THE brake story...continued...HELP!

[Golf Loon]

I`ve got a spare Golf booster. Smaller diameter than your one, but it will fit and will be better than none. Up to you.

[imported_brackie]

Brake expert

Took the old girl to Devonport today. No booster so hard on the right leg, but she stopped just fine! He looked at it and reckons the booster is OK. He says that there is still air in the system and that when the booster is connected the extra assistance makes the pedal go to the floor. Doesn't make much sense to me. He recommended using mole grips on the flexible hoses to isolate each wheel in turn and identify where the air lies. I'll try it tomorrow. This is ridiculous!

[el_foolio]

yeah, my girlfriends golf had no booster for a while, still stopped just fine

[Golf Loon]

Take it somewhere that has a pressure bleeder machine. Saabs are the same, keep bleeding and bleeding the system and it wont work, then as soon as you pit the line under pressure, works straight away.

[imported_brackie]

Exploding reservoir??

I asked him about that and he said it would blow the plastics apart. Recommended vacuuming it from the bleed nipples.

[imported_brackie]

Take it somewhere that has a pressure bleeder machine. Saabs are the same, keep bleeding and bleeding the system and it wont work, then as soon as you pit the line under pressure, works straight away.

Hey... Just an idea... What about bleeding with the engine running and the booster connected? That's really doing the same thing.
Also, he said to help get the air out of the MC, park on a steep slope (nose pointing down) and work the brake pedal. This brings the MC level (it's on an upslope to the front when the car is level) and moves the compensators so air works its way upwards and back into the reservoir.

What do you guys reckon about these 2 gems??

[Golf Loon]

Do they work?
Find someone with the vacuum machine and apply suction to all the lines.

[imported_brackie]

The saga continues....

I thought I'd better get back to that caliper with it's bleed nipple problem. For those who've disengaged themselves form this thread (and who could blame you?....Its been a long one!) I had a seized bleed nipple that broke off and I had to drill out and plug the orifice. I discovered a retired (semi) engineer in Devonport who sleeved master cylinder and did all sorts of other magic on braking systems. I gave him the caliper and he put in an insert and new bleed nipple. So, next opportunity I get I'll go through the whole bleeding process again and hope and pray.......Oh If anybody wants this sort of modification/repair done he's only too happy to oblige. Even with postage to and from Tassie you'll end up paying only a fraction of the price of a new one. I'll put his contact details in "Recommended Repairers".

[imported_brackie]

Not finished yet...

So, I bled it again. Hard pedal at the top until the engine is strarted. (Been here before??) Decided to take Looney's advice and get it vacuum or pressure bled. Took the car to a workshop today and the guy did just that. Claims he got some air out but it felt and stopped just the same when I drove it home. So, for $66 (1 hour's labour!) I am no further forward. He said, "It's the booster". Bulls**t! There are no vacuum leaks. There is full assistance. There is no extra free play in the pedal. The engine speed doesn't change when the brakes are applied at idle. It can't be the booster. If the diaphrgm is punctured there will be a) higher tickover as there is a loss of vacuum b) no assistance because the diaphragm is perforated. There's plenty of assistance. Guy at the workshop said the booster would have to be sent to the mainland to be repaired. $350 + freight + he would have to fit it to preserve warnanty. So a $1000 job to keep a car that's worth $1000 max. ????

[20v kit car]

the one way valve ..the one way valve ......the one way valve

[imported_brackie]

Valve

Nope...It's 100%

[Golf Loon]

How did you test the one way valve?

What about the brake bias valve under the back axle?

[imported_brackie]

Valve.

How did you test the one way valve?

Removed it and blew/sucked both ways. It holds.

What about the brake bias valve under the back axle?

Works as far as I can tell. When the brakes were pressure bled in the workshop he did it "on the level". Anyway, how could it be involved? I know what they do but I don't know enough about how they work. Do you agree with my logic about the booster?

[Golf Loon]

Yes I agree about the booster, but remember what the Haynes manual says.."never omitt any part from your troubleshooting even if you know it to be good"

Where else can air come into the system guys if the booster is ok?

[imported_brackie]

How did you test the one way valve?

Took out the valve altogether and plumbed direct. For some reason Audi has a complex vacuum takeoff from 3 points on he intake side. The valve itself is actually mounted on a "T" and only operates on 1 of the 3 hoses that go to the manifold Duh... Should have taken a pic. But anyway, it made no difference so I put it back.