Brake Help

[sLADe781]

Okay guys, I need help. My buddy's '93 Honda Civic's brakes went out on him. He was entering the freeway and his brakes just lost pressure and he had no way of braking so he ran into those yellow tubs on the side. So question: what can it be? I can't go out there until Saturday so that gives us some time to try and figure out what happened.

1st thought: his brake fluid was empty but he popped it open and it was topped off. However, I think it may still have something to do with the brake cylinder system (not sure if there's a master and a slave for the brake system) seeing that when my clutch slave cylinder went out, the master cylinder was topped off but I still had no pressure. So yeah, maybe the brake cylinder somewhere? Are there more than 1?

2nd thought: I was thinking that maybe one of the brake lines has a hole in it. If so then it would be obvious as there will be fluid around the hub, right?

3-maybe there's just a clog somewhere!?! Afterall, his car's like a '93 or something so it's highly likely, right? So if that's the case then just do a thorough flush on all 4 maybe?

4-brake pads...but I'm thinking that the pads would be squeeking if it was gone and that it would be hard to stop, not lose complete pressure.

5-he said he thinks it's the heat because it was super hot today but I said I don't think so. Not sure if heat could cause a complete lost in pressure...

Well, let me know what you guys think. Again, all that happened was that he lost complete pressure in his brake pedal and could stop.

Thanks.

[AudioGuy93DelSol]

If he completly lost pressure than it was proably a hose that burst or a crack in a hard line. Pads, heat, nor clogs will cause a complete loss in pressure. Check all the lines and look for damage.

[sLADe781]

Okay, here's something weird that happened...he has pressure again. No bleeding, no replacing of any hose or parts or anything and the pressure just came back. Any ideas? Should we still take things apart? If so what? I'm about to head over there pretty soon but if you guys have any ideas in advance that would be great. Thanks.

[songsandstars]

It's not the heat. Bleed em, Flush em, and then fill em. Sounds like a clog to me. If a hose was busted then he wouldn't get his pressure back. Check the calipers and everything while you're in there too. Make sure they're movin easily with some grease. My brake tube burst once cause of that. Good luck though, brakes can be a bitch to fix.

[sLADe781]

Bad news...we weren't able to take off the stupid rear drum because we can't find the right bolt/screw and I broke off the bolt that the lug nut screws on to because it was stripped somehow. Hard to fix? How bad is it for a car to run on 3 instead of 4 lugs???

[johnb16a2]

Originally Posted by sLADe781

Bad news...we weren't able to take off the stupid rear drum because we can't find the right bolt/screw and I broke off the bolt that the lug nut screws on to because it was stripped somehow. Hard to fix? How bad is it for a car to run on 3 instead of 4 lugs???

It's an easy repair and you can run on three studs for a little while if you have too.. The stud is pressed into the hub and to replace the stud just smack it with a hammer to get it off the hub (support the hub with something to prevent bending the hub or damaging the bearing, better if you can get some kind of press to push it off). You can get a replacement stud at most any autoparts store. Just put the stud in the hub best you can, put on the wheel (or stack some washers), tighten the bolt, and the stud will be pulled into the hub.

As for the brake problem I agree with the others there is definitely something wrong, perhaps several somethings. Could be a line leak, bad master cylinder (leaking into the booster), leaky wheel cylinder/caliper, collapsed hose, seized brake causing the fluid to boil, etc. But bleeding the system is a good first step. GL

[sLADe781]

Well, all we ended up doing was bleeding the system. We took off the wheels and checked the hose, wheel cylinders, and drums but nothing was visibly leaking or cracked. So that was pretty damn annoying. Remember the lug bolt that I broke? Well, luckily there was enough bolt left so we were able to buy a new nut and just used that to hold it in place for the meantime.

Aside from that, the bleeding did absolutely no good as far as the feeling of the brake pedal goes. I mean, it stops but I still think there's some type of air getting into the system or the system just has air still because there's still a bit of play before it actually stops. Can the brake system be gravity bled the way the clutch system can? Because if it could then he could do it by himself again...although it is a bit "scary" since two of the nipples were semi-stripped. Yeah, he's in college and I can't drive out here every weekend so you know...

So yeah, feeling a bit damn depressed seeing that I feel like I caused more harm than good.... :o/

[johnb16a2]

Originally Posted by sLADe781

Well, all we ended up doing was bleeding the system. We took off the wheels and checked the hose, wheel cylinders, and drums but nothing was visibly leaking or cracked. So that was pretty damn annoying. Remember the lug bolt that I broke? Well, luckily there was enough bolt left so we were able to buy a new nut and just used that to hold it in place for the meantime.

Aside from that, the bleeding did absolutely no good as far as the feeling of the brake pedal goes. I mean, it stops but I still think there's some type of air getting into the system or the system just has air still because there's still a bit of play before it actually stops. Can the brake system be gravity bled the way the clutch system can? Because if it could then he could do it by himself again...although it is a bit "scary" since two of the nipples were semi-stripped. Yeah, he's in college and I can't drive out here every weekend so you know...

So yeah, feeling a bit damn depressed seeing that I feel like I caused more harm than good.... :o/

The brake system can't be gravity bled as far as I know, and replacement bleeders (I assume that's what you're talking about) can be found at most auto parts stores.

Since bleeding the system didn't really help much, I'd wager the master cylinder is bad, my 89 did something similar, the pedal would be fine most of the time and once in a while the pedal would get really soft and had little stopping power.

Nah, don't blame yourself, you are trying to help your friend and you're working on an older car, stuff like that happens all the time. GL

[tomogchi]

I dont know the exact name of the zirk valve, But they make one to weres it will bleed by itself, but not allow air back into the lines (got a lil roller ball ont he end), that may work out a little bit better when you go to replace (if you do) the zirk valves.

Id put money on the MC, most likely a ripped seal somewere that is causing fluid to be tranfered form side to side on the "overgrown" slide.
But i would think that would be an all or nothing thing.

a quick way to maybe find out if your MC is bad (I dont know if this would work, but it sounds like it might?), is a vacuum bleeder. Undo the zirk valve, and attach the vacuum bleeder to it. keep the vacuum going, without touching the brake to see if brake fluid slides by.

Bill

[Tofuboy]

When was the last time the brakes were bleed before the accident happen?

Does the car usually being driven aggressively?

Was he driving it aggressively when the accident happens?

Was the brake fluid dark when you bleed the system, any rust in the fluid?

I believe it doesn't have an ABS system and it's a diagnal split.

Lift the car up and starts the engine and put it in neutural, have one person step on the brake padel and another try to turn one of the rear wheel and see if the brakes holds, do it to all four wheels (starts with the rear wheels) and see if anyone of them are not holding. If there is a wheel that doesn't hold then you found the circuit that has a problem.

Check each and the whole brake lines (especially at the connections) for leak and wet spots, not just behind the rotors and drums.

If you don't have any fluid leaks at all and all four wheels hold, my guess is most likely the cup seals inside the master cylinder are damaged

[mab6680]

my brake pedal droped to the floor the other day with no brakes at all i changed the master cylinder now it stops but it doesnt grab intill the pedal hits the floor after i changed the master cylinder i manually bled the system but still no pedal so i i vacum bled the system the back brakes bled fine but the front would not bleed with the vacum i would just get a gurgle and a little fluid any clues why the pedal fell to the floor or why i cant get the front brakes to bleed properly