Date: Sun, 26 May 2013 13:43:51 -0700
Reply-To: Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject: Re: Causes of Brake Pull at Highway Speeds? UPDATE
In-Reply-To: <CAB2RwfjFZGNifL3Lz+TVL_MWjfgrvLW0ZtfAiM38QxAzYAX38A@mail.gmail.com>
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I've seen brake hoses swell on the inside and act as a one way valve. Your
problem sounds like a bad caliper though. Heat is causing it to tighten and
possibly bind in the bore. As you lighten up on the pedal the good one
releases and the bad one doesn't.
Replace them both along with the hoses if you haven't done that already.
Good luck!
Stuart
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
neil n
Sent: Sunday, May 26, 2013 11:22 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Causes of Brake Pull at Highway Speeds? UPDATE
So another shop checked out my '81. The owner took a pry bar to the
front end, did a visual inspection and found no issues (excessive play
etc.). We don't think my radius arm hole repair is the issue. He
thinks a faulty rebuilt caliper may be causing the pull. He has found
that with some rebuilt calipers, the piston O ring (seal) may cause
the piston not to move properly. I have far less experience than him
so don't see how this would cause a pull while braking HARD at ~ 50
MPH + but......
How would a caliper piston O ring cause this? Like even if braking
hard, can the O ring hold the piston firmly enough that (in my case)
it won't allow the driver side pads to move as well (push as hard on
the rotor) as the pass. side pads?
A side note. He adjusted the brake shoes and noted that the e-brake
was adjusted as far as it can go. I may have worded my question to him
poorly, but I asked if backing off the e-brake adjustment would allow
more adjustment at the shoes and allow the e-brake to be adjusted
properly. He said "no".
AFAIK, all the rear brake parts are still serviceable. If I slack off
the e-brake adjuster, will this allow the shoes to re-position
slightly further in (away) from the drums which in turn would allow me
to adjust the shoes then properly adjust the e-brake?
As have others, I've seen first hand how caliper rebuild quality can be
poor.
Image of a rebuilt "new" pass. side caliper on my '81. A leak sprung
at the halves: http://tinyurl.com/pdbv7zn
As such, I can see that a big brake kit might be a good investment.
OTOH, for my '81, this means new uprights (knuckles) and possibly ball
joints etc.
Neil.
On Fri, May 10, 2013 at 10:39 AM, neil n <musomuso@gmail.com> wrote:
> At ~ 50-60 MPH, if I brake hard hands "off" the wheel, the van pulls
> to the right. Not severely but quite noticeably. Doesn't happen
> braking hard from ~ 30 MPH. Like I almost have to make the nose dive
> for the pull to happen.
> A shop checked the brakes, steering-front end components before this
> trip. Brakes checked out ok but they noted "upper ball joints have
> very very minimal play. Not a concern at this time." and that the sway
> bar bushings are cracked but "no safety concerns noted at this time".
> In spite of that, they said the front end was tight and ok.
> Almost all front end and brake parts have been replaced in recent
> years and don't have a lot of miles on them.
> I repaired the passenger side radius arm hole at the frame.
--
Neil n
Blog: tubaneil.blogspot.ca
'88 Westy http://tinyurl.com/c8rlw6p
'81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
Vanagon VAG Gas inline-VR Engine Swap Group:
http://tinyurl.com/d7gd5ej