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Brakes half working

5K views 19 replies 9 participants last post by  Leeann_93 
#1 ·
Hello everyone,

The brakes on my 1993 Chevy Astro 2WD suddenly stopped working today. :-(

Please help / point me in the right direction...

[I'm not sure if the following has anything to do with the break pedal not working but I mention it anyway: during the past 12 months the parking break has gradually lost its power, has almost no effect now.]

This is what happened today, chronologically:

1. Left home 13:00, breaks were OK.

2. Went to the car wash 15:00 (fully automated). The instructions mentioned that the brakes may be weak for a few miles after the car is washed...

3. Drove out of the car wash and I almost couldn't stop (had to push the pedal real hard/deep). Never experienced this before. Brake light was constantly on.

4. Popped the hood and to my horror BOTH break fluid containers were empty! Little bit of fluid in the drain where it disappears into the system...

5. Filled both containers 3/4 with DOT 4 since I couldn't get DOT 3. Drove off. No improvement. Brake light still on and I had to push the pedal hard/deep in order to stop.

6. Checked the containers again after 10 miles. Small container empty. Big container OK.

7. Looked under the van but couldn't see any fluid dripping / disappearing (plus hard to tell after a wash).

8. Filled up the small container again, drove up/down the street (5 minutes).When pumping the pedal, it gets hard but breaking is still weak. Checked both containers again, result: small container half full, big container OK.

What can it be? Never had a brake problem before and never had to refill breaking fluid.

Could the high pressure under-wash have damaged the brake system? I suspect it's leaking, but where, or can it be something else? Anything more I can do to diagnose it? All help is appreciated. Thanks.

Allman
 
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#2 ·
Brake fluid has to be going somewhere, no mystery there. Look for leaks, you will find a ruptured line somewhere or a leaking wheel cylinder.

The parking brake is cable operated but could be because rear drums/shoes worn/out of adjustment.

The loss of fluid is priority, find and fix that then look at brake wear front/rear.
 
#3 ·
The first thing is to find out if it is leaking, could be a bad wheel cylinder and leaking into the rear drums, in which case your brake shoes are toast. Could also be a brake line, a rusted steel line or a leaking rubber line. You could also have been low on fluid and now just have air in the lines and you need to lead the brakes.
 
#4 ·
Thanks for quick answers.

I looked under the van, touched some break lines but couldn't see/feel any leakage. How to check/see if it's a leaking cylinder? Do I have to take the tire off? What did you mean by "lead the brakes"?

Thanks.

Allman
 
#5 ·
lead= bleed
you may need to pull the wheels and rear brake drums. You may want to fire it up and have someone apply the brakes while you crawl under it looking for a leaky line. The brake lines run over the gas tank where you can't see them and can rust out. If you don't find any leaks get a big bottle of brake fluid and bleed the system, if your not sure how search the forum, you'll find the procedure.
 
#6 ·
Thanks again. I'll see what I can do.

Forgot to mention that even though the fluid containers were empty (let's say 2% full), I only had to add a little bit of fluid to make them 75% full. I think I added like 5 ounces in total (1.5 dl) so the system was far from drained (I'm guessing there must be at least half a gallon of brake fluid in it, or what?).

Question: what is the difference between the small and the big container/reserve? Front/rear?

Found a tutorial: http://answers.yahoo.com/question/index ... 344AAazoyF

Allman
 
#7 ·
Even though the resivoirs weren't comply empty you could still have and probably did get air in the system. Fluid, such as brake fluid doesn't compress, air on the other hand is very very compressible.
I read the tutorial, that's it, right (passenger side) rear, left rear, right front, left front. You don't need to get all 4 wheels off the ground at once, you should be able to easily do the rear without pulling the tires or jacking it up, but the fronts will be easier with the tires off, you may have ot turn the steering wheel one way or the other to get better access to the bleeder.
I just yell to my helper, PUMP!!! HOLD!!! keep a close eye on the reservoir that it doesn't run low. I pump 3-4 times after not getting any more air bubbles. If your brake fluid is nasty dark gray, you should think about doing a full flush, just work each one until you have fresh clean fluid coming out. One thing people don't think about or maybe know is brake fluid naturally absorbs water, which isn't good.

Correct on the different size reservoirs.
 
#8 ·
Thanks for the follow up and comments!

Brake fluid is definitively dirty, small particles/black-greyness came up when I filled the containers yesterday. Haven't been changed or refilled for years so I guess a full flush is the best thing to do.

I'll check it again today and look for puddles / leakage, couldn't see anything yesterday evening...not sure if it's actually leaking (though the disappearing fluid from small container indicates that) or if it just sucked in air since both containers were empty.

Questions:

1. Should the van be running when the helper pumps and holds the brake?

[It was mentioned that it's not necessary to take off the rear wheels. Great.]

2. Please look at the attached (old) picture of the rear left wheel - is the bleeder screw visible on the picture? (or is it on the other/front side?)

Allman
 

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#10 ·
You might want to spray the bleeders with some penetrating oil like PB blaster, they look pretty nasty. With the rust under there, if you don't see any leaking I'd pay close attention to where the lines pass over the gas tank.
 
#11 ·
Thanks for the confirmation.

Located the bleeder screw but it won't budge. I was just about to apply WD40 when I saw that my poor van is leaking! :-( At least now I think I know where and what the problem is: brake fluid seems to be leaking from behind/above the gas tank, somewhere... (good guess Jansen) Hard to tell exactly from where 'cause the line suddenly disappears and I can't see what's going but I'm sure it's coming from up there. Of course, it had to be a difficult case. :roll:

Regarding the disappearing brake line: Why did they make it like that? To protect the line? But it's out in the open all the way until it reaches the tank, why is it suddenly squeezed in up there beyond reach...?

Pictures attached, please have a look...

Is there a way to fix this quickly or does the tank have to come off? Most things/screws are quite rusty, my guess it's a minefield...

Allman

[EDIT: I wrote break(ing) instead of brake(ing) for a while, sorry... :-]
 

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#12 ·
Your not the 1st. to have it fail there. Some people of gotten enough new line to re route the line around the tank so they don't have to remove the tank. Spray the bleeders with PB Blaster every couple/few hours until you can get them loose, you should pick up a set of tubing (flare nut) wrenches with one that fits the bleeders. Search the forum for brake lines, there should be a write up on how to do it. You can get brake line at the parts store. You'll also need a flaring tool, which you can probably barrow or rent from the parts store.

Tubing wrench

 
#13 ·
Allman,

I feel for you.. When I had my gas tank down last November for a fuel pump change, I saw that my rear brake line/pipe was very rusty... and it was weeping some fluid from very small pin holes. So I was lucky and replaced it with the gas tank removed.

For my 1999 Van,
I purchased some brake line/pipe form the local parts store (1/4" tubing x25 feet)
and rented the brake line flare tool...
the front side of the rear brake line/pipe has a large 1/2-20 thread steel nut (to the ABS unit)
the rear side of the rear brake line/pipe has a small 7/16-24 thread steel nut (to the rear axle junction block)

The biggest pain was to release the rear line from the ABS unit.
I cut my flare nut wrench in half, so I could have a short throw on removing the nut on the ABS unit.

Good luck,
Herminator
 
#14 ·
If you can get a crowfoot socket in the size required, it makes working on the EHCU a bit easier. I have a full set of

them in std and met. Every once in a while, they come in handy, and keep me from saying too many bad words.

Uncle Bob
 
#17 ·
Hello and thanks again for all the help guys.

Here is what happened last week (Easter):

Due to lack of tools and skills/experience, I let it be and took it to the service. They claim they spent 6,5 hours in total (getting rid of the rust, taking down the tank, replacing the broken line, bleeding the system, putting it back together and testing). They replaced the line from a junction near the driver seat all the way back to the T-splitter above the rear axle.

Thanks to the wonderful people on this forum I could at least show them exactly what was wrong and what needed to be done. Big thanks again!!

I attached some pictures of how it looks now. I hope it'll be OK for a long time...

Thanks again.

Allman
 

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