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tclark
Samba Member
Joined: November 21, 2005
Posts: 926
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 Posted: Wed Feb 03, 2010 5:10 pm Post subject: Cherry Red Hot Rotors but calipers release? |
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OK I am kinda stumped here
Usual week-end up in the ski hills coming back down I smell
burning brakes not so unusual since its 100's of cars with the brakes light on ..
so I gotta do like wise ...
but as we level out its getting kinda intense so I pull over to have a peak
well the driver side looks ok not too bad a smell BUT
passenger side right rotor is like a nice cherry red sun set..
beautiful 
nothing to do here its cold out we hit the hwy & checking in 30 mins & its cooled down and the brakes work but feel kinda spongy but are ok ..
I think prolly boiled the fluid & thats gonna leave some gas bubble as it cools down...
and I am thinking a seized caliper was the root cause ...
So today I get a helper get the right up in the air & we play the you pump the brakes & I check the caliper...
well hes on the brake the wheel is locked up he releases & the wheel spins just fine & I can kinda see the pad back off as he release's ...
and the pad dont event look torched maybe a bit glazed
ok WTF is going on here ??
1) I am not getting even hydraulics pressure on the driver side ???
ok after the help vanished I went out & ran it up to 50 ish took
my hand off the wheel & nailed the brakes thier is a light pull to the
right side but cant be sure that was not caused by road camber but definitely pull right
so maybe un-even hydraulics pressure what can cause this ??
2) this is normal if you descend to much & your in a line of modern vehicles
with the brakes on & you drive vanagon with std under sized brakes this is to be expected 
oh and any you Van Isers you guessed it yup coming down in that hell convoy from http://mountwashington.ca
_________________
89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold)
Last edited by tclark on Wed Feb 03, 2010 8:17 pm; edited 1 time in total |
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buildyourown
Samba Member
Joined: March 01, 2009
Posts: 1668
Location: Seattle
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| Posted: Wed Feb 03, 2010 6:41 pm Post subject: |
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Were both sides red?
That will answer your question regarding sticky caliper vs undeven pressure vs normal heat.
Side to side disparity in pressure seems unlikely as (IIRC) both fronts are on the same circuit. A clogged line maybe, but not something I've ever seen.
Do the brakes feel good now? You may have cooked the pads/fluid beyond recovery. If the feel decent, I'd just drive it and pay attention. |
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?Waldo?
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Joined: February 22, 2006
Posts: 9752
Location: Where?
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| Posted: Wed Feb 03, 2010 6:47 pm Post subject: |
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| buildyourown wrote: |
| A clogged line maybe, but not something I've ever seen. |
I have seen a semi-clogged line that caused pulling to the right when braking. It took a heck of a lot to figure out too, as I did a two person bleeding each time and someone else was pushing the pedal. It passed fluid so it all seemed fine on my end. There was eventually that one errant comment (after doing an inordinate amount of unnecessary work) that the pedal pusher made, "Oh, that feels better, it's a bit more firm," and my response, "What?! I have the bleeder fully open..." |
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82WestyMan
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Joined: December 28, 2006
Posts: 1098
Location: Western OR
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| Posted: Wed Feb 03, 2010 7:21 pm Post subject: |
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If I had to venture a guess from your symptoms, I'd say brake hose
The cherry red rotor definately says that brake isn't releasing
But to come back later to find the caliper is released sounds like a classic symptom of a brake hose with interior deterioration.
It's allowing the pressure to build up to apply the brake but isn't quickly releasing that pressure when you let up on the pedal
Does sound like you boiled the fluid though.
I'd replace both from brake hoses (all four if you're not sure of their age) and totally flush the system with fresh fluid
_________________
"The floggings will continue until morale improves"
"I never did give anybody hell. I just told the truth and they thought it was hell" - Harry S. Truman
82 Westfalia - w/ a Raby 'Camper Special' engine |
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thummmper
Samba Member
Joined: November 25, 2009
Posts: 2015
Location: Meadow Valley, California Republic
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| Posted: Wed Feb 03, 2010 11:07 pm Post subject: |
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| take your calipers off and grease the slides. scrounge some accelerator cable boots from the bone yard and replace any on your little slide shafts that are shredded. this will keep the grease in and the dust+ out. I removed those slider bolts/shafts and cleaned them up on my wire wheel. they were rusty and stuck. thats the problem 90% of the time. your pads will wear unevenly and behave badly. todd |
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randywebb
Samba Member
Joined: February 15, 2005
Posts: 3815
Location: Greater Metropolitan Nimrod, Orygun
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| Posted: Thu Feb 04, 2010 12:10 am Post subject: |
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How old are your rubber brake hoses?
How old is the brake fluid? |
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tclark
Samba Member
Joined: November 21, 2005
Posts: 926
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| Posted: Thu Feb 04, 2010 11:56 am Post subject: |
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yah lines , fluid, caliper, pad are 2.5 year old & the rear are a few week older
but the master is ancient I have spare under the rear seat
I am going with the un-even pressure theory lube the caliper slides, then I am gonna drain the fluid out a few times, waste a few pints & see what muck comes out
if the they are still spongy after that and the bleed
then I am gonna pt the finger at master some how not delivering even pressure to all lines .. (grasping at straws)
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89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold) |
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j_dirge
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Joined: August 08, 2007
Posts: 4641
Location: Twain Harte, CA
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| Posted: Thu Feb 04, 2010 12:24 pm Post subject: |
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I cooked my brakes coming down a steep section of Sonora Pass a while back and they've never felt right since. (if OE Vanagon brakes coulde EVER feel "right")
Doubt its my master cylinder as I replaced it, new just prior.
Trying to maintain speed in the flow of traffic with modern cars is what could have got me killed.
Someohow I grew complacent thinking the Vanagon could stop any better than my old Baywindow...
Never again.. going to big Audi brakes up front.
In the meantime, I'm doing what was suggested back up the thread a ways..
Replaced the fluid which, no doubt, cooked.
And just paying attention to them until the fronts are replaced entirely and the rears get a complete rebuild, including new drums, lines, etc.
Let us know how it works out.
_________________
-89 GL Westy, SVX.. finally.
-57 pan f/g buggy with a 67 pancake Type 3 "S"
"Jimi Hendrix owned one. Richard Nixon did not"
-Grand Tour, Season 1, episodes 4 and 5
| danfromsyr wrote: |
those are straight line runs with light weight race cars for only 1/4mile at a time..
not pushing a loaded brick up a mountain pass with a family of 4+ inside expecting to have an event free vacation..
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madspaniard
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Joined: August 18, 2008
Posts: 3795
Location: Alameda, CA
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| Posted: Thu Feb 04, 2010 12:37 pm Post subject: |
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| Andrew A. Libby wrote: |
| buildyourown wrote: |
| A clogged line maybe, but not something I've ever seen. |
I have seen a semi-clogged line that caused pulling to the right when braking. It took a heck of a lot to figure out too, as I did a two person bleeding each time and someone else was pushing the pedal. It passed fluid so it all seemed fine on my end. There was eventually that one errant comment (after doing an inordinate amount of unnecessary work) that the pedal pusher made, "Oh, that feels better, it's a bit more firm," and my response, "What?! I have the bleeder fully open..." |
Ok, I'm having this same problem pulling to the right when braking and after checkng a few things I think you just solved the problem for me so thank you!
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1991 Westy auto w/ Peloquin TBD
"The only difference between me and a madman is that I'm not mad” - Salvador Dali |
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randywebb
Samba Member
Joined: February 15, 2005
Posts: 3815
Location: Greater Metropolitan Nimrod, Orygun
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| Posted: Thu Feb 04, 2010 6:13 pm Post subject: |
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| you should flush the fluid every 2 years max. - 2.5 yrs is too old, but that is unlikely to be this problem |
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?Waldo?
Samba Member
Joined: February 22, 2006
Posts: 9752
Location: Where?
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| Posted: Thu Feb 04, 2010 6:30 pm Post subject: |
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| madspaniard wrote: |
| Andrew A. Libby wrote: |
| buildyourown wrote: |
| A clogged line maybe, but not something I've ever seen. |
I have seen a semi-clogged line that caused pulling to the right when braking. It took a heck of a lot to figure out too, as I did a two person bleeding each time and someone else was pushing the pedal. It passed fluid so it all seemed fine on my end. There was eventually that one errant comment (after doing an inordinate amount of unnecessary work) that the pedal pusher made, "Oh, that feels better, it's a bit more firm," and my response, "What?! I have the bleeder fully open..." |
Ok, I'm having this same problem pulling to the right when braking and after checkng a few things I think you just solved the problem for me so thank you! |
If there is more resistance to the pedal with the left bleeder open than with the right or vice versa, then there is a restriction in the line somewhere. |
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tclark
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Joined: November 21, 2005
Posts: 926
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| Posted: Fri Feb 19, 2010 9:18 am Post subject: |
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well just for the archives
I RnR the master cylinder went for a drive up the big mountain & back down
CherryRed again
So thought it was time to inspect all 4 corners
the issue here was that the right rear drum shoe were worn almost to metal but the left rear had normal wear ??
I assumed the something sticking so just did a full RnR (cylinders, shoes, etc) on the right rear now all is good again ...
Theory on why its was front right that was cherry red ...
w/o any right rear braking the right front was doing more than is share of the work, maybe even uneven pressure to that side ...
_________________
89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold) |
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