Bleeding all 4?

[Wuddam I Thinkin]

Hello,
I have just put new rotors and pads on my 97 Escort LX and leaked brake fluid from the pistons.
I need to refill the fluid and bleed the brakes.
I am wondering if I need to bleed all 4 or can I just get away with bleeding the front 2?

Thank you...and if anyone wants to know about changing pads on a 97 escort I can give him the dirty lowdown on it...have penetrating oil handy.

[denisond3]

I guess you could try just bleeding the fronts, but: If the fluid level in the master cylinder reservoir dropped low enough for air to get into the master cylinder, the service manual talks about bleeding the master cylinder first. Then to do the bleeding beginning with the bleeder screw farthest from whatever brakes you opened up (front or rear) and then do the bleeders closer to the opened up portion of the brake system. The real test is whether the brake pedal has a firm feel and doesnt travel any further than it should before the car is being slowed.
I bleed all 4 wheels once a year on each of my cars, just to get the old brake fluid (and the water it contains) out of the system.

[Wuddam I Thinkin]

Originally Posted by denisond3

I guess you could try just bleeding the fronts, but: If the fluid level in the master cylinder reservoir dropped low enough for air to get into the master cylinder, the service manual talks about bleeding the master cylinder first. Then to do the bleeding beginning with the bleeder screw farthest from whatever brakes you opened up (front or rear) and then do the bleeders closer to the opened up portion of the brake system. The real test is whether the brake pedal has a firm feel and doesnt travel any further than it should before the car is being slowed.
I bleed all 4 wheels once a year on each of my cars, just to get the old brake fluid (and the water it contains) out of the system.

I opened up the front two. so that would mean start with the rears first i guess...
When I bleed do I open the screw completely or just enough to leak some fluid? Have the screw opened before the pedal is pushed or push the pedal first then open the screw?

How do I bleed the master cylinder? Is it connected to the reservoir?

Thank you!!!

[Torch]

Well, first of all did the reservoir get low enough that the hole in the bottom was exposed to air? Yes/no?

If yes, you will need to bleed all four brakes.

If no, you will only need to bleed the front that were leaking.

The way that I bleed brakes is to put the box end of a box end wrench on the bleeder valve then attach a a section of vacuum hose to the valve nipple, run the hose up through your strut spring then back down into a tin can or oil drain pan.

The reason I do it this way is because when the person pumping the brakes takes their foot off the pedal air can be sucked back into the brake lines, by having the tubing over the valve the brake fluid will sink back down and seal off the valve from air while the air travels up to the top of the hose.

Ok, (doing it this way) open the valve and leave it open, just loosen it a little bit don't try to unscrew it, have someone slowly pump the brake pedal until you start to see clear fluid come out the end of the hose, then close the valve and remove the hose and wrench, you are done with this side.

Move over to the other side and do the same thing with the other brake caliper, when you are done the brakes should be nice and firm.

The other way to bleed brakes is to have someone slowly pump the brakes three times then quickly open and close the valve. Either way have a third person constantly making sure that the hole in the bottom of the reservoir does not get exposed to air (add more fluid).

Hope this helps.

[Wuddam I Thinkin]

Originally Posted by Torch

Well, first of all did the reservoir get low enough that the hole in the bottom was exposed to air? Yes/no?

If yes, you will need to bleed all four brakes.

If no, you will only need to bleed the front that were leaking.

The way that I bleed brakes is to put the box end of a box end wrench on the bleeder valve then attach a a section of vacuum hose to the valve nipple, run the hose up through your strut spring then back down into a tin can or oil drain pan.

The reason I do it this way is because when the person pumping the brakes takes their foot off the pedal air can be sucked back into the brake lines, by having the tubing over the valve the brake fluid will sink back down and seal off the valve from air while the air travels up to the top of the hose.

Ok, (doing it this way) open the valve and leave it open, just loosen it a little bit don't try to unscrew it, have someone slowly pump the brake pedal until you start to see clear fluid come out the end of the hose, then close the valve and remove the hose and wrench, you are done with this side.

Move over to the other side and do the same thing with the other brake caliper, when you are done the brakes should be nice and firm.

The other way to bleed brakes is to have someone slowly pump the brakes three times then quickly open and close the valve. Either way have a third person constantly making sure that the hole in the bottom of the reservoir does not get exposed to air (add more fluid).

Hope this helps.

Fantastic! Thank you for the clear tutorial.

[Torch]

You're welcome :-)

[jakes1990454ss]

well you're supposed to only have to bleed the calipers on the brakes you were working on, more specifically, only the ones where air could have entered the system. This is the whole idea of bleeding the brakes. They are a hydraulic system, not pnumatic, or a mix of both for that matter. So, really, the only NEED to bleed your bakes is, first, if you take the caliper off of said wheel, or two, if you have a soft pedal or no pedal at all. And there is always a sequence when bleeding brakes. You start with the caliper furthest from the master cylinder first, working your way to the caliper closest to the master cylinder. For instance: If you replaced all four calipers and your master cylinder was mounted on the driver's side fire wall, which most are, you would start at the Right Rear wheel, then Left Rear, Right Front, and finally Left front. That is provided you removed all of the calipers and air entered into the system. Make sure after you bleed each wheel you top off your master cylinder. Happy bleeding!