Power brake assist missing and hissing

Muggins

Veteran Member
Joined
Jun 7, 2002
Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
So I read the threads to educate myself on loss of power brake assist and hissing when brake pedal is depressed. I took off the vacuum hose from pump to brake servo, examined it, epoxied what looked like cracks, and re-installed, without success. Also examined the check valve and small vacuum hose take-off from it, which looks normal. Still no power assist. I'm hoping against hope that it's NOT the brake servo.
Any advice on correcting this issue?
 

DivineChaos

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Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
first i would replace your vaccume lines then perform a brake booster test. you should be able to depress the petal once or twice with the car off. you might have a bad brake booster. they do fail. had one go and you loose power breaks and have to double foot the petal to get any breaking force. even with a leaking line you should have some power assist.
 

Muggins

Veteran Member
Joined
Jun 7, 2002
Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
I'm having no other performance issues (besides no brake power assist) in terms of engine performance, I get lots of turbo boost, so I don't see the point in replacing ALL the vacuum lines at this point.
My problem is, very difficult braking and I took off the vacuum hose that leads from the vacuum pump to the brake booster. I epoxied a couple of cracks and reinstalled, with no improvement in brake performance.
What I DO notice, is a hissing sound on brake pedal application, which I imagine is escaping air from the servo or the brake servo vacuum hose.
Would a defective brake booster/servo make that kind of hissing noise or is that ONLY characteristic of the vacuum line or check valve?
 

DivineChaos

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Location
Minnesota
TDI
mk6 jetta sportwagen tdi
I'm having no other performance issues (besides no brake power assist) in terms of engine performance, I get lots of turbo boost, so I don't see the point in replacing ALL the vacuum lines at this point.
My problem is, very difficult braking and I took off the vacuum hose that leads from the vacuum pump to the brake booster. I epoxied a couple of cracks and reinstalled, with no improvement in brake performance.
What I DO notice, is a hissing sound on brake pedal application, which I imagine is escaping air from the servo or the brake servo vacuum hose.
Would a defective brake booster/servo make that kind of hissing noise or is that ONLY characteristic of the vacuum line or check valve?
yes. it sounds like the brake booster is bad. But maybe we could get oilhammer's input on this. even with a leaky vac line you should have some power assist.
 
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Muggins

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Jun 7, 2002
Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
Watched a youtube video on a vacuum pump replacement for an ALH TDI and the new unit's vacuum nipple was solid in place, did not swivel or move like mine. So I cleaned up the nipple and surrounding area and epoxied it to prevent movement. It didn't help my problem. Still no power assist and I still hear this hissing coming from somewhere around the brake pedal when it's depressed.
 

Muggins

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Jun 7, 2002
Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
Because you still need a brake booster.

New booster costs a fortune and can't seem to source a reman unit. I tried to examine the booster as best I could with a mirror and feeling the bottom and backside for corrosion. Seems pretty solid, no rust or corrosion. I get the feeling it's a seal or o-ring or something like that causing the vacuum leak. Are there no seal kits available to repair the booster?
 

2.2TDI

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May 1, 2011
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TDI
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Go to the scrap yard and get a booster, there are so many mk4s at 3 scrap pull it your self salvage yards in Hamilton, it's hilarious. A booster is like 30 bucks, dirt cheap, and if you happen to have bad luck and get a bad one, all scrap yards have an exchange policy

Just so you get an idea, this 02 beater I just picked up had a leaking rack. I got a complete rack, 2 power steering lines, the reservoir and the power steering pump for 80 bucks. I didn't feel like dropping a subframe and rack on the ground on my back so I found a competent shop that replaced the rack, with alignment, for 280...360 bucks for a rack installed. Reman racks go for 300 alone
 
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oilhammer

Certified Volkswagen Nut & Vendor
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Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
New booster costs a fortune and can't seem to source a reman unit. I tried to examine the booster as best I could with a mirror and feeling the bottom and backside for corrosion. Seems pretty solid, no rust or corrosion. I get the feeling it's a seal or o-ring or something like that causing the vacuum leak. Are there no seal kits available to repair the booster?

None of this changes the fact that your car still needs a brake booster. Sorry.

Not sure how it is in Canada, but here I can get a brand spanking new Ate booster for less than $200. I would not call that a "fortune", however as pointed out there are certainly plenty of used ones out there. You do need to make sure to get the correct one, as there are some choices based on brand of master cylinder, ESP or not, etc.
 

Muggins

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Jun 7, 2002
Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
Thanks for all those tips, guys!
A new booster from the stealer is $591 + tax.
Aftermarket it's $385 + tax.
The wrecker wants $75 + tax with 90 warranty.
 

2.2TDI

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Thanks for all those tips, guys!
A new booster from the stealer is $591 + tax.
Aftermarket it's $385 + tax.
The wrecker wants $75 + tax with 90 warranty.
75 seems expensive but I'm guessing this is one near you that isn't a you pull it wrecker

If you go to something like kenny u pull in hamilton and grab it yourself, it's 24 bucks plus tax. If you take the booster and master cylinder it's 40 bucks plus tax

https://www.kennyupull.com/en/price-list/Hamilton

Anyways for an extra 50 bucks if it's nearby you and you don't have to pull it, it's still a good price

Also, if you want aftermarket, just go to rockauto... cheapest one is 175 plus tax... with shipping you'll likely still come out cheaper

Best of luck
 

Muggins

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Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
Cookstown Auto, the place nearest me which I called, is a you-pull-it yard, with a booster off-car.
I checked Rockauto's website and they list a reman unit from Cardone for about $250 CAD without core exchange. Their non-ESP booster which is what I need, costs MORE than their ESP-equipped units.
 

2.2TDI

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Cookstown Auto, the place nearest me which I called, is a you-pull-it yard, with a booster off-car.
I checked Rockauto's website and they list a reman unit from Cardone for about $250 CAD without core exchange. Their non-ESP booster which is what I need, costs MORE than their ESP-equipped units.
That's really expensive for a you pull it wrecker... But since Cookstown is pretty close to barrie it's probably worth it just in the time you'll save driving all the way to Hamilton and back.

Anyways hope you get your issue solved
 

Muggins

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Location
Barrie, Canada
TDI
02 Golf GL 4dr 5spd
Thanks guys.
Taking it to Brandon at DCB Motors in Orillia today to check it. He says he doubts it's the booster. Hope he's right.
 

Muggins

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Location
Barrie, Canada
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02 Golf GL 4dr 5spd
Do let us know, i'm curious what it ends up being
Well it looks like Brandon's doubts were sadly misplaced because it strongly appears to be a bad booster.
Vac pump checks out strong - 30 psi
Vac hose to booster is solid - it releases vacuum audibly when removed from booster.
Bought a really ratty looking booster (looks WAY worse than mine) for the outrageous sum of $85 CAD with a 90 day warranty not including labour. Now I have to book an appt to have it re and re'd.
 

Johhny04

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Location
Markham, Ontario
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2003 Jetta TDi
Well it looks like Brandon's doubts were sadly misplaced because it strongly appears to be a bad booster.
Vac pump checks out strong - 30 psi
Vac hose to booster is solid - it releases vacuum audibly when removed from booster.
Bought a really ratty looking booster (looks WAY worse than mine) for the outrageous sum of $85 CAD with a 90 day warranty not including labour. Now I have to book an appt to have it re and re'd.
Looks like oilhammer was right. Brake booster.

Hope your experience in Orillia goes well! Is he actually allowed to work on the vehicle or will his "apprentice" be completing the work?
 
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2.2TDI

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Well it looks like Brandon's doubts were sadly misplaced because it strongly appears to be a bad booster.
Vac pump checks out strong - 30 psi
Vac hose to booster is solid - it releases vacuum audibly when removed from booster.
Bought a really ratty looking booster (looks WAY worse than mine) for the outrageous sum of $85 CAD with a 90 day warranty not including labour. Now I have to book an appt to have it re and re'd.
Oh well as long as it works. You'll never see it so looks don't matter. The price sucked but again for not having to drive to Hamilton it was worth it. Hopefully this used booster will solve the issue

Cheers
 

Muggins

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Location
Barrie, Canada
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02 Golf GL 4dr 5spd
Oh well as long as it works. You'll never see it so looks don't matter. The price sucked but again for not having to drive to Hamilton it was worth it. Hopefully this used booster will solve the issue

Cheers
Yes, thanks!
It appears I ran out of other options. Now as long as the shop doesn't come up with any other surprises with the install.
What a rigmarole at the wreckers. Cannot step into the building. Guy outside takes your order and comes back out with the part. You-pick is history.
 

2.2TDI

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Yes, thanks!
It appears I ran out of other options. Now as long as the shop doesn't come up with any other surprises with the install.
What a rigmarole at the wreckers. Cannot step into the building. Guy outside takes your order and comes back out with the part. You-pick is history.
That's odd, they should be open but I guess every yard is different...all.3 yards I've been to in Hamilton recently are open for pull it yourself. Pulled myself a few goodies in the last few weeks
 
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