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

imported_brackie · 07-07-2005, 09:00 PM

Nope...It's 100%

**Golf Loon** · 07-07-2005, 11:22 PM

How did you test the one way valve?

What about the brake bias valve under the back axle?

imported_brackie · 08-07-2005, 06:56 AM

Originally Posted by Golf Loon

How did you test the one way valve?

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

Originally Posted by Golf Loon

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** · 09-07-2005, 01:48 AM

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 · 09-07-2005, 06:18 AM

Originally Posted by Golf Loon

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.

**hiho** · 17-04-2006, 10:42 AM

Hi brackie,
have you sorted out the braking problem yet? I hope so. If not, there was something in the thread that caught my attention. You mentioned that the old MC was 12mm and the new one 9mm. If you are using the same booster on both MC's then then there could be a problem. The smaller diameter MC displaces less fluid per unit of distance travelled but can generate higher pressures in the braking line per unit of force applied to the pedal. As the booster is applying extra force to supplement the muscles in you leg, it may be applying enough force to cause the smaller diameter mc to travel further.

If you have a 9mm mc then you may not need the vacuum assistance at all as you now can generate higher brake line pressures for a given pedal effort, the trade off being longer travel.

On the subject of brakes, i have several GLD's that are being prepared for roadworthy. I have measured the discs and i have thicknesses of 7-8mm. this seems to be very thin. Do you know what the wear limits are for the GLD's? Also, if i go to a wrecker, are there any other cars with better fromt brakes that i could adapt to the Golf?
Thanks
Matt

imported_brackie · 17-04-2006, 11:41 AM

Originally Posted by hiho

Hi brackie,
have you sorted out the braking problem yet? I hope so.

It came good! I gave the car to our dairy hand and she's been driving it without mishap (apart from a duff water pump) for a few months. Can only assume that there was air trapped in some obscure place and it vented itself

If not, there was something in the thread that caught my attention. You mentioned that the old MC was 12mm and the new one 9mm. If you are using the same booster on both MC's then then there could be a problem. The smaller diameter MC displaces less fluid per unit of distance travelled but can generate higher pressures in the braking line per unit of force applied to the pedal. As the booster is applying extra force to supplement the muscles in you leg, it may be applying enough force to cause the smaller diameter mc to travel further.

If you have a 9mm mc then you may not need the vacuum assistance at all as you now can generate higher brake line pressures for a given pedal effort, the trade off being longer travel.

Good stuff! Yeah, your logic is good and this sort of info is good to have on our database. I still have the larger master cylinder re-sealed and in good order.

On the subject of brakes, i have several GLD's that are being prepared for roadworthy. I have measured the discs and i have thicknesses of 7-8mm. this seems to be very thin. Do you know what the wear limits are for the GLD's?

No, but I'll bet that someone on the forums does!

Also, if i go to a wrecker, are there any other cars with better fromt brakes that i could adapt to the Golf?

Look in "Interesting Articles" for the posts on

Originally Posted by hiho

Hi brackie,
have you sorted out the braking problem yet? I hope so.

It came good! I gave the car to our dairy hand and she's been driving it without misshap (apart from a duff water pump) for a few months. Can only assume that there was air trapped in some obscure place and it vented itself

If not, there was something in the thread that caught my attention. You mentioned that the old MC was 12mm and the new one 9mm. If you are using the same booster on both MC's then then there could be a problem. The smaller diameter MC displaces less fluid per unit of distance travelled but can generate higher pressures in the braking line per unit of force applied to the pedal. As the booster is applying extra force to supplement the muscles in you leg, it may be applying enough force to cause the smaller diameter mc to travel further.

If you have a 9mm mc then you may not need the vacuum assistance at all as you now can generate higher brake line pressures for a given pedal effort, the trade off being longer travel.

Good stuff! Yeah, your logic is good and this sort of info is good to have on our database. I still have the larger master cylinder re-sealed and in good order.

On the subject of brakes, i have several GLD's that are being prepared for roadworthy. I have measured the discs and i have thicknesses of 7-8mm. this seems to be very thin. Do you know what the wear limits are for the GLD's?

No, but I'll bet that someone on the forums does!

Also, if i go to a wrecker, are there any other cars with better fromt brakes that i could adapt to the Golf?

Look in "Intersting Articles" for the posts on

Originally Posted by hiho

Hi brackie,
have you sorted out the braking problem yet? I hope so.

It came good! I gave the car to our dairy hand and she's been driving it without misshap (apart from a duff water pump) for a few months. Can only assume that there was air trapped in some obscure place and it vented itself

If not, there was something in the thread that caught my attention. You mentioned that the old MC was 12mm and the new one 9mm. If you are using the same booster on both MC's then then there could be a problem. The smaller diameter MC displaces less fluid per unit of distance travelled but can generate higher pressures in the braking line per unit of force applied to the pedal. As the booster is applying extra force to supplement the muscles in you leg, it may be applying enough force to cause the smaller diameter mc to travel further.

If you have a 9mm mc then you may not need the vacuum assistance at all as you now can generate higher brake line pressures for a given pedal effort, the trade off being longer travel.

Good stuff! Yeah, your logic is good and this sort of info is good to have on our database. I still have the larger master cylinder re-sealed and in good order.

On the subject of brakes, i have several GLD's that are being prepared for roadworthy. I have measured the discs and i have thicknesses of 7-8mm. this seems to be very thin. Do you know what the wear limits are for the GLD's?

No, but I'll bet that someone on the forums does!

Also, if i go to a wrecker, are there any other cars with better fromt brakes that i could adapt to the Golf?

Look in "Intersting Articles" for the posts on Commodore/Magna conversions. I believe that Camira brakes can also be adapted. If your Mk1 diesel appears to have poor brakes check the vacuum pump. The diaphragms may be perforated (especially if you have excessive blow-by.)