06 Jetta BRM - Hard Brake Pedal + No Boost/Limp Mode

usmcracing

Well-known member
Joined
May 19, 2008
Location
Sharpsburg, Ga
TDI
2006 Jetta BRM
I have a 2006 Jetta BRM manual trans with around 200k miles on engine and 282k on chassis. Long story short with the mileage difference, I purchased the car with 272k miles and a connecting rod hanging outside of the engine block. I paid $300 for the car from my sister n law and had junk yard engine installed for $1800. The timing belt was also done at time of engine install in Jan this year.

After driving the car I noticed that the brake pedal was only for the first few presses when coming to a stop. I suspected there was vacuum leak or possible failing brake booster (I changed the booster in my old 03 TDI and don't want to do that again). Other then the brake issue the car ran great with tons of power or at least compared to the 03 Jetta Wagon TDI I had before.

Now for the problem - Monday I drove from Atlanta to Philadelphia, I've made this trip a few times since having the engine replaced. It ran great as normal but on the way back to ATL I was south of DC and proceeded to pass a semi truck and there was zero power to accelerate. I go to pull off of the interstate and the brake pedal is hard but I was able to safely stop. I checked everything and looks for anything obviously wrong around the vacuum pump/lines. The only thing that I saw that wasn't there before was there is a slight oil coming from between the vacuum pump/head/valve cover. I carefully drove to the first exit and gas station to look over the car more thoroughly but everything looked fine and normal, all of the intake pipping was intact, oil level was normal, coolant level/temp normal, and the engine idled/revved normal. When I shut the engine off and restart/drive it feel to have about 80% power and I car hear the turbo spool but after few mins it goes back to no boost/limp mode. I was able to drive the car a family members house about 100 miles away without any other issues.
I haven't pulled any engine codes yet but I'm sure it's going to have P0299 in there. My first thought was to order a vacuum pump/tandem pump but after reading a few threads here I think I'm going to check a few other things first.

My short list is the following,

Pull the fault codes
Valve Cover/Vacuum camber
N75 Valve (I don't think this is the problem due having two issues)
Vacuum/Tandem Pump oil leak (Gasket?)
Reinspect all of the turbo/intake pipping
Check Vacuum at the turbo actuator (again I don't think this is problem)

My gut is telling me that it's either the Vacuum Pump or Vacuum leak that is going to cause both the brake issue and limp mode issue.
Any advice will be much appreciated.


Thanks,

Steven
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Booster vacuum tube assembly, either a split somewhere or the nipple that goes to the vacuum driven bits on the engine broke off.

In about 1/10th the time it took to make your post, you could have likely opened the hood and looked at that part at least. ;) I doubt the vacuum pump itself suddenly totally died.

I think the part number for that tube on t he BRM is 1K0-612-041-GQ
 
Last edited:

usmcracing

Well-known member
Joined
May 19, 2008
Location
Sharpsburg, Ga
TDI
2006 Jetta BRM
Booster vacuum tube assembly, either a split somewhere or the nipple that goes to the vacuum driven bits on the engine broke off.

In about 1/10th the time it took to make your post, you could have likely opened the hood and looked at that part at least. ;) I doubt the vacuum pump itself suddenly totally died.

I think the part number for that tube on t he BRM is 1K0-612-041-GQ
Thanks for the advice but as I stated in my post the first thing I did was open the hood and checked nearly every vacuum line/hose/tube that was visible and everything was good and nothing looked cracked. That was on the side of the interstate, I drove a few miles to a gas station and checked everything again but still didn't find anything.

Taking your advice I checked the T at the vacuum pump, the tube/hose that goes to the brake booster, and the smaller hose that goes to the valve cover vacuum camber. No cracks but they were full of oil, I started the engine with the T off the vacuum pump and there is zero vacuum.

I don't think the vacuum pump just suddenly died, also in my original post (part of the back story) I described how the brake pedal was only good for a few presses before it would get hard. I have experience with diesel engines, I was a diesel mechanic in the USMC for 13 years and have owned a few TDI's and F250/350 trucks. I've had vacuum pumps fail without warning on a 1995 F350 7.3L powerstroke and one several 2013 F250's.

Anyone else have any other ideas? I am still thinking the vacuum pump is bad.

Thanks

Steven
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Yeah, I have seen a vacuum pump suddenly die on a couple old 6.2L GM trucks, the old VAG cars (with the old style diaphragm pumps) and even ones on the Ford/IH 6.9L and 7.3L IDI engines... but never on a BRM.

Obviously if yours has no vacuum, it isn't working. What I HAVE seen is the shaft break on an ALH, but the BRM uses that same shaft to run the fuel pump, and your car has not quit running.

That engine uses what is called a tandem pump, if that is what you need. I've replaced a few of those from leaking fuel, just never from lack of vacuum.
 

usmcracing

Well-known member
Joined
May 19, 2008
Location
Sharpsburg, Ga
TDI
2006 Jetta BRM
Yeah, I have seen a vacuum pump suddenly die on a couple old 6.2L GM trucks, the old VAG cars (with the old style diaphragm pumps) and even ones on the Ford/IH 6.9L and 7.3L IDI engines... but never on a BRM.
Obviously if yours has no vacuum, it isn't working. What I HAVE seen is the shaft break on an ALH, but the BRM uses that same shaft to run the fuel pump, and your car has not quit running.
That engine uses what is called a tandem pump, if that is what you need. I've replaced a few of those from leaking fuel, just never from lack of vacuum.
Thanks, I was glad it continued to run and was able to limp somewhere to work on it. Which is over 100 miles.
 

Bob S.

Top Post Dawg
Joined
Aug 17, 2006
Location
Central MD.
TDI
A B4V, some ALHs & BRMs
My suspicion is the same as OilHammer's. That vacuum tube is a common failure & your at about the mileage that it occurs.
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
I would suggest buying a Mitey Vac and actually trouble shooting the vacuum system. The problem OH eluded to would have been easily found as well as any other issues in the vacuum system. I don't like replacing anything without verifying the failure, so why do people change parts by consensus anyway?

As an aside, I would have 99.9999% confidence in OH's recommendation.
 

usmcracing

Well-known member
Joined
May 19, 2008
Location
Sharpsburg, Ga
TDI
2006 Jetta BRM
My suspicion is the same as OilHammer's. That vacuum tube is a common failure & your at about the mileage that it occurs.
I took the T and tube off and inspected it and there are no signs of cracking. While I don't have a vacuum gauge/test pump I did apply some air psi and didn't notice any leaks.

I don't like replacing parts without knowing they are bad either. The fact is there is zero suction/vacuum at the vacuum port on the tandem pump.

Thanks

Steven
 

usmcracing

Well-known member
Joined
May 19, 2008
Location
Sharpsburg, Ga
TDI
2006 Jetta BRM
Just wanted to update everyone on this. The tandem pump had seized and sheered the drive gear or whatever it's called. I removed the old tandem pump and replaced it with a new one. I noticed immediately that it was working, my brake pedal felt normal (actual better then it did before) and when I drove the car the turbo spooled up nicely.



 
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