Re: bleeding brakes and pdwa valve thing

"Mr.Nice." <[email protected]> wrote in message
news:[email protected]...
> My 110 has a valve thing
> http://www.markvarleyphoto.co.uk/pdwa.jpg
> it blockes off one brake circuit if there is a leak.
> I'll be bleeding the system soon and I expect it'll be easier if I can
> stop this valve thing from doing it's thing.
>
> How do I lock it in the center or otherwise prevent it blocking the
> circuit I'm using?

Thats the shuttle valve ... all it does is have a sliding piston inside
which when it moves one way or the other **should** activate a switch which
illuminates the "Fail" light on the dashboard.

It won't actually stop any fluid loss or owt.. As the Master cylinder should
have two chambers and the reserviour is also split in to two (if you look
inside you'll see a divider) It should in effect provide two systems. One
front and one rear. The only common factor being the shuttle valve and the
occasional leak betweeen the two should the master cylinder seals fail in
some bizarr manner allowing fluid to pass between the two supposed systems.

It's not unknown for one system to empty into the other in this situation.
On a common garden Landie you wouldn't notice, but on a 101 with 2 seperate
(physically) reserviours you end up with an empty reserviour and a full one.

So you shouldn't need to touch the shuttle valve at all.. Just bleed away as
if it weren't there.


Lee D

"Mr.Nice." <[email protected]> wrote in message
news:[email protected]...
> So when I open a bleed screw the valve thingy won't thing "eyup!
> leak!" and shuffle accross and block that circuit off = no fluid
> pushed into that circuit = not bled?

I've never had one shuttle that far, When I fitted new lines on Percy the
Shuttle valve didn't present any problems.


Lee D
--

www.lrproject.com

Workshop photos from Landrover repairs
& other such tinkerings.
Home of Percy the Jag powered Landrover

Mr.Nice. wrote:

>Twas Sun, 26 Sep 2004 14:03:21 GMT when "Lee_D" <[email protected]>
>put finger to keyboard producing:
>
>
>
>>"Mr.Nice." <[email protected]> wrote in message
>>news:[email protected]...
>>
>>
>>>So when I open a bleed screw the valve thingy won't thing "eyup!
>>>leak!" and shuffle accross and block that circuit off = no fluid
>>>pushed into that circuit = not bled?
>>>
>>>
>>I've never had one shuttle that far, When I fitted new lines on Percy the
>>Shuttle valve didn't present any problems.
>>
>>
>>Lee D
>>
>>
>
>Righty then, I'll get an eezibleed early next week and see what comes
>of it.
>
>
>Regards.
>Mark.(AKA, Mr.Nice.)
>
>


Hi Mark,

Been lurking here to see what the others had to say about your shuttle
valve, and it pretty well matches my experience - I just didn't want to
misslead you into bleeding away like mad on the basis of my limited RRC
experience (very tired Y plate diesel conversion and becoming tireder by
the minute Vogue EFi).

Hope you enjoy the Eezibleed and find it as easy to use as I do.

I'd still give really serious thought to a set of Goodrich hoses.

Rgds Richard

On Sun, 26 Sep 2004 12:59:26 GMT, "Lee_D" <[email protected]> wrote:
>> My 110 has a valve thing
>> http://www.markvarleyphoto.co.uk/pdwa.jpg
>> it blockes off one brake circuit if there is a leak.
>> I'll be bleeding the system soon and I expect it'll be easier if I can
>> stop this valve thing from doing it's thing.
>>
>> How do I lock it in the center or otherwise prevent it blocking the
>> circuit I'm using?
>
>Thats the shuttle valve ... all it does is have a sliding piston inside
>which when it moves one way or the other **should** activate a switch which
>illuminates the "Fail" light on the dashboard.
>
>It won't actually stop any fluid loss or owt.. As the Master cylinder should
>have two chambers and the reserviour is also split in to two (if you look
>inside you'll see a divider) It should in effect provide two systems. One
>front and one rear. The only common factor being the shuttle valve and the
>occasional leak betweeen the two should the master cylinder seals fail in
>some bizarr manner allowing fluid to pass between the two supposed systems.

I have a simple remedy for those bloody shuttle valves. Remove it and
fit t-pieces instead. Keep the brake lines separate - you'll know if
one circuit has gone the moment you put your foot on the brake anyway
- it won't do an awful lot.

If the seals in it are dodgy, which after 15-20 years or so they will
be, it makes bleeding impossible, as fluid leaks from one circuit to
the other during the bleeding process.

As for "locking it", you can't. You have to bleed each circuit
separatly, allowing the shuttle valve to do it's thing and the lamp to
come on. After bleeding you then return to the previous end to which
you have just bled, and slowly bleed some more fluid out, untill the
lamp goes out, then the shuttle valve is in the correct position.

Alex