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-   -   brake light staying on... (https://67-72chevytrucks.com/vboard/showthread.php?t=617400)

jasonroman 02-20-2014 09:43 AM

brake light staying on...
 
long story short...
yesterday i almost took the suburban through the garage door. not because of lack of brakes....ice. prior to this brakes where good to go. slight pull when braking at times... so anyway. i slide on a patch of ice due to the idle being stuck or something and engine and truck basically wanting to just keep going.
well after the stop. the light is on.
pedal is soft.
and light is on.
fluid level looks fine.
any ideas?

donut 02-20-2014 07:36 PM

Re: brake light staying on...
 
Crawl underneath and start looking.
Sounds to me like you lost hydraulic pressure (soft pedal, warning light.), Could be a pinhole in a steel line, wheel cylinder, caliper seal, rubber line, or even a seal in the master, though I'm not sure if the master will pop the light, don't remember.

IMO, start checking one end to the other. If you can't find it. have someone hold the brakes and look again.

jasonroman 02-23-2014 05:42 PM

Re: brake light staying on...
 
well today i had a chance to look at truck. i had my son help me attempt to bleed the brakes..hoping it was just an air issue. well in the process while under truck i happend to hear fluid as he would press on the brakes... found a hole in the metal line under truck.
ran to auto parts. and i was able to cut out a section and repair/replace.
the light is still on and the pedal is still smushy. maybe not as bad as before but still not like it was prior to garage door.
i also was able to shear off the bleeder screw on the front driver side. so this now has me wondering if i were to go out tomorrow and try and bleed the system again will i have a problem because of that front bleeder screw being gone??

imjeff 02-23-2014 05:50 PM

Re: brake light staying on...
 
How did you "cut out a section and replace"? What did you use to replace it? Was it a wear hole or a corrosion issue? I would replace that entire section of line at minimum. If it's not an obvious mechanical damage issue I would replace all the lines. It's actually not a huge job and you will know what's good when you finish.

Jeff

jasonroman 02-23-2014 06:09 PM

Re: brake light staying on...
 
Quote:

Originally Posted by imjeff (Post 6540508)
How did you "cut out a section and replace"? What did you use to replace it? Was it a wear hole or a corrosion issue? I would replace that entire section of line at minimum. If it's not an obvious mechanical damage issue I would replace all the lines. It's actually not a huge job and you will know what's good when you finish.

Jeff

my guess is a wear hole. not sure why me slamming on brake to keep out of garage would blow it out??
i used a pipe cutter. plumbing tool, to cut the section of pipe out.
then used compression fitting. picked up a straight section of brake line.. 6 inches or so. and cut to needed length
6 bucks in parts.
leaks gone. but pedal is still smush and lights still on.

jjzepplin 02-23-2014 06:10 PM

Re: brake light staying on...
 
Sounds like you may have dodged a bullet. Now it is time to take advantage of your fortunate mishap and dodge some more that are surely on their way. Time to go through the whole system and find out what else is about to fail.

imjeff 02-23-2014 06:29 PM

Re: brake light staying on...
 
Quote:

Originally Posted by jasonroman (Post 6540540)
my guess is a wear hole. not sure why me slamming on brake to keep out of garage would blow it out??
i used a pipe cutter. plumbing tool, to cut the section of pipe out.
then used compression fitting. picked up a straight section of brake line.. 6 inches or so. and cut to needed length
6 bucks in parts.
leaks gone. but pedal is still smush and lights still on.

Don't guess with a hole in your brake line! That hard pedal hit would easily blow out a weak spot. The light is probably because of the sudden loss of fluid. It causes the switch to move and sometimes they don't reset easily. As said earlier, take this as an opportunity to overhaul your brake system. Sounds like you're plenty capable and it's cheap insurance.

Jeff

95 S_Trucker 02-23-2014 06:49 PM

Re: brake light staying on...
 
Please do yourself a favor and get that compression fitting off of your truck. I highly recommend using a flare nuts and inverted unions. If you don't feel comfortable doing it, take it to a shop and pay someone to do it.

You will need to get that bleeder out or replace the caliper if you want to bleed the brakes more.


If the master cylinder ran out of fluid, you may have to bench bleed it(can be done on the vehicle) and then bleed again at the wheel.

jasonroman 02-24-2014 08:53 AM

Re: brake light staying on...
 
thanks for replies guys
if money wasnt tight right now i would have already gotten all the parts for brakes front and rear. im just creaping by right now.
i did the flare thing on a c 10 i had. that when lowering the truck i cut threw line. but saw the compression fitting and thought it was easier then flaring lines.
right now im not interested in replacing all the lines in truck.
so i guess when i stompted on the brakes thats what blew the hole out.
this is a 3rd vehicle but i have been daily driving it instead of taking out my silverado. 94 with 5/7 drop. weve been slammed with snow lately.
i was gonna buy a newer tahoe before finding this old girl.
wanted a 4x4 for the winter. but as a c10 lover....i opted to go back to the oldies.

old Rusty C10 02-24-2014 10:08 AM

Re: brake light staying on...
 
when you replace the lines I like to go to advanced and get that copper colored coil and make/bend my own lines. Im still local , if you need to borrow some I have enough to do the whole back half of your truck

jjzepplin 02-24-2014 10:31 AM

Re: brake light staying on...
 
OK. So aside from replacing the lines that obviously should be replaced-(do that as soon as you can)- Your "brake" light is a switch in your proportioning valve (if you have disc front) and is probably triggered because your valve has been actuated. The prop valve is made to send all the fluid to the front or rear due to a failure such as yours. If you pull the wire from the valve your light should go out. This means your valve is triggered. (not the correct terms but you get it). DO NOT drive it this way! To fix usually you can open the other end Bleeders and stomp real hard on the pedal and it will correct itself. Mine was stuck for a long time this way and I had to take it apart to fix it. Shoved something small I think a drill bit backwards through it and re-centered the valve shaft. I moved it back and forth for a while to free it up and then set it in it's final resting place. Diagrams are available online. Then you must bleed carefully the whole system and pray you don't blow another line.

jasonroman 02-24-2014 01:08 PM

Re: brake light staying on...
 
so unplugging the wire will shut the light but not safe to drive without the wire plugged in?
bleeding the brakes will not be an option until i can afford to buy the calipers.brakes pads etc

LONGHAIR 02-24-2014 01:43 PM

Re: brake light staying on...
 
Unplugging that wire is just a test to show you that this is indeed the problem. The light can also be triggered by the emergency brake.
Do not drive it this way, especially in the snow. The system has "cut off" part of the braking to keep from pumping it dry. The only way to get it back is by equalizing the pressure. You are going to have to repair/replace the broken front bleeder anyway.

imjeff 02-24-2014 01:51 PM

Re: brake light staying on...
 
Bleeding the brakes and replacing that line are not expensive and do not require rebuild of the entire system. You are putting other people's lives at risk over a few bucks worth of brake fluid, bleeder and brake line. That is confounding.

jasonroman 02-24-2014 01:51 PM

Re: brake light staying on...
 
well i un plugged it and saw light go out. there is a plastic thing on top of the prop valve. not sure how to get it off. dont want to brake the plastic thing and give myself another problem. but under that cap thing, is that where i would stick something in?? like zeplin said earlier

jasonroman 02-24-2014 01:57 PM

Re: brake light staying on...
 
Quote:

Originally Posted by imjeff (Post 6541967)
Bleeding the brakes and replacing that line are not expensive and do not require rebuild of the entire system. You are putting other people's lives at risk over a few bucks worth of brake fluid, bleeder and brake line. That is confounding.

well as i said before. i sheared the bleeder off. not sure if thats fixable. my plan is not to injure anyone. plan is to fix when able.
not sure why using some brake line and compression fittings was such a bad idea. much easier then trying to bend lines to match. not to mention it was a small hole towards the end of one line.

will buy brake parts when i can afford it. as stated before.

donut 02-24-2014 07:33 PM

Re: brake light staying on...
 
Here's the deal. In Maine (just an example, I know your not there.), they did have safety inspections. Surface rust on a brake line =fail, cobbled patches=fail. (btw, that hole, was that the ONLY weak point?)

IIRC, brake fittings are supposed to be double flared. Compression fittings aren't rated anywhere near what your system can produce in a panic brake situation. Up there, we were required to replace the line at least back to the nearest factory fitting. Auto parts stores had the fittings and the lines, they were straight, but flared on both ends. They were also soft, so they could be bent by hand. Also various lengths ( I think 9" up to 4') Metric and standard.

All accidents weren't planned. Otherwise, they'd be on purposes ;)

I'm not busting on you, but what happens next time? (there will be a next time.)
Parts to repair it correctly are relatively cheap. Not counting a flaring tool, less than a tank of gas.

imjeff 02-24-2014 08:35 PM

Re: brake light staying on...
 
Quote:

Originally Posted by jasonroman (Post 6541977)
well as i said before. i sheared the bleeder off. not sure if thats fixable. my plan is not to injure anyone. plan is to fix when able.
not sure why using some brake line and compression fittings was such a bad idea. much easier then trying to bend lines to match. not to mention it was a small hole towards the end of one line.

will buy brake parts when i can afford it. as stated before.

The bleeder is a $1 part. If you can't get it out with an easy-out, a whole caliper is $30. Brake lines are way too cheap not to replace. Once you have that line and bleeder replaced you can bleed the brakes and your pedal will come back....with no light. That "small hole" may have just been the weakest link. Again, if you can't verify that brake line failed due to mechanical abrasion, you have to assume they are all in that shape. Brake fluid is very hygroscopic so it's not uncommon to have water in these old truck brake lines...and the resultant corrosion/rust problems. The compression fitting will not hold up. It will also put you in a bad situation should you have an accident. Please fix it correctly.

Jeff

jjzepplin 02-24-2014 09:28 PM

Re: brake light staying on...
 
Quote:

Originally Posted by jasonroman (Post 6541968)
well i un plugged it and saw light go out. there is a plastic thing on top of the prop valve. not sure how to get it off. dont want to brake the plastic thing and give myself another problem. but under that cap thing, is that where i would stick something in?? like zeplin said earlier

No that is not the place. That part is actually the electrical switch. If I remember right, I removed something from the front of the valve to gain access. This is advanced sort of stuff so I would go for that bleeder first. Replace that and bleed and you should be good till another hole appears or worse. As stated above-please consider lives of others as well as your own and do the right thing. Park it if you can't fix it right!

jasonroman 02-24-2014 10:14 PM

Re: brake light staying on...
 
I got the idea and appreciate concerns and replies. The truck will remain in the driveway. Il be running the silverado until I get the scratch to replace lines as well as brakes

cadillac_al 02-25-2014 10:22 AM

Re: brake light staying on...
 
I have never been able to remove a broken bleeder from a caliper so I always end up buying a new one. When you get a new one and are able to bleed the front brakes the proportion valve should center itself. In my experience it isn't uncommon to have a 6ft piece of brake line with 1 foot rusted out and the other 5 ft still shiny silver. I don't have a problem with replacing only the rusty part. If you don't have a flaring tool then sometimes it may be easier to replace the whole 6ft of line. In any event you should be able to get your truck going for less than $50.

jasonroman 02-25-2014 11:01 AM

Re: brake light staying on...
 
well if i was not in the red 6k. i would definutley have already purchased parts and stripped out the old for the new. aside from brake issues truck needs tune up and possible carb rebuild. so lucky for me i have the silverado to drive.


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