Shenandoah
Veteran Member
- Joined
- Jan 9, 2008
- Location
- Shenandoah Valley, VA
- TDI
- 2005 Jetta Wagon; 2005 Beetle; 2004 Jetta; 2002 Golf (three of them); 2002 Jetta Wagon; 2000 Audi TT->TDI; 1999 Beetle
Folks,
This is my 2000 Audi TT > ALH conversion and my daily driver. The other day when I came home from work I noticed my brakes felt "soft". The pedal seemed to travel closer to the floor than previously. I also noticed a "pffffff" sound when I put the brakes on. No noise when the pedal came back up. Braking was ok, it's just the pedal traveled further than I was used to.
I inspected the hard line between the vacuum pump and the brake booster. No cracks or leaks. I know the check valve is bad, but for this test, it's not in use. I put the hard line back on and connected my might vac to the nipple on the check valve. Started the car and have 27" of vacuum at idle. If I step on the brake pedal and hold it, I loose about 3-4" of vacuum and the vacuum holds steady. When I let up on the pedal, vacuum drops down to about 10"-15" and takes 10-12 seconds before it's back up to 27" vacuum.
If I pump the brakes rapidly 4-6 times, vacuum drops down to almost zero. Once I stop pumping the brakes it takes about 10-12 seconds for vacuum to build back up to 27".
I've got several VWs and don't notice the "pffffff' sound on them when I put the brakes on. If I listen closely I can hear a slight "pfffff' sound on the others, but no where near as noticeable on the TT. My guess is the brake booster is going bad?
Does it sound like the booster is failing? If not, what else should I check. Thank you.
Eric
This is my 2000 Audi TT > ALH conversion and my daily driver. The other day when I came home from work I noticed my brakes felt "soft". The pedal seemed to travel closer to the floor than previously. I also noticed a "pffffff" sound when I put the brakes on. No noise when the pedal came back up. Braking was ok, it's just the pedal traveled further than I was used to.
I inspected the hard line between the vacuum pump and the brake booster. No cracks or leaks. I know the check valve is bad, but for this test, it's not in use. I put the hard line back on and connected my might vac to the nipple on the check valve. Started the car and have 27" of vacuum at idle. If I step on the brake pedal and hold it, I loose about 3-4" of vacuum and the vacuum holds steady. When I let up on the pedal, vacuum drops down to about 10"-15" and takes 10-12 seconds before it's back up to 27" vacuum.
If I pump the brakes rapidly 4-6 times, vacuum drops down to almost zero. Once I stop pumping the brakes it takes about 10-12 seconds for vacuum to build back up to 27".
I've got several VWs and don't notice the "pffffff' sound on them when I put the brakes on. If I listen closely I can hear a slight "pfffff' sound on the others, but no where near as noticeable on the TT. My guess is the brake booster is going bad?
Does it sound like the booster is failing? If not, what else should I check. Thank you.
Eric