Brakes Still Mushy after bleeding

[MrTrouble]

Hey there all... I have a '99 Fleetwood Southwind 36Z on the F53 Chassis. I replaced my front brake pads earlier this year, and I replaced the rear rotors, pads and calipers about a week ago. I've bled the brakes several times, but they are still soft when I first press the pedal. I few quick pulses (pumps) on them and it is nice and firm, but I can't get past the mushiness of them.

My rig has the boost assist on it, so, even with the key off, you hear the power kick in when you press the brake pedal. So after doing the standard "pump, pump, pump, hold" and open the bleeder; I decided to try and leave the bleeder screw open while the wife pushes the brakes over and over again. I did this with the drain hose in a bottle with brake fluid in it, the tip of the hose constantly submerged.

Does the boost assist system need some sort of bleeding? I thought I read somewhere that it was self bleeding though. Can't quite get my head around what I may be missing.

Thanks,

Juan

[CountryB]

Brake bleeding can be tough. Some of the chassis have lines that run up and down and coil around. Getting all the air out can take a while. Always bleed from the wheel furthest from master cylinder first working toward the master cylinder. Since you only replaced the front brake calipers, you should not have any air in the rear lines (unless master cylinder went dry).

Your manual method - pump, pump, hold, then open bleeder, let pedal drop, then close bleeder, let pedal up - and repeat is correct "two-person" manual method. Opening the bleeder and keeping it open (with bleeder hose submerged) while pumping pedal will not work.

There is a spring loaded "speed bleeder" valve available for most cars and trucks. It make the job real easy. I used this on my truck recently as I was having hard time even with my vacuum bleeder kit. With this kit you stick the hose on the bleeder screw, stick the other end in a jar, crack open the bleeder screw and then just pump the brakes (topping off fluid level as needed).

To see if this style is available (you would just need to determine the bleeder screw size and threads per inch (like 1/2-20) to see if there is one that will fit your coach (as your specific coach model is not likely to be listed. But your bleeder screws are probably same size as used on Chevy 3500 or Ford Superduty or such).

Introduction - Speed Bleeders - Russell Performance Products

[MrTrouble]

Thanks Mike,

I actually replaced the front pads only. I replaced everything in the rear, so I did have to open the line.

My vacuum pump didn't work at all. I got quite a bit of air out using the submerged line and continually open bleeder. I will have to look for some speed bleeders too, however.

Thanks,

Juan

[Waiter21]

When I bleed, I make sure the bleeder is lose, then snug it back up. I then attach a hose to it,

I have the DW press and hold the pedal, Using a wrench, I open then close the bleeder. When I do this, I get a burst of fluid/air out the hose and the pedal goes to the floor. She holds it to the floor until I tell her to release it. We repeat this until the burst has no bubbles or air in it. I start the farthest away first. This "burst" generally will clear any high spots in the lines and push that air pockets toward the bleeder.

[MrTrouble]

Originally Posted by Waiter21

When I bleed, I make sure the bleeder is lose, then snug it back up. I then attach a hose to it,

I have the DW press and hold the pedal, Using a wrench, I open then close the bleeder. When I do this, I get a burst of fluid/air out the hose and the pedal goes to the floor. She holds it to the floor until I tell her to release it. We repeat this until the burst has no bubbles or air in it. I start the farthest away first. This "burst" generally will clear any high spots in the lines and push that air pockets toward the bleeder.

Agreed, I've bled brakes on many different applications for years. I've used 3 different techniques on my Southwind, all of which have yielded results.

When the wife presses and holds the brake pedal, it will go to the floor after 3 or more presses, albeit very slowly, no matter how much bleeding I've done. I don't have any bubbles coming out of any lines. I did start from rear pass, to rear driver, to front pass to front driver. I don't believe that we can bleed the master cylinder on these things.

Does the fact that there is a boost system on the brakes have anything to do with it? Power steering fluid is at the appropriate level.

Juan

[Waiter21]

Does the fact that there is a boost system on the brakes have anything to do with it? Power steering fluid is at the appropriate level.

It shouldn't..

[cfowler55]

If you feel you have bled all the air out look for a mechanical issue. Watch the caliper piston movement as your helper depresses the pedal. If something is pushing piston back when pedal released you have to displace enough fluid to make the pads re- contact rotor correctly before clamping force takes effect.

[twinboat]

Crawl under and make sure the bleaders are on the top of the caliper and the line goes in the bottom, on both sides.

Some places are suppling the wrong ones and some folks are putting the right caliper on the left side.

[dan-nickie]

Never pump the brakes with a bleeder open

Press on break
Open bleeder, close bleeder
, let off break

[Hgrace56]

Some vehicles like my 76 corvette must be power bleed to work correctly. It has to do with lengths and elevations of master cylinder lines and calipers.