx, I used the 2x4 trick yesterday (actually I improvised and used a wedged an old sway bar against the seat moved all the way forward!) to bleed my clutch slave, worked great!!!!