Easy method for bleeding brakes.

[tbro]

Hi all,
Before we start lets get one thing clear "If your NOT confident about your mechanical ability maybe your better off getting this job done by a professional". I say this for one main reason, I have seen many times over my years as a mechanic, people trying to save money and end up costing them a fortune because of inexperience or not having the right tools etc.

Boags said in his post about getting his race car :made the day so much easier with your amazing trick re brake bleeding: and a some people have asked about this trick.

So sit down grab a coffee and read!!!

I hate pumping brake pedals!!! why, clutch master cylinders are designed to travel the whole range of the cylinder, that's how they work, on the other hand or leg, brake master cylinders only ever travel approx 5% of the available cylinder. The only time this changes is when your brakes need adjusting or worse, you have a fluid leak and/or hydraulic failure!! make sense? hope so!!

The basics when bleeding brakes, if just to change fluid or after caliper rebuild is all the same.
What you will need,
1/2 m clear tube to go over bleeder approx 1/8 dia
large syringe from chemist ask for a catheter tip syringe 50ml
Brake fluid 1 ltr a different colour to what you have in your brake system now, I'll explain later!!
container or you can use your oil drain bucket.
coffee/tea or beverage of choice non alcoholic!!!!

First step is to mark the master cylinder reservoir at the level that the brake fluid is now, (unless you have had a fluid leak) this is so you will know when your disc pads are worn down.As your pads wear down goes the fluid.

Jack up the car, place on stands and remove the wheels. Grab yourself a length of clear tube to fit over the bleeder nipple. Suck out all the old fluid from the master cylinder with your syringe and tube. Refill with new fluid and turn the M/C cap over and place on resevior.

Place you drain container under the caliper and run the tube to the container, I like to have the hose going up then a gentle bend downwards, this way you can see the fluid coming out and see the colour change when the new fluid comes through. Crack open the bleeder and leave the hose to drip brake fluid

Now go and get your beverage of choice, this step will take approx 15mins. Have your drink, start polishing your car, start changing oil whatever, but, keep an eye on the brake fluid reservoir and don't allow to go under 1/4 of the way down. top up the cylinder when it at the low mark and have a look at the fluid dripping out of the hose, it will be nice clean fluid, and a different colour that why we change the brake fluid colour.Grab your spanner and tighten up the bleeder, you just tighten it up, the fluid will still be running out so no air can go in!!!!Do this to all 4 wheels, rears first then the fronts.Some vehicles are supposed to be bleed in a certain routine but doing it this way I've never had any problems.
If you have run the system completely out of fluid this method will still work however you will need to open the bleeder and tap your finger over the top of the bleeder for a few minutes until fluid starts coming out, this causes a vacuum and helps the fluid to start to run, re:
Once the fluid starts to run place on your clear tube and go do something.

Now this is the method I was taught when doing my time 37 years ago and I've used it ever since and never had a problem if everything is in good condition. If the fluid won't run after you've had the system apart you have a leak somewhere, recheck all joints and recheck that everything is tight.Of course someone will disagree with my method and that's their privilege. If you want to go buy the gear to do the same thing but spending lots more $$$ buy one of these, I have one but only use it for sucking out fluids and bleeding diesel engines.


If your still not comfortable doing this, take my advise and get it done professionally. If your in Brissy give me a yell and we'll arrange a weekend and I'll happily show you how to do it (you bring the brake fluid and any other fluids hint hint)

BTW I still change my brake and clutch fluids after every track run, keen hey!!

Terry

[tbro]

Great method. Can this one be done with hydraulic clutches as well Cheers.

Exactly the same, just a bit quicker!!!


Terry

[Old Dude]

makes a lot of sense Terry, thanks for the info. I was always taught the pump, hold and Bleed method, but I will give this a go next time.
Thanks
Regards
Old Dude

[Guran]

I used this technique yesterday to bleed my brakes. Seemed to work a treat at the time, as it cleared a bit of cloudy fluid from the front brake lines. But thinking about it afterwards, there is potential for the fluid to bleed but still leave some air bubbles in the lines. This could possibly happen at any length of tube which loops up and then down. Gravity draining might not create enough flow to push the air pocket out. Please refer attached schematic. I didn't notice any sponginess in the brake pedal after using the gravity bleed method, but if you want to be really sure, it might be still best to go with the pedal pumping method.

[tbro]

I used this technique yesterday to bleed my brakes. Seemed to work a treat at the time, as it cleared a bit of cloudy fluid from the front brake lines. But thinking about it afterwards, there is potential for the fluid to bleed but still leave some air bubbles in the lines. This could possibly happen at any length of tube which loops up and then down. Gravity draining might not create enough flow to push the air pocket out. Please refer attached schematic. I didn't notice any sponginess in the brake pedal after using the gravity bleed method, but if you want to be really sure, it might be still best to go with the pedal pumping method.

If the Master cylinder is keep topped up with fluid there is no way that air can stay in the lines and caliper. The bleeder nipple is at the top of the caliper so that air cannot be trapped, the clear tube is only to make bleeding less messy. you can put a container under the wheel assembly and simply open the nipple and gravity will push the fluid down to the nipple.
In the olden days one manufacture Rambler released a car with the bleeder nipples slightly down from the top of the cylinders, even with a pressure bleeder it was nearly impossible to get all the air out of the system without actually removing the backing plates and laying them om their side. I found out this after about 4 hrs and 10l of brake fluid.

Terry