Date: Fri, 16 Jul 2021 18:22:40 -0700
Reply-To: Neil <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Neil <musomuso@GMAIL.COM>
Subject: Re: Rear brake drum/shoe replacement - bleed brakes? grrr
In-Reply-To: <b2d5ad91-ce79-79be-15c8-f23e75d3d4c9@williamsitconsulting.com>
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I'd think the wheel cylinder pistons have to get pushed out of the
bore before air could get in via cylinders.
Theory: shoes aren't centred to drum yet but part of the shoe linings
are touching the drums thus making the e-brake feel normal. A lack of
correct lube might limit normal up/down/laterally movement of shoes.
What I'd do:
- apply lube as needed
- in lieu of a brake shoe caliper, mark center of each shoe, measure
distance lining to lining with tape measure?
- adjust shoes out so significant drag is felt at each wheel
- depress brake pedal a few times; does it now feel more normal?
- if need be, adjust shoes in a little so the drums drag, but less so.
Check pedal feel.
Setting the correct gap between e-brake cable end at lever on shoe is critical.
Sticking e-brake cable(s) could interfere with shoe adjustment. If
that's happening, dis-engage the cable from each lever at each shoe,
adjust shoes?
A long shot guess: too much distance between shoes and drums allowed
the brake pedal to travel further than normal allowing the master
cylinder seals to move past dirt in the bore causing MC failure.
Neil.
On 7/16/21, Steve Williams <steve@williamsitconsulting.com> wrote:
> Hi,
>
> I just replaced the rear drums and shoes on my 91 Westy.  I tried to
> follow the Bently to measure the adjuster "preset", but I don't have
> anything to measure it properly.
>
> I played with winding out the adjuster until my brake shoes just rubbed
> on the drum, then backed it off until they didn't rub anymore. Well, a
> tiny scrape at one point where they are out of round a bit, but I figure
> that will wear down shortly.
>
> After doing this with both wheels, the parking brake feels very good,
> similar to how it was with the old shoes/drum.
>
> However, my brake peddle is soft, like there is air in it. The only way
> I think this could have happened is if I let the slave pistons extend
> too far while I was messing around putting the shoes on. Does this make
> sense?
>
> It is soft, and it does pump up, so I'm pretty sure it's air. But it
> should only be in the slave cylinder. I checked the brake fluid
> resevoir and it's above the MAX, which is what I would expect with new
> shoes on and the pistons further into the cylinder.
>
> I've never had to bleed the brakes on my westy.
>
> I do have a generic "vacuum" pump (manual) that comes with a device to
> capture brake fluid. Assuming I can get the bleed screw open, can I
> just use that?
>
> I am alone, so it's hard to do it how I used to (on other vehicles).Â
> Historically I've run a hose to a jar of brake fluid, had a second
> person pump the brake pedal, open the bleed screw, let the air/fluid
> escape and repeat as necessary.
>
> Thanks for any input!
>
> Cheers,
> Steve Williams
>
--
Neil n
VE7TBN
1988 Westy 50º ABA swap: https://tinyurl.com/yap5hpwt
1981 Westy 15º ABA swap: https://tinyurl.com/y9n4xob8
VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>
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