Date: Sun, 1 Sep 2019 11:47:25 -0700
Reply-To: Alistair Bell <albell@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Alistair Bell <albell@SHAW.CA>
Subject: Re: Pressure bleeding brakes questions
In-Reply-To: <8560E7D5-BBB7-420C-982A-04AC3DA05648@NBNet.nb.ca>
Content-Type: text/plain; charset=utf-8
Hi,
Yeah I’ve seen various thingies for the active brake proportioning in other vehicles. The van one is easy to over look, it’s just a cast junction thing in the frame. I’ve been going on the belief that inside it there is a ball bearing that occludes the lines to the rear brakes when the van assumes a greater than specified angle , ie on hard braking.
I know there is a specific angle the valve has to mounted at.
Alistair
> On Sep 1, 2019, at 11:38 AM, Roy Nicholl <RNicholl@nbnet.nb.ca> wrote:
>
> Alistair:
>
> Not sure why your post created a “need to know” … let alone a “need to share” but here is what is in our stable:
>
> The lever on the proportioning valve on the wife's Jetta is attached to the rear beam … so presumably as the ass-end lifts it changes the flow of fluid to the rear brakes.
>
> My LT has load sensors which perform a similar role of adjusting the brake bias as more load is placed on the truck.
>
> The ’88 Westy does not have a lever on its proportioning valve. Neither does the Thing or the ’66 Westy (which has been retrofitted with a dual chamber master cylinder).
>
> My ‘04 TDi wagon looks like there was once a lever attached to the rear beam, that has since rusted away (probably should change that ;))
>
>
>
>> On 01-Sep-2019, at 14:40, Roy Nicholl <RNicholl@NBNet.nb.ca> wrote:
>>
>> I had to go look … the Jetta does have a lever on the side - presumably for adjusting the bias between front and rear.
>>
>>> On 01-Sep-2019, at 14:37, Roy Nicholl <RNicholl@NBNET.NB.CA> wrote:
>>>
>>> No, I’m sure you’ll fancy something out of aluminium.
>>>
>>> BTW: I don’t think any of our six VWs have lever on the proportioning valve, but I haven’t had cause to crawl under the wife’s Jetta yet.
>>>
>>>
>>>> On 01-Sep-2019, at 14:30, Alistair Bell <albell@SHAW.CA> wrote:
>>>>
>>>> I’ll give it a go Roy . The “German Bentley “ was the only place i had come across that method until your reply.
>>>>
>>>> But don’t have any hockey sticks to use, don’t tell anyone Roy, I’ll be deported :-)
>>>>
>>>> Alistair
>>>>
>>>>> On Sep 1, 2019, at 10:19 AM, Roy Nicholl <RNicholl@nbnet.nb.ca> wrote:
>>>>>
>>>>> Alistair:
>>>>>
>>>>> For a couple of decades (or more) I've used a custom-fitted shaft from a Victoriaville stick (the same one I used as cruise-control in the ’66 Westy) to slightly depress the brake pedal when bleeding the brakes (a local VW mechanic - imported from Germany in the 70s - recommended this approach years ago.
>>>>>
>>>>>
>>>>>> On 01-Sep-2019, at 13:49, Alistair Bell <albell@SHAW.CA> wrote:
>>>>>>
>>>>>> Time to flush the brakes, it’s due and an event on last trip made it even more time :-) I might post a description of what happened, but for now I have some questions.
>>>>>>
>>>>>> I have been using a home made pressure bleeder for years, and it works fine. Nothing complicated, just a garden sprayer modified with pressure gauge and fluid reservoir cap with bulkhead fitting .
>>>>>>
>>>>>> Some years ago I noticed in one of the German language manuals I have, that they go into more detail on pressure bleeding than the English Bentley. One thing especially intriguing, that is a special tool that goes between the driver’s seat and the brake pedal. It’s just and adjustable bar and it seems the brake pedal is pushed , not full way down, during pressure bleeding.
>>>>>>
>>>>>> I kinda thought that the passages from the brake mc to the reservoir would be blocked during brake pedal depression and thus preventing the pressurized ( during bleeding ) fluid in reservoir from travelling thru system. Maybe the idea is only partial brake pedal depression?
>>>>>>
>>>>>> Any thoughts?
>>>>>>
>>>>>> Another query is from the English Bentley, 47-8. Procedure calls for disconnection of the brake booster vacuum line at the check valve when pressure bleeding. Again I haven’t done that before. And again I don’t know why this should be needed.
>>>>>>
>>>>>> Same page of Bentley, and I think this is a mistake. Calls for the pressure regulator lever to be pushed towards rear wheels. I’m pretty sure our vans don’t have a lever on the pressure regulator ( the proportioning valve under the van ).
>>>>>>
>>>>>> Alistair
>>>>>
>>
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