Brake bleeding

[Sparx Macgyver]

I wanted to confirm something with you guys.

I can bleed the MC without taking it off the car, right? Like as in bleed it like the brakes using the bleed valves?

And ot confirm, the proper order of brakes is drivers rear, pass rear, pass front, driver front, right?

I had pressure, but it didn't stay for long. I plan on going through, and replacing everything brake wise anyway, I was just hoping I could drive the car first. If it matters, I haven't replaced the MC yet.

[70 Cam Guy]

You can use the bleeders on the master to bleed it on the car

What exactly prompted this project? Is your pedal sinking after the initial application? The brakes are a sealed system and if the pedal is fading under normal driving, you should suspect a loss in pressure via an external leak or possibly an internal leak (maybe the master cylinder)

Air in the lines can cause a spongy/squishy feel in the pedal.

Have you inspected your wheel cylinders and calipers for leaks? Likely you will need to carefully pull back the rubber boots on the wheel cylinder and caliper piston to expose a leak. Evidence of leaks can sometimes be seen by leak trails in the dust or contaminated pads/shoes. These areas should be bone dry (assuming no rain)

I have read the same order of bleeding you listed except that I had better luck with the traditional order or pass rear, driver rear, pass fr, left fr. Your mileage may vary, I'd still try the order commonly recommended here first.

[beandip]

Andy is right , but one more thing . If he Master is shot it will leak back into the vacuum booster . The brake fluid will damage the diaphragm of the booster, so if you loosen the master and it is wet on the firewall side , don't wait replace the master. Vacuum boosters are SPENDY.

Gary

[70 Cam Guy]

Andy is right , but one more thing . If he Master is shot it will leak back into the vacuum booster . The brake fluid will damage the diaphragm of the booster, so if you loosen the master and it is wet on the firewall side , don't wait replace the master. Vacuum boosters are SPENDY.

Gary

Agreed, very good advice. It's also very easy and quick to check

[Sparx Macgyver]

What prompted the project was that the brakes are non-exsistant. Like nothing to them. And that's was before and after I replaced the rear drums & shoes.

Thanks for the tips. I'll look at those things you've pointed out.

[70 Cam Guy]

Right on, you never know sometimes.

If you crack the bleeders and see air bubbles come out before or with the fluid, you know you have air in the lines.

Good luck!

[Sparx Macgyver]

Thanks Andy. I'm hoping to take a crack at it tomorrow since I'll have the day off. It'll make things easier than having to contend with my work schedule.

What size hose am I supposed to use for the bleeder's? 3/8" is too small, 5/16" is nice and fit, and 1/2" is a tad big.

I ask because fluid was seeping through yesterday afternoon from the 5/16". By seeping I mean it covers the valve completely, but where the hose meets the MC, it just sorta seeps through.

[70 Cam Guy]

If I follow what you're describing, I just use clear hose that fits snugly over the nipple of the bleeder (maybe 3/16" or 1/4" ID). If you completely cover the bleeder with hose it is more difficult to open and close the bleeder as the brake pedal is held, and then released. I just jam on whatever I can so it's snug and doesn't fall off as I open and close the bleeder

I don't have a picture of my Gatorade brake fluid bottle but if you're looking for a catch can, this works

http://www.bluepoof.com/motorcycles/howto/svs_bleeding_brakes/bleeding_brakes.JPG

[Zedyone_kenobi]

Just a note, before installing your hose over the nipple, make sure its clean. IF it is dirty or corroded a bit, then it will be hard for the hose to form a tight seal.

[Jeff G 78]

To bleed the MC, simply use a snug fitting clear hose that is 6" long. Remove the reservoir caps and route the hose from the bleeder into the reservoir below the fluid level. Crack the bleeder just enough to get fluid flow and SLOWLY pump the pedal. With the hose in the fluid, there is no need to open and close the valve. Just keep pumping until there are no more bubbles. Close the bleeder and repeat on the second bleeder port. It works every time. If you loosen the bleeder too far, you can suck air through the threads. If you think that is happening, remove the bleeder and apply a small amount of grease to the threads to seal them.

One word of caution, if your paint is nice, be sure to lay lots of rags down under the MC. Also cover the fender with plastic or towels. Brake fluid will eat right through paint.

Edited February 3, 2010 by Jeff G 78