1969 brake pedal won't fully return, brake lights staying on, somewhat soft feel
07-11-2019, 09:20 PM
#1
Racer
Thread Starter
1969 brake pedal won't fully return, brake lights staying on, somewhat soft feel
Hello everyone.
I've read until my eyes bleed, but I can't really find what I need in the search here or on google.
I just picked up my '69 from the local service shop following a front end alignment after having installed the Borgeson power steering upgrade a week ago.
The shop guy says "Hey, has your battery been running dead on you lately?" I say "no, why"? "Well, your brake lights aren't turning off."
This was not happening before I dropped it off. I stare at my car every night (admiring the curves) and I would have noticed the tail lights staying on.
We checked and the brake pedal was not fully returning, being just about 1/4" from fully out position. Initially, I thought it was a loose switch, which was part of the problem. I readjusted that so that now, with the pedal in the fully out position, the lights are disengaged.
However, the pedal will not return to the fully out position after having been pressed in. It 'catches' just 1/4" shy and requires that I use my foot to pull it out that last 1/4". It stays in this fully out position until I push in again to brake, but then sticks again on the way out. It requires very little effort to pull it out that last little bit. I've read that this could be a possible booster problem or master cylinder problem. I've read that its normal to have a little bit of play in the brake pedal before engagement, but this 'sticking' doesn't seem normal and is what's causing the brake lights to stay on.
I've checked the master cylinder for leaks, none, fluid reservoir is full, seal seem good. I've removed it from the booster and checked the 'rod' that goes into the booster and that moves freely. I push it all the way it will go in and when I push on the brake pedal, it comes out. Brakes have felt a little soft since I've owned it, but have always worked well. Brakes calipers and pads were checked a few months ago and all looked good. No leaks at the calipers.
How else can I diagnose if its the cylinder or the booster? Could it be something else? I'm not a mechanic, but I'm learning as I go.
Thanks in advance for any help!
Sean
I've read until my eyes bleed, but I can't really find what I need in the search here or on google.
I just picked up my '69 from the local service shop following a front end alignment after having installed the Borgeson power steering upgrade a week ago.
The shop guy says "Hey, has your battery been running dead on you lately?" I say "no, why"? "Well, your brake lights aren't turning off."
This was not happening before I dropped it off. I stare at my car every night (admiring the curves) and I would have noticed the tail lights staying on.
We checked and the brake pedal was not fully returning, being just about 1/4" from fully out position. Initially, I thought it was a loose switch, which was part of the problem. I readjusted that so that now, with the pedal in the fully out position, the lights are disengaged.
However, the pedal will not return to the fully out position after having been pressed in. It 'catches' just 1/4" shy and requires that I use my foot to pull it out that last 1/4". It stays in this fully out position until I push in again to brake, but then sticks again on the way out. It requires very little effort to pull it out that last little bit. I've read that this could be a possible booster problem or master cylinder problem. I've read that its normal to have a little bit of play in the brake pedal before engagement, but this 'sticking' doesn't seem normal and is what's causing the brake lights to stay on.
I've checked the master cylinder for leaks, none, fluid reservoir is full, seal seem good. I've removed it from the booster and checked the 'rod' that goes into the booster and that moves freely. I push it all the way it will go in and when I push on the brake pedal, it comes out. Brakes have felt a little soft since I've owned it, but have always worked well. Brakes calipers and pads were checked a few months ago and all looked good. No leaks at the calipers.
How else can I diagnose if its the cylinder or the booster? Could it be something else? I'm not a mechanic, but I'm learning as I go.
Thanks in advance for any help!
Sean
07-12-2019, 02:15 AM
#2
Melting Slicks
Member Since: Jul 2010
Location: perth western australia
Posts: 3,099
Received 599 Likes
on
533 Posts
There should be a coil spring up on the pedals pivot arm that helps the return. If it's original.its usually less strong as new , maybe it's just recently broken ???.
07-12-2019, 05:37 AM
#3
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,442
Received 6,291 Likes
on
3,919 Posts
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I had the exact same problem on my 68. Its the power booster. I just replace mine and the brake pedals stays up top, quick to return, and very firm now.(sounds like a blue pill commercial). I did a bunch of research before hand and I finally found the answer
Now I have glazed brakes and air in my lines to deal with from a track day event.
Now I have glazed brakes and air in my lines to deal with from a track day event.
Last edited by Rescue Rogers; 07-12-2019 at 05:39 AM.
07-12-2019, 09:42 AM
#5
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,442
Received 6,291 Likes
on
3,919 Posts
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Not to hijack the thread, but repeated 50-70 mph runs and hitting the brakes to the point of skidding then rolling thru to full throttle again after the apex, 11 times a lap, really takes a toll on them.....but it is the most fun you can have, legally, in these things!!! The course is behind the logo and I could hit 70mph easily on the back straight as well as the front. I think I have a video on the "scream of silence thread"
https://www.corvetteforum.com/forums...rfunkel-2.html
Last edited by Rescue Rogers; 07-13-2019 at 06:46 AM.
07-12-2019, 11:07 AM
#6
Racer
Thread Starter
Thanks for the replies. Should I have the current booster rebuilt or buy a new one? I've read that there may be some modifications needed for fitment with some new boosters and I'm not ready to tackle that. However, I would assume that newer boosters would be better? At least I would be assured that this current booster rebuilt would fit back in place without issue.
Any need to replace the master cylinder at the same time? As I said before, it appears to be fine, no leaks anyway. I did notice last night that the fluid level was at the brim and actually seeping over when I removed the cap, so I removed a bit to where the level is now about 3/8" lower than the top.
Any need to replace the master cylinder at the same time? As I said before, it appears to be fine, no leaks anyway. I did notice last night that the fluid level was at the brim and actually seeping over when I removed the cap, so I removed a bit to where the level is now about 3/8" lower than the top.
Last edited by SonOfGaladriel; 07-12-2019 at 11:08 AM.
07-12-2019, 11:22 AM
#7
Racer
Not to hijack the thread, but repeated 50-70 mph runs and hitting the brakes to the point of skidding then rolling thru to full throttle again after the apex, 11 times a lap, really takes a toll on them.....but it is the most fun you can have, legally, in these things!!! The course is behind the log and I could hit 70mph easily on the back straight as well as the front. I think I have a video on the "scream of silence thread"
https://www.corvetteforum.com/forums...rfunkel-2.html
The following users liked this post:
Rescue Rogers (07-13-2019)
07-12-2019, 11:46 AM
#8
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,442
Received 6,291 Likes
on
3,919 Posts
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Thanks for the replies. Should I have the current booster rebuilt or buy a new one? I've read that there may be some modifications needed for fitment with some new boosters and I'm not ready to tackle that. However, I would assume that newer boosters would be better? At least I would be assured that this current booster rebuilt would fit back in place without issue.
Any need to replace the master cylinder at the same time? As I said before, it appears to be fine, no leaks anyway. I did notice last night that the fluid level was at the brim and actually seeping over when I removed the cap, so I removed a bit to where the level is now about 3/8" lower than the top.
Any need to replace the master cylinder at the same time? As I said before, it appears to be fine, no leaks anyway. I did notice last night that the fluid level was at the brim and actually seeping over when I removed the cap, so I removed a bit to where the level is now about 3/8" lower than the top.
07-12-2019, 12:10 PM
#9
Racer
Thread Starter
Thank you Rescue. I've just looked at RockAuto and they have an ACDelco remanufactured unit for half the price of Summit. How can that be?
Also, I've just performed the brake booster 'test'. With car off, pumped brakes 6 times, left gentle pressure on the brake, started car, brake pedal lowered about 1/4 to 1/2 inch and remained there with gentle pressure. Apparently, this means my booster is functioning correctly.
Another detail on the brake pedal: Does it mean anything if when I pull up that last 1/4" or so it kind of 'clicks' as if its reached a somewhat soft stopping point and needs just a little more 'oomph' to get it past that sticking point? Meaning, its not a soft smooth transition from that stopping point to fully out position. Does that make any sense?
Also, I've just performed the brake booster 'test'. With car off, pumped brakes 6 times, left gentle pressure on the brake, started car, brake pedal lowered about 1/4 to 1/2 inch and remained there with gentle pressure. Apparently, this means my booster is functioning correctly.
Another detail on the brake pedal: Does it mean anything if when I pull up that last 1/4" or so it kind of 'clicks' as if its reached a somewhat soft stopping point and needs just a little more 'oomph' to get it past that sticking point? Meaning, its not a soft smooth transition from that stopping point to fully out position. Does that make any sense?
07-12-2019, 01:21 PM
#10
Racer
Thread Starter
The brake pedal is definitely getting stuck in the position just when you start to feel the brake pressure when applying. Upon letting off, it sticks there and won't return high enough to engage the switch without me manually lifting it back up. There is an audible click and slight jump of the brake pedal when pulling it back to fully out position.
Again, I cant find anything wrong with the master cylinder. It holds pressure during a prolonged push at full brake. There are no air bubbles during slow brake pedal movements and it squirts when brakes are applied hard. As above, booster seems to check out. Unless there is something wrong with the rod that attaches to the brake pedal. That seems to be the most likely area.
Any more thoughts? Just trying to accurately diagnose this problem before ordering parts I may not actually need.
Thanks for your patience with me.
Again, I cant find anything wrong with the master cylinder. It holds pressure during a prolonged push at full brake. There are no air bubbles during slow brake pedal movements and it squirts when brakes are applied hard. As above, booster seems to check out. Unless there is something wrong with the rod that attaches to the brake pedal. That seems to be the most likely area.
Any more thoughts? Just trying to accurately diagnose this problem before ordering parts I may not actually need.
Thanks for your patience with me.
Last edited by SonOfGaladriel; 07-12-2019 at 01:23 PM.
07-12-2019, 03:41 PM
#11
Safety Car
You said that when you manually lift up on the brake pedal you hear a click. Is it possible the switch is binding internally and holding the pedal the last 1/4 inch then working (shutting off) when you lift up on the pedal? Check the switch plunger itself for ease of movement.
Last edited by CanadaGrant; 07-12-2019 at 03:45 PM.
07-12-2019, 04:20 PM
#12
Racer
Thread Starter
You said that when you manually lift up on the brake pedal you hear a click. Is it possible the switch is binding internally and holding the pedal the last 1/4 inch then working (shutting off) when you lift up on the pedal? Check the switch plunger itself for ease of movement.
I spent the last 90 minutes down under there again this afternoon. Not a very comfortable position to say the least and I can only use my left hand to get up in there with the wrench (I'm not left handed!).
I started wondering if maybe I was expecting the brake pedal to come out further than its supposed to and further out than it has been the entire time I've owned it. As it sits in the 'stuck' position, its about even with the gas pedal, about 5 1/2" away from the fire wall measured at the top of the pedal. When I pull it out to its furthest position, it sits about 1/2" above the gas pedal (6" away from the fire wall). I was able to realign the activation plate that is attached to the brake lever that makes contact with the switch so that it now engages in this 'stuck' position and now the brake lights go off! No longer a need to manually pull up on the brake pedal that last little bit to disengage the brake lights! I took it for a spin and brakes work fine.
I think I'll go with this fix for now and look into possibly a new booster a bit down the road to see if the firms up the brakes a bit more. I'm still paying off the Borgeson install and front end alignment as well as rear wheel bearings and new pads and rotors on my '09 CTS! Its been an expensive summer on the old cars.
07-12-2019, 06:41 PM
#13
Racer
07-12-2019, 09:39 PM
#15
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,442
Received 6,291 Likes
on
3,919 Posts
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
From what I have read there is a spring internal to the booster that can fail and that can be the issue, (not sure if there is). I have also read that the internal vent that allows air back into the booster to allow the pedal to return to its full height can fail, so when it tries to return it is pulling against the vacuum internal to the booster, (most likely). My booster passed all those tests as well. It wasnt expensive, I figured I would try it and I could return it if it wasnt the issue. It was and now its fixed. I know its weird but the other site i got this info off of was having this same conversation.
They talked air in lines, bad masters, bad distribution block, sticking calipers and collapsed lines...One guy kept saying it was the booster.
I had a spring that I added to the pedal up to the steering column bracket on the dash to get it to return that last 1/4 inch last fall and this spring. I hated it and it took me forever to find that other thread. Trust me, I would be surprised if it wasnt the issue.
They talked air in lines, bad masters, bad distribution block, sticking calipers and collapsed lines...One guy kept saying it was the booster.
I had a spring that I added to the pedal up to the steering column bracket on the dash to get it to return that last 1/4 inch last fall and this spring. I hated it and it took me forever to find that other thread. Trust me, I would be surprised if it wasnt the issue.
Last edited by Rescue Rogers; 07-12-2019 at 09:41 PM.
07-12-2019, 10:38 PM
#16
Le Mans Master
Not to hijack the thread, but repeated 50-70 mph runs and hitting the brakes to the point of skidding then rolling thru to full throttle again after the apex, 11 times a lap, really takes a toll on them.....but it is the most fun you can have, legally, in these things!!! The course is behind the log and I could hit 70mph easily on the back straight as well as the front. I think I have a video on the "scream of silence thread"
https://www.corvetteforum.com/forums...rfunkel-2.html
The following users liked this post:
Rescue Rogers (07-13-2019)