I suspect a brake proportioning valve turns the dash light on when the brake pressures are out of balance.
http://www.classicperform.com/Instructions/PDF/PVK.pdf > -----Original Message----- > From: Mercedes [mailto:mercedes-boun...@okiebenz.com] On Behalf Of > Kaleb C. Striplin via Mercedes > Sent: Friday, May 24, 2019 10:36 PM > To: mercedes@okiebenz.com > Cc: Kaleb C. Striplin <ka...@striplin.net> > Subject: Re: [MBZ] Chebby brakes > > Must be the back since they are not properly adjusted yet. > > What I am trying to figure out is what the deal is the brake warning light in > the > cluster. It comes on when the parking brake is set. Also, when I was pushing > the pedal the other day it was off, but would come on as the pedal got close > to > the floor. Today it seems to stay on all the time. As far as I can tell, > there is no > electrical connection at the MC. Supposedly the light indicates if the > parking > brake is on or if there is a braking issue. I wonder if there is some switch > somewhere in the system that if the pedal goes too far to the floor it turns > the > light on. I can't seem to find much info on exactly what is tied into that > light. > > On 5/24/2019 9:27 PM, Scott Ritchey via Mercedes wrote: > > Remember that the MC has two sections (front and back brakes). Sounds > like one of them isn't working. > > > >> -----Original Message----- > >> From: Mercedes [mailto:mercedes-boun...@okiebenz.com] On Behalf Of > >> Kaleb Striplin via Mercedes > >> Sent: Friday, May 24, 2019 4:42 PM > >> To: Mercedes Discussion List <mercedes@okiebenz.com> > >> Cc: Kaleb Striplin <ka...@striplin.net> > >> Subject: Re: [MBZ] Chebby brakes > >> > >> The braking effort seems fine. This has the hydro boost brakes rather > >> than the vacuum booster. I’m still suspecting the MC is weak. It’s > >> not expensive or hard to replace so I will probably replace it. > >> > >> Sent from my iPhone > >> > >>> On May 24, 2019, at 3:06 PM, G Mann via Mercedes > >> <mercedes@okiebenz.com> wrote: > >>> I'm glad you mentioned that leading wheel cylinder issue. > >>> Which leads me to this: > >>> If the brake fluid is rank, which it was, and the wheel cylinder is > >>> leaking, it's likely the master cylinder rubber cups are also > >>> leaking, just a bit. When master cylinder leaks on Chebbys with > >>> brake vacuum booster behind it, the brake fluid eats the diaphragm > >>> in the vac brake booster, which means, you do not get "full brake > >>> assist" from the brake > >> booster. > >>> Eventually, the leak will get so bad you can hear vacuum leak > >>> sucking when you press the brakes, which are not doing their job. > >>> > >>> Could you have a failed or failing vac brake booster? If you do, > >>> ALWAYS replace booster and master cylinder as a pair. > >>> It's a Chebby falt point. might just be why brakes have been crap > >>> and still are. > >>> > >>> On Fri, May 24, 2019 at 12:55 PM Kaleb Striplin via Mercedes < > >>> mercedes@okiebenz.com> wrote: > >>> > >>>> The rear wheel cylinders were leaking and contaminated the shoes so > >>>> that is why o replaced all that. I’m going to adjust the shoes > >>>> either today or tomorrow then see what happens. It’s either that or > >>>> I somehow still have air on the lines, which I can’t see how. Or > >>>> air on master cylinder or it’s bad, it if it was bad I would think > >>>> it would start > >> sinking to the floor. > >>>> > >>>> > >>>> Sent from my iPhone > >>>> > >>>>> On May 24, 2019, at 2:41 PM, G Mann via Mercedes > >>>>> <mercedes@okiebenz.com> > >>>> wrote: > >>>>> In the interest of time and effort, try adjusting them, wheels on. > >>>>> If > >>>> they > >>>>> don't adjust out enough to lock up the wheel, then it's time to > >>>>> pull the drums and take them to FLAPS to be measured for ID. Could > >>>>> be why you > >>>> never > >>>>> had good brakes to start with, some dip wit did a brake job and > >>>>> took the drums beyond limit, so even though they "look fresh" they > >>>>> should, since > >>>> the > >>>>> shoes weren't rubbing on them, ha. > >>>>> > >>>>> That truck should be able to lock up the wheels when you stomp the > >>>>> brake, so something is not where it should be. > >>>>> > >>>>> On Fri, May 24, 2019 at 12:26 PM Kaleb Striplin via Mercedes < > >>>>> mercedes@okiebenz.com> wrote: > >>>>> > >>>>>> I will probably pull the wheels back off and adjust the shoes, or > >>>>>> I > >>>> guess > >>>>>> I could do it with the wheels on. I did not measure the drums, > >>>>>> they > >>>> still > >>>>>> looked good with very little wear, at least they did not have a > >>>>>> ridge at the edge. I hate drum brakes. > >>>>>> > >>>>>> Sent from my iPhone > >>>>>> > >>>>>>> On May 24, 2019, at 2:19 PM, G Mann via Mercedes < > >>>> mercedes@okiebenz.com> > >>>>>> wrote: > >>>>>>> If you want bad brakes, rely on the automatic adjusters. > >>>>>>> If you want good full pedal, adjust the shoes till they lock up > >>>>>>> the > >>>>>> wheel, > >>>>>>> then back the adjuster off until you just can feel a very light drag. > >>>>>> First > >>>>>>> couple of hard stops will "wear in" the shoes and you will turn > >>>>>>> free > >>>> with > >>>>>>> no drag. > >>>>>>> OR, > >>>>>>> Find a clear area and back up, hit the brakes while backing up, > >>>> multiple > >>>>>>> times ie pump, pump, pump.. pull forward and do it again and again. > >>>>>>> The only time automatic adjusters engage is when you are backing > >>>>>>> up, [clever huh?] My personal preference is to manually adjust > >>>>>>> them so I can actually > >>>> feel > >>>>>>> that I have full contact, then back the adj off a touch. > >>>>>>> > >>>>>>> You will much improve pedal travel and brake contact. > >>>>>>> > >>>>>>> Question: Did you measure the rear drums when you had them off? > >>>>>>> It's possible they were turned to the limit at last brake job > >>>>>>> and are now > >>>> out > >>>>>> of > >>>>>>> limit large, so even new shoes won't fill the space? > >>>>>>> > >>>>>>> On Fri, May 24, 2019 at 11:53 AM Kaleb C. Striplin via Mercedes > >>>>>>> < mercedes@okiebenz.com> wrote: > >>>>>>> > >>>>>>>> If the master cylinder has air in it, will bleeding at the > >>>>>>>> wheels > >>>> remove > >>>>>>>> that air, or does it need to be bled in a separate procedure? > >>>>>>>> > >>>>>>>>> On 5/24/2019 1:21 PM, Kaleb C. Striplin via Mercedes wrote: > >>>>>>>>> Yea I guess I could try that. I had planned on just letting > >>>>>>>>> them adjust out on their own. > >>>>>>>>> > >>>>>>>>>> On 5/24/2019 1:18 PM, Meade Dillon via Mercedes wrote: > >>>>>>>>>> So have you adjusted out the rear brake drums? If not, that > >>>>>>>>>> would > >>>> be > >>>>>> my > >>>>>>>>>> next move. > >>>>>>>>>> ------------- > >>>>>>>>>> Max > >>>>>>>>>> Charleston SC > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> On Fri, May 24, 2019 at 2:15 PM Kaleb C. Striplin via > >>>>>>>>>> Mercedes < mercedes@okiebenz.com> wrote: > >>>>>>>>>> > >>>>>>>>>>> Ok, I a bled the crap out of it. I did the bleeder at the > >>>>>>>>>>> abs > >>>> unit, > >>>>>>>>>>> then did all the wheels again started and RR, the LR, RF, LF. > >>>>>>>>>>> I ran about 3qts of fluid thru it. At all wheels I have > >>>>>>>>>>> clean fluid and > >>>> no > >>>>>>>>>>> bubbles coming out. Took it out and it still has very > >>>>>>>>>>> little > >>>>>> braking. > >>>>>>>>>>> Pedal goes probably 3/4 of the way to the floor till any > >>>>>>>>>>> sort of braking action happens. It will stop, but not very > >>>>>>>>>>> fast and would not stop pulling a trailer. Even if the back > >>>>>>>>>>> brakes were not fully adjusted > >>>>>> out > >>>>>>>>>>> yet it would be better than this. When I pump the pedal it > >>>>>>>>>>> does > >>>>>> return > >>>>>>>>>>> but its not an instant return as soon as you left off the pedal. > >>>>>> Also, > >>>>>>>>>>> when just holding steady pressure at about the half pedal > >>>>>>>>>>> travel or oven > >>>>>>>>>>> 3/4 travel pedal does not sink it seems to stay steady. > >>>>>>>>>>> Also, the > >>>>>> red > >>>>>>>>>>> brake lite is on that would come on if the parking brake is > >>>>>>>>>>> on, the manual says this indicates a brake problem. No joke. > >>>>>>>>>>> I really do > >>>>>> not > >>>>>>>>>>> see how I could still have air in the lines. Brakes are > >>>>>>>>>>> worse than they were before I replaced the rear wheel > >>>>>>>>>>> cylinders but they were never very good in the first place. > >>>>>>>>>>> The front calipers and hoses are fairly new also. > >>>>>>>>>>> > >>>>>>>>>>> > >>>>>>>>>>> > >>>>>>>>>> _______________________________________ > >>>>>>>>>> http://www.okiebenz.com > >>>>>>>>>> > >>>>>>>>>> To search list archives http://www.okiebenz.com/archive/ > >>>>>>>>>> > >>>>>>>>>> To Unsubscribe or change delivery options go to: > >>>>>>>>>> > >> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>>>>>>>> --- > >>>>>>>>> This email has been checked for viruses by AVG. > >>>>>>>>> https://www.avg.com > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> _______________________________________ > >>>>>>>>> http://www.okiebenz.com > >>>>>>>>> > >>>>>>>>> To search list archives http://www.okiebenz.com/archive/ > >>>>>>>>> > >>>>>>>>> To Unsubscribe or change delivery options go to: > >>>>>>>>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.co > >>>>>>>>> m > >>>>>>>>> > >>>>>>>> _______________________________________ > >>>>>>>> http://www.okiebenz.com > >>>>>>>> > >>>>>>>> To search list archives http://www.okiebenz.com/archive/ > >>>>>>>> > >>>>>>>> To Unsubscribe or change delivery options go to: > >>>>>>>> > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>>>>>>> > >>>>>>>> > >>>>>>> _______________________________________ > >>>>>>> http://www.okiebenz.com > >>>>>>> > >>>>>>> To search list archives http://www.okiebenz.com/archive/ > >>>>>>> > >>>>>>> To Unsubscribe or change delivery options go to: > >>>>>>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>>>>>> > >>>>>> > >>>>>> _______________________________________ > >>>>>> http://www.okiebenz.com > >>>>>> > >>>>>> To search list archives http://www.okiebenz.com/archive/ > >>>>>> > >>>>>> To Unsubscribe or change delivery options go to: > >>>>>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>>>>> > >>>>>> > >>>>> _______________________________________ > >>>>> http://www.okiebenz.com > >>>>> > >>>>> To search list archives http://www.okiebenz.com/archive/ > >>>>> > >>>>> To Unsubscribe or change delivery options go to: > >>>>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>>>> > >>>> > >>>> _______________________________________ > >>>> http://www.okiebenz.com > >>>> > >>>> To search list archives http://www.okiebenz.com/archive/ > >>>> > >>>> To Unsubscribe or change delivery options go to: > >>>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>>> > >>>> > >>> _______________________________________ > >>> http://www.okiebenz.com > >>> > >>> To search list archives http://www.okiebenz.com/archive/ > >>> > >>> To Unsubscribe or change delivery options go to: > >>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > >>> > >> > >> _______________________________________ > >> http://www.okiebenz.com > >> > >> To search list archives http://www.okiebenz.com/archive/ > >> > >> To Unsubscribe or change delivery options go to: > >> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > > _______________________________________ > > http://www.okiebenz.com > > > > To search list archives http://www.okiebenz.com/archive/ > > > > To Unsubscribe or change delivery options go to: > > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
