Was driving my 01 Jetta ALH and the brake operation was fine and then randomly in my drive they got extremely stiff. I have replaced the line that goes from the vacuum pump to the brake booster and although mine was not in the best of shape it did not fix my problem. I took the line off the pump and started my car and held my thumb over to make sure there was suction. There is suction but it is not really hard by any means, I don't know how many inches it's supposed to suck. The brakes will feel normal for one pump after a while down the highway, I'm assuming its having enough time to build up pressure. Is my pump or booster toast? Will be getting a lot more in depth in my diagnosis this weekend when I find a heated garage cause playing under the hood outside is not fun in Michigan in January lol.
Stiff Brakes
- Thread starter spangar
- Start date
Nevada_TDI
Top Post Dawg
It is both possible and likely your vacuum pump has bit the dust. I wonder if you have noticed any power loss lately from lack of vacuum to the turbo actuator? Even though there are no "rebuild" kits for the ALH vacuum pump, they are really easy to fix. How do I know, I fixed mine when it died. All you need is one o-ring and a couple of hours. While you have the vac pump out there is a inexpensive seal that you should replace also, IIRC, it is less than $5.00
03TDICommuter
Veteran Member
Can you point me to a thread on the fix? I need to remove mine and tighten the loose nipple and figure while I'm in there I would 'freshen' it up.
gallaj01
Veteran Member
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Before you replace your vacuum pump I would replace all of the vacuum hose segments, if these have never been replaced. I recently worked on a car that was had intermittent brake stiffness, power loss, and a high flow EGR code all around the same time. The vacuum line to the turbo actuator had a small crack which was leaking the vacuum from the entire system. Once all of the lines were replace all three issues immediately went away.
Nevada_TDI
Top Post Dawg
If after replacing the vacuum lines if the problem still persists it could be that the nipple has wiggled itself loose, or it could be the factory o-ring in the pump had dried and cracked. I will look for a how-to video for your vac pump at some point tomorrow.
DefconZero
Well-known member
All the previous comments are on point. I've been dealing with intermittent brake issues myself for the longest time and it seems the MK4 vacuum platform is a pain when it starts acting up.
Initially replaced the hose between pump and booster...no change
Replaced all vacuum lines in the system...no change
Tried fixing the nipple....no change
Replaced pump with used unit from scrap yard...fixed!...for a while anyway.
Then my brake booster died...so replaced that...
Now back to having vacuum issues...
Next step is pump replacement with new unit.
Initially replaced the hose between pump and booster...no change
Replaced all vacuum lines in the system...no change
Tried fixing the nipple....no change
Replaced pump with used unit from scrap yard...fixed!...for a while anyway.
Then my brake booster died...so replaced that...
Now back to having vacuum issues...
Next step is pump replacement with new unit.
Nevada_TDI
Top Post Dawg
There is a 99% chance if you buy the correct o-ring you can fix it yourself. The required o-ring is 74mm x 2.5mm, IIRC the BRM oil filter o-ring is the correct one. Once you have the pump out it's 3 bolts out, degrease, fit in new o-ring, tighten down the three bolts and put back onto engine. I fixed mine myself as I didn't have $200.00 to buy a new one.
LINK TO VIDEO:https://www.youtube.com/watch?v=7aRX4gfcpek
LINK TO VIDEO:https://www.youtube.com/watch?v=7aRX4gfcpek
Last edited:
Nevada_TDI
Top Post Dawg
What year is the BRM 2005-2006? I'll see if the auto parts store has a filter that will fit it.
Replaced the vacuum pump o-ring with the o-ring from the filter from the BRM. Seemed like it needed it, o-ring from pump was very flat but still did not solve the problem. I do not understand how the vacuum pump can go bad, the inside of that thing kind of blew my mind. Turned into a project tonight as i replaced all the valve cover bolts, found a pipe on my turbo that was pretty loose, and also found my car is leaking oil from the camshaft sensor. Knew I had a small leak/drip but could not find the spot. Anyways I'm starting to think I'm going to have to replace the pump or the brake booster to solve my power brake issue. Did not replace any of the vacuum lines so I could do that but I do not like playing the guess and change game cause it can get pretty expensive.
joep1234
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Before you replace any other parts, bleed your brakes using VCDS to activate the ABS pump as you bleed them. I had the same symptoms on my '04 Beetle. They would work sometimes perfectly and then would be hard and not stop as they should. I ran 1 1/2 quarts DOT 4 through the system as I bled all 4 wheels. The fluid that came out bleeding with the ABS pump was black. Once it ran clear on all 4 wheels, the brakes have been working strong as ever for the last 6 weeks. Knock on wood that took care of my problem. I would try that before you throw any more parts at it.
maxmoo
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if the vacuum lines are original they probably need changing anyway and they are not very expensive and easy to do compared to a brake booster.
joep1234
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If your turbo is functioning properly, there is most likely not a problem with vacuum. They both use the same supply thus if one is having trouble, the other should be having trouble as well. How is your power?