305RSlc

Well my brakes were shot so I decided to fix them up a bit. I just did mostly OEM stuff for now, good old Autozone rotors, pads, bearings, calipers, seals, and super tech DOT 3 fluid. I did splurge a little and get Earl's SS lines for the front. After I redid the brakes though, front disc only, I am very disappointed with how soft the pedal is. You almost have to push it to the ground before the car feels like it's being stopped. After redoing everything, I had my brother help me bleed them. The way I did this was, with the car off, had him pump it up 3 times then hold it down and I just opened the bleeder screw enough for fluid to come out then closed it again while he kept the pedal down to the floor. Did this 3 times on each side with the car off, starting with the pass side first. Then I repeated the process with the car on. Is this the right way to bleed the brakes? Or could my soft pedal feel be from something else? Just kinda annoyed cuz I put $200 into redoing my brakes, and it feels like I went two steps forward and three steps back. Thanks for any help.

Apeiron

Did you see any air bubbles coming out with the fluid?

305RSlc

Well that's why I asked if I bled them correctly. I didn't actually use any kind of hose that ran into a thing of brake fluid it see if it had air bubbles in it, I just opened the screw, then closed it again. I just bought a little $5 brake bleeding kit and I plan on rebleeding everything tomorrow with the hose stuck in a cup of fluid to be sure. So improper bleeding more than likely the issue here?

Yrap

Yeah i would try to re bleed the system maybe get a bleeder pump make sure your doing them in the right order to the one farthest away from the master cylinder first then next closest and if it still dosent work i would check the parts they gave you make sure every things right i dont trust those auto zone guys at all

305RSlc

Nor do I, but I had to be cheap this time and use those parts. It was funny cuz they gave me the wrong outter bearings, they didn't even fit in the rotor. Kinda sad....oh well.

Yrap

Yeah i worked at a national auto " A small car parts store chain around here" with FarFire70 and half our customers were people from auto zone or Pepboys that had ether gotten the wrong parts or were getting the run around about trying to get some thing. I don’t know how many time we got calls from Pepboys looking for part or asking us what parts were right

anondude13

1. get a helper
2. get helper to press brake pedal
3. open bleeder screw and watch for bubbles
4. close bleeder screw
5. get helper to release brake pedal
6. repeat 2-5 until you are confident that the line is air free

305RSlc

Yeah, I did all those except the last part of #3. But I do have a piece of hose to slip over the bleeder screws to watch for bubbles now, so hopefully that will rectify the problem. Thanks

anondude13

I forgot to mention. Don't forget to watch the reservoir and keep it full at all times.

anondude13

DP

305RSlc

Welp, rebled my brakes today, and there was a VERY SLIGHT difference. There was like 1 bubble that came on out each side. However, my brakes still feel soft and spongy. I can feel them gripping slightly earlier than before, but it's nowhere near what I was hoping for being that these are all new components. I have to push the pedal about 1/2 the way down for the car to even feel like it's slowing up. Any other things I should check? Also, what about seating brakes properly? I kinda babied them at first, did maybe one or two panic stops from low speeds after they were replaced. Could improper seating have this "soft" pedal affect?

Wadebryant

Just went through this just recently too... I had to completely bleed the entire brake system (4 times) before getting all of the air out. Most likely you still have air in your system. Follow the advice that r3pp3r lists. One trick that I use to know that fluid and air is being purged is to run a rubber hose from the bleeder screw into a jar 1/2 filled with brake fluid. Have your assistant push the pedal down and hold it, crack the screw to release pressure, retighten the screw after pressure is released, then have your assistant let up on the pedal. Repeat the process over and over again at every corner starting at the furthest.

RB83L69

Sounds to me like the MC was allowed to run dry while you were working on it; and now, there's air in it. That being the case, you can bleed it at the wheels from now until Judgement Day, and it will NEVER get any better.

If you look at the MC, you'll notice that the place where the lines enter the MC, isn't the hgihest point of the MC. Which means, if it gets air in it, it will get trapped up in there, above the line fitting, and will NEVER EVER come back out. The ONLY WAY to fix it, is to "bench bleed" the MC. You can do that on the car if you're real careful. Take the MC loose from the booster, and detach the prop valve from its bracket so that the whole assembly can be tilted forward to where it's level (it's easier if the rear of the car is way up in the air); and with a screwdriver or something, gently diddle the MC piston in and out, while watching the little fill holes in the bottom of the reservoir. I'll bet you'll see a couple of cc worth of air bubbles come up out of there.

Don't forget, brake fluid eats paint, real quick, and real ugly. DO NOT allow ANY brake fluid to touch your paint!!! You will regret it.

MrDude_1

tip for that:

keep some WD40 handy along with some spare clean rags..
if (when) you get some brake fluid on paint, wipe it, turn the rag over, spray the area with WD40 and wipe it again....

if you do that RIGHT AWAY, you wont have a prob.. wait 5mins to do it, and you will.

305RSlc

You are exactly correct, sir. When I changed the pass side, I undid the hose and just let all the fluid drip out while I repacked the bearings and set the seals in the rotors, and the MC was run dry when I did that. I didn't even think about air being in the MC though. Other than what you outlined, which seems WAY too easy for me to screw up, is there another way to get air out of the MC. Aren't there pressure bleeder kits or something that forces brake fluid into the MC to be sure no air is in it? I think I remember seeing it on Two Guys Garage or something, but the MC was out of the car. Or should I employ the help of a shop to be sure it's done correctly? Thanks for that tidbit of info.

RB83L69

No. If "force" would work, then the many hundred psi of pressure that exists in the brake system in normal operation, would cure it in no time.

Air rises to the top. Period. Force or no. You gotta give it a way out, or it will stay there forever.

"Bench bleeding" is typically done in a vise. It involves clamping the MC to hold it level, and doing more or less as I described. That's what they showed on the show. It's the standard procedure that you're supposed to use when changing one.

The trick when doing the sort of thing you were doing, is to avoid letting it run dry in the first place. The best thing I've found for dealing with it is a golf tee. Stick it in the end of the brake line.

Apeiron

Great for plugging vacuum hoses too.

305RSlc

Thanks, RB83L69, for all the info. So basically all I need to do is get the MC level, and use something to simulate the brake pedal by moving the piston in and out. Do I do this with the MC resevoir completely full, or should I take a bit of fluid out to make it a little easier? Thanks again for the help.

RB83L69

Probably less messy if it's not all the way full.

HalfInchWrench

Wouldn't parking on a nice steep hilll or jacking the car high in the back acomplish the same thing as far as bleeding the air pocket in the front of the MS? My GM shop manual does not mention anything about that even tho I can see how it could be a problem. It says to just bleed it from the front line a few times by slacking/tightening the line while someone presses and holds the pedal and then do the rear line.

RB83L69

Yes, in theory, it would accomplish the same thing; but I believe you'd find it VERY DIFFICULT to work on a car on an incline of that much slope (about the angle of your roof). That's why I suggested lifting the rear as high as he could get it; even though it's totally impractical to level the MC that way, you can at least get a good part of the way, and not have to **** on the lines so much.

You'll also find that the GM service manual instructs you to bench bleed the MC before you put it on... at least, I seem to recall that mine does; as do all the instruction sheets I've seen come with new MCs. Once you do that, the other is adequate.

HalfInchWrench

Some of the messed up shapes you have to get in to work on a car, I would gladly take the side of a mountain! Hee and it's true too. Some things are realy bad, the MS isn't one of them.

The genuine GM shop manual I have only mentions bleeding it thru the two line fittings OR on the bench. It's for the model year 88. That was the oldest one I could find at the time. Back around 97 or so I bought it. I have the Hayes and Chilton ones too but they suck. They tell you to bleed the MS but don't tell how. It didn't say a thing about the angle it's at. I can see how that woud be important tho.