Question on brakes (bleeding)

**TokerM** · 09-28-2010, 08:52 PM

As I've mentioned in other threads, I'm taking an auto mechanics class at a local vo tech (this becomes pertinent in a sec.)

I wanted to paint my brake calipers tonight (a bit time consuming, I only got the fronts done

) I pinched off the brake lines, pulled the line and took off the calipers. Cleaned and painted them and put them back on. Seems I missed a crush washer on the passenger side, but once we figured out that it was leaking, I found the washer and replaced it. Bleed the brakes on the passenger side:

"Hit the brakes... release... hit them again... release... blah blah blah."

The professional that is "teaching" is getting the look that I hate to see on a mechanics face, tells me he's not getting any fluid out, and to try turning on the engine.

I turn the car on, mash the brakes a few times and all seems fine. (passenger side.)

Go to the drivers side, and he can't open the bleeder valve (rusted shut.) He said we'll try bleeding it from "another orifice" (the bolt.) He seemed to feel everything went ok bleeding them out.

Once I got the car out of the bay, the brake light was on and there was almost NO brakes (mushy brakes would be the understatement of the year... 10-0 in about 100')

I was told all I needed was fluid, there was none at the shop.

I stop and buy fluid (yea for downshifting and e-brakes!) which kindly makes the brake light go away... Still INSANELY mushy brakes. I limped home.

Two questions:

1. Does it sound like I just need to re-bleed the brakes now that I filled the fluid back up? (she drank a whole bottle of dot-3) Or, is there the possibility of a real problem here?

2. The mechanic told me the the bleeder valve stuck on the drivers side could be a real problem. Like... "You'll need to buy new calipers."

New calipers just for a rusted bleeder valve?!? I'm really new to auto-mechanics, but I am a mechanical designer, I can figure out most mechanical systems, and the bleeder valve looks just like plain old zirk fitting. Can't I just hit this with penetrating oil, and tear into it? If it brakes, extract it and clean the tap, correct?

**Mr. Luos** · 09-28-2010, 08:57 PM

Any air gets in.....ALL corners need bled.

The bleeder valves are cheap. They should come loose eventually. May need a new one though.

**0rion** · 09-28-2010, 09:35 PM

you still have air in the lines. You can replace just the bleeder valve as long as you don't break it off in the caliper then it becomes a pain in the ass to get out. Hose it down with pb blaster and let it sit for a bit before trying to get it out. Just to be on the safe side bleed all the brakes starting the furthest away from the master and working towards it. Don't run the master dry so keep topping it off as you go. You can buy or make a self bleeder but it's usually just as quick and easy to have someone pump the brakes while you work the bleeders.

**Too Fast** · 09-29-2010, 02:58 AM

Yes you still have air in the lines. If the bleeder valve won't turn, try letting it sit soaking with some penetrating oil for a couple days, keep soaking it. If it still doesn't come open, and breaks, yes you could drill/tap it, but it would be easier just to replace the caliper. My bet is all the air is in that caliper/brake side, if the other bled ok. I'd start there, since you didn't open anything on the rear, you shouldn't have to bleed that to get air out, none should've gotten in unless you ran the master cyl empty/low while bleeding. I've had some success bleeding them the way the instructer was trying to, by loosening the caliper bolt and tightening it before the person in the car let off the pedal.

I've been doing brakes for over 25 years, if I am only changing front calipers, I've only had to bleed the fronts. Assuming, of course, nothing else has been touched and the mc never went dry.

**pajeff02** · 09-29-2010, 03:12 AM

Do yourself a favor. As a future mechanic go spend $30 at the parts store and pic up a Mity Vac. They work great for bleeding brakes and clutches and can also be used to siphon fluids out of power steering pumps and whatever. Also, it is not a great idea to "pinch off the hoses". If you need to remove a caliper, either plug the end of the hose or remove the hose too and cap off the brake line with a rubber vacuum cap.

**JayTA98** · 09-29-2010, 04:22 AM

yup sounds like you have air. I was also told by a friend (Orion or Cutlass can quote me on this) that if you open all the bleeders and you keep adding fuild to the reservoir after a few mins all the bubbles are gone and just close the bleeders. It kinda makes sense but not sure if it works since i haven't had to bleed my brakes.

If you can't get that bleeder off get you a new caliper but like most of the guys mentioned you can get that bleeder out, you just have to play with it.

**pajeff02** · 09-29-2010, 08:14 AM

Originally Posted by JayTA98

yup sounds like you have air. I was also told by a friend (Orion or Cutlass can quote me on this) that if you open all the bleeders and you keep adding fuild to the reservoir after a few mins all the bubbles are gone and just close the bleeders. It kinda makes sense but not sure if it works since i haven't had to bleed my brakes.

If you can't get that bleeder off get you a new caliper but like most of the guys mentioned you can get that bleeder out, you just have to play with it.

I have never been a fan of gravity bleeding a braking system as I am not convinced all the air pockets will be removed. However, if done this way, I would do it for quite a while. Not just a few minutes.

**0rion** · 09-29-2010, 09:15 AM

yeah, you can gravity bleed the calipers but it's by far not the best way to do it. It's time consuming, messy, and not near as capable of getting the air out as forcing the fluid through there.

**TokerM** · 09-29-2010, 02:16 PM

The bottom line...

I was able to get the bleeder loosened without breaking, but the threads were shot. Tried a couple spare bleeders, but the tap in the caliper was shot too.

Now I see why I was told "new caliper." Aluminum and steel bolt-connections are a real mother!

One new caliper later... All's good and I can stop again!

Well... I wanted to learn brake systems... careful what you wish for... I think I'm going to leave the line connected on the rears and simply mask it all off

I'm now debating on what I want to destroy next week... Shifter (MGW short throw,) CAI or change plugs/wires (the plugs/wires scares me... really tight in there...)

Thanks for the help guys!

**pajeff02** · 09-29-2010, 03:54 PM

I painted all of my calipers without removing the lines. A little newspaper and tape, or aluminum foil, really works well. I also found that a cap from a can of spray paint will cover the caliper piston almost perfectly. You just need to contour the cap with a pair of scissors to get the fit right.

**Cutlass** · 09-29-2010, 06:24 PM

Auto technician's top secret alternative to pinching off brakes lines.....

ReadY?????

Before taking anything apart, jam a long extension(or block of wood, pry bar, etc) between the seat and the brake pedal. Move the seat forward, use your foot to put a lot of tension on the brake pedal. Once you take off the brake line, only a small amount of fluid will come out and it won't drip more then a few drops after that. The reason is, the holes between the master cylinder and brake fluid reservoir are blocked off so it won't let the fluid gravity bleed through the system while your working on it. Its like putting your finger over the end of a straw then pulling the straw out of your soda pop. the soda stays in the straw.

**pajeff02** · 09-29-2010, 06:28 PM

That's good info -- never done that before, nor have I heard of it. Thanks Cutlass!

**TokerM** · 09-29-2010, 06:45 PM

@Cutlass

**edit**

how rude of me... One for Jeff too on the paint cap, I have tons of them around for mixing model paints!

**Too Fast** · 09-30-2010, 02:21 AM

Originally Posted by Cutlass

Auto technician's top secret alternative to pinching off brakes lines.....

ReadY?????

Before taking anything apart, jam a long extension(or block of wood, pry bar, etc) between the seat and the brake pedal. Move the seat forward, use your foot to put a lot of tension on the brake pedal. Once you take off the brake line, only a small amount of fluid will come out and it won't drip more then a few drops after that. The reason is, the holes between the master cylinder and brake fluid reservoir are blocked off so it won't let the fluid gravity bleed through the system while your working on it. Its like putting your finger over the end of a straw then pulling the straw out of your soda pop. the soda stays in the straw.

Yup. Works fine for me, but I've seen other dumbasses try it, only to leave the brake lights on too long, battery went dead, they lost the security code for the radio, epic fail! Gotta love thiefs, if it weren't for them we wouldn't have to have security codes!!!!

You don't necessarily have to really push down the brake pedal hard for this trick to work, all you need to do is push far enough to go past the holes in the mc.

As for gravity bleeding, I've done that for years with a lot of success. I'll open the bleeder on the new caliper/wheel cyl or whatever part I worked on, then while I'm working on the other side let the gravity do the job. Make sure the mc stays full, shut the bleeders off, pump the brake pedal a few times, open the bleeder once more to let a few more air bubbles out, close it, then done.

**JayTA98** · 09-30-2010, 12:02 PM

Originally Posted by 0rion

yeah, you can gravity bleed the calipers but it's by far not the best way to do it. It's time consuming, messy, and not near as capable of getting the air out as forcing the fluid through there.

Thanks for the clarification guys.