scottroll

Hello. I am a new member to this forum, but a long-time Civic owner. I recently replaced the front brake pads on my stock 1995 Civic DX. After completion, I quickly realized that I had no pedal, which seemed to be a classic case of air in the lines (I had accidentally taken the brake on the FR caliper, so I was sort of expecting it).

I tried to bleed the brake system, using the classic 2 person method, but to no apparent effect. No air or brake fluid came out of the release valve. The fluid reservoir is and has been completely full, no lines were obviously kinked/damaged, and I was having no issues with my brakes prior, so I was at a loss. I took the car to a local shop, where a friend works, to see if they had any ideas. They of course tried to bleed the brakes, on all four calipers, but they had the same experience that I did: no fluid, no air, nothing.

The mechanic said that the Proportioning Valve which distributes the brake fluid could be bad, resulting in no fluid reaching the calipers. This PV is mounted to the firewall, roughly in the middle, and has a number of metal brake lines attached. Is there a way of troubleshooting this valve in order to either eliminate it as, or confirm that it is, the problem? Or are there any other suggestions as to what could be the culprit?

If it is the PV, I believe I can find one at a junkyard for a halfway decent price, but from what I've seen, it would cost around $200 new, so I want to be reasonably sure that it will fix the problem. Any help would be greatly appreciated.

ezone

Did you or anyone else remove the bleeder to make sure that it wasn't clogged? I have had them clog with rust and dirt, and have had to clean the little holes out with a drill bit to get it to work.
Rubber hose ain't kinked now?
Wasn't kinked?
Didn't clamp it off with vise-grips or anything, did you?

Is the problem with bleeding only the one corner that you mentioned, or all 4 can't be bled now?

If you pulled a hose off of the caliper, did it empty the reservoir on one end or the other? It can be a muthafutha to bleed out if the master got air in it.
If that happened, try this:
If the bleeder is not clogged, you could set it up to bleed out and use your finger to cover the bleeder hole while someone pumps the pedal rapidly. This way you can get more volume of fluid moving and probably overcome the air bubble. Once you get fluid to the caliper, then resume normal bleeding methods.

^^^Do it right, this will probably get you going again.^^^





On checking the proportioning valve, you probably don't have any brake pressure gauges to really check the right way, and it would need to be bled out and working anyway.
Your problem right now is getting fluid to flow. If you think the prop valve is the problem, then loosen lines one at a time while someone is pumping (holding pressure on) the brake pedal. Problems with that are extremely rare though, but it IS an old car.


Fluid flow blockages are checked by loosening lines to figure out where the flow is or where it isn't, but you really have to think about it and use strategy. You can't just undo random lines and expect an answer.


That should keep you busy for a few minutes.
HTH

scottroll

Thanks for the reply. I don't think all 4 of the bleeders were checked for clogging, but I know that 1 or 2 of them were checked and were not clogged. There have been no visibly kinked lines, then or now, and I did not clamp any lines in any way.

On all four wheels, bleeding was unsuccessful, no air or fluid came out. When I initially took the brake line loose during the brake job, it released a significant amount of brake fluid, but the level of fluid in the reservoir did not drop, and it is has remained full. Now, even after the normal bleeding procedure is performed several times, you can take the actual brake line loose from the caliper and no fluid comes out. This definitely applies to the caliper from which I removed the brake line during the brake job, but I don't know about the other 3 calipers. I do know that bleeding did not produce any results though.

ezone

Ok......

I might start cracking brake lines loose, starting at the master. Loosen while someone is standing on the pedal..... Wait a sec...


What caused the front brakes to need serviced?
Did the brakes drag badly?


All wheels affected......
I'm thinking there may be a huge problem with the master, and oil contamination would do it.
Did someone dump in something other than DOT3 brake fluid? Rookies and QuickyLubes seem to make this mistake quite often.

The cap of the brake reservoir: Is the rubber all swollen and bloated?


From this article: http://www.croberts.com/Autofailures.htm

Word:
https://www.google.com/url?sa=t&rct=...jiIheg&cad=rja

More:
http://europe.delphi-dso.com/downloa...TAMINATION.pdf


If this is what has happened to yours, you are in for a good time. NOT.




If the fluid is clean and perfect, try figuring out if something is holding the brake pedal slightly applied, like a brake light switch mis-adjusted.....

Loosen the 2 nuts that hold the master by about 4 turns, then see if fluid will move now. Adjust the pushrod inside the booster?



HTH

scottroll

The front brakes were indeed dragging/scraping pretty badly, which I just chalked up to the pads being overly worn, which they were. They had very little life left on them.

To my knowledge, no one has put brake fluid in the car other than me, and I use good brake fluid. The car is still at the shop, so I can't get a look at the reservoir lid, but I will try to get down there soon.

scottroll

**UPDATE**

I just got a call from the shop that I had look at the brakes, basically calling to say that they have given up. This is a shop which claims to have a mechanic certified in brakes. Of course, it's the boss, so who knows if he really knows his stuff. They have been working on it for a couple of days, and claim to have eliminated the master cylinder, brake booster, and proportioning valve as the culprit. They say they eliminated those components by taking certain brake lines loose and seeing that fluid was being pushed through, but there is still no fluid reaching any of the 4 calipers.

They said that the only other possibility is that I got the entire brake system full of air and the entire system has to be flushed, which requires a special machine. They referred me to another shop in town which they claimed had the machine...they don't. But I guess I will take the car to them, or someone else, tomorrow to have them look at it.

Any other suggestions? Thanks again for the help. (Please see my previous reply as well)

ezone

Brake hydraulics are pretty darn simple.
Especially on a car that old.
IF one has a certain amount of understanding.
It ain't rocket surgery.

Now they want to send you to someone with a flush machine?
Sounds like your current "shop" specializes in parts replacing, not problem solving.
I'd suggest you find one of the latter type.

Flush machines didn't exist when hydraulic brakes were invented.
What in the hell did anyone do with a problem back then?

I don't really need to tell you any more about what I think you are dealing with...


Would this help? http://autorepair.iatn.net/

anibis

So the pedal is going to the floor and no fluid is coming out of any wheel, that sounds like a master cylinder issue. I know the shop said they checked but they seem to be part swappers so I wouldn't trust them.

Did you pump the pedal at all when you had the RF brake line unhooked? This would really be the only way for a lot of air to get in the system. If you just unhooked it and saw your error and hooked it back up there wouldn't be much air in the system.

When you first started pumping the pedal after you installed the pads, did you go to the floor or stop half way? The brake pedal never goes to the floor under normal operation and gunk will start piling up at the stop point, more so if the brake fluid has been poorly maintained. If you took the pedal to the floor the piston went through all that gunk and may have compromised the seal against the bore. This has never happened to me but I've heard of it, mostly with older cars.

scottroll

Thanks again to all for your replies:

@anibis:
I did not pump the pedal at all while the brake line was unhooked. I quickly reattached the brake line. While I knew it may have gotten a little air in the line, I certainly didn't think it would have gotten a great deal of air in the brake system, as I told the guy at the shop. I thought bleeding the brakes would solve any potential problem.

The possible scenario you mention with the piston going through the gunk and compromising the seal, and I think I remember reading something similar on another site, you're talking about on the caliper or master cylinder itself? I may have put the pedal to the floor once or twice when I tried test driving it and had no pedal. Thanks.

ezone

That description happens inside the master cylinder, not the calipers.

Normally when it happens, it only allows the pedal to slowly sink to the floor after one of the internal seals was damaged....You can hit the brake pedal and it feels right momentarily, but your foot slowly goes to the floor as you keep pressure on the pedal.
Could be worse than that, but that is what I have seen happen in the past.


Not quite like your description of "suddenly zero pedal and no fluid flow", IMO.
Didn't the parts replacers already replace the master cylinder?

anibis

Yeah I get what your saying ezone....I'm just thinking since the system didn't have any pressure due to the pad change maybe he took the brake pedal to the floor and killed the seals on the first couple pumps.

Maybe the MC was going to go soon and that just put it over the edge. Is it original?

He did say the brakes seemed to be dragging so there was something going on before the pad change.

ezone

I think he meant the pads were either into the squealers, or metal to metal. I sensed he meant "worn out and making a dragging noise"....

I meant wouldn't release or applying by themselves, like as in a master problem or pushrod length problem. Blocked ports to the reservoir.

Bad description on my part, I keep forgetting most of the people on here don't deal with cars like I do.