bleeding brakes and pdwa valve thing

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

Twas Sun, 26 Sep 2004 12:59:26 GMT when "Lee_D" put finger to keyboard producing:

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?

Regards. Mark.(AKA, Mr.Nice.)

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

Twas Sun, 26 Sep 2004 14:03:21 GMT when "Lee_D" put finger to keyboard producing:

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

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

Twas Sun, 26 Sep 2004 17:22:49 +0100 when Richard Savage put finger to keyboard producing:

If this doesn't sort the problem then I'm going for new cylinders on the back and shoes too and new hoses also. Being short of cash means cheapest route required, I can justify the price of the eezibleed as I'm not as mobile as I could be and it'll make life far easier. watch this space as they say.

Regards. Mark.(AKA, Mr.Nice.)