The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-16-2007, 10:59 PM   #1
grayw0lf
Registered User
 
Join Date: Apr 2004
Location: Clanton, AL
Posts: 1,253
Angry HELP! Brake light on! Pedal hard, tried everything.

Ok, so I recently put 6 lug disc brakes up front & I'm to the point where I want my drums back. Earlier I had a bad reman master cylinder, that problem is resolved. 71 style MC & used prop valve.

Now my Brake light comes on after I stop quick. The first time or 2, it goes off, then stays on. The pedal gets hard when the light comes on. Doing about 25mph downhill, I am unable to lockup any wheel. I've bled the brakes more than once.

Question1 - What gives? What am I doing wrong? Bad prop valve? (its the only thing not new).

Question2 - What does the brake light sensor signify? What exactly is it measuring?

I'm at my wit's end. Thanks for your response.

John
__________________
85' CUCV M1009!!! The newest addition!
6.2diesel, Th400, NP208, & only 36k miles!
70' C-10 LWB Fleetside - Looking good these days!
05' Dodge Neon
88' Winner Escape Sport 1750 - 4.3v6
94' Seadoo SP
84' Honda TRX200, bare nekkid. Just a frame & tires.

Always looking for another project or any good deal!

grayw0lf is offline   Reply With Quote
Old 08-16-2007, 11:14 PM   #2
Sammy
Registered User
 
Join Date: Apr 2000
Location: Bonne Terre, Mo
Posts: 3,005
Re: HELP! Brake light on! Pedal hard, tried everything.

Air... It will work it's way out eventially bleed it again. I think the brake light is telling you the valve is not centered to one side of the M/C. Did you bench bleed the new M/C using the small plastic tubes?
__________________
'69 Chevy Long Fleet & '71 GMC Short Step & Project "ODD BALL"


"You can wash a pig, soak it in most expensive perfume. In the end it is still just a pig."

ODD BALL build thread http://67-72chevytrucks.com/vboard/s...d.php?t=478629"
Sammy is offline   Reply With Quote
Old 08-16-2007, 11:34 PM   #3
grayw0lf
Registered User
 
Join Date: Apr 2004
Location: Clanton, AL
Posts: 1,253
Re: HELP! Brake light on! Pedal hard, tried everything.

Quote:
Originally Posted by Sammy View Post
Air... It will work it's way out eventially bleed it again. I think the brake light is telling you the valve is not centered to one side of the M/C. Did you bench bleed the new M/C using the small plastic tubes?
I did bench bleed using the little plastic plugs that came with it. I'll try & bench bleed it again tomorrow when I have a helper.

I know someone had mentioned in a diff thread to clamp the little button in the front of the prop valve when bleeding. The pin is already in. I can pull it out, but it seems spring loaded & restes "in" towards the main body of the prop valve.
__________________
85' CUCV M1009!!! The newest addition!
6.2diesel, Th400, NP208, & only 36k miles!
70' C-10 LWB Fleetside - Looking good these days!
05' Dodge Neon
88' Winner Escape Sport 1750 - 4.3v6
94' Seadoo SP
84' Honda TRX200, bare nekkid. Just a frame & tires.

Always looking for another project or any good deal!

grayw0lf is offline   Reply With Quote
Old 08-16-2007, 11:37 PM   #4
70c10
67-72 Addict!
 
70c10's Avatar
 
Join Date: Feb 2002
Location: The TAX State!
Posts: 7,856
Re: HELP! Brake light on! Pedal hard, tried everything.

I'll be watching this thread closely. I'm having the same hard peddle issue with my disc conversion. I'm pretty sure it's just air still in my lines.
__________________
Jim

1970 C/10 Fleetside w/Ghost Flames
Lowered 4.5" front and 4" rear (Raked)
355/350 Turbo w/shift kit
10" Redneck Performance Verter w/2500 stall
Hooker Super Comps part#2808-1
Performer RPM Air-Gap
12 Bolt w/3:73 gears- Eaton Posi
Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads
70c10 is offline   Reply With Quote
Old 08-16-2007, 11:45 PM   #5
jhow66
Registered User
 
jhow66's Avatar
 
Join Date: Jun 2002
Location: Knoxville Tenn.
Posts: 3,058
Re: HELP! Brake light on! Pedal hard, tried everything.

This should help:
http://www.classicperform.com/TechBo...t.htm#testprop
__________________
56 Chevy Bel-Air 2dr. HT (purchased new)
71 Chevy Cheyenne SWB PU (502HO)
65 GMC short bed step--work in progress and my gofer
jhow66 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:38 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com