Lack of power and overheating brakes but no binding etc? related..

[Zaac]

I'll try to keep this as simple as possible...

Today on my way home from work i experienced what can only be described as HORRIBLE turbo lag 2100 rpm before anything happened. whereas normally 16-1700 rpm it's taken off and blasted a scooby (its a 1.9tdi 130pd mapped upto 170)

So i thought ok i'll look at it when i get home. Rang the AA because i've got the full cover for garage labour parts etc and he couldn't find anything i went out and blasted it to see if it needed a clear out or to see if it flatted off or blew up or whatever but nothing? The car felt weird under braking so i went upto 70mph and broke firmly, to my suprise not much effort? So i went back to 70 and jammed on and there was very little effort and when i eventually stopped the brakes were pouring with smoke and stunk of burning but there is no binding rolls freely and all wheels move freely?? AA come back out and are completely stumped... It's now booked in to my local garage on Thursday but i want to find out if anyone has any experience of this and can help me before i have a bit more knowledge before i go to the garage...

There's also a flatspot around 2-3k can be anywhere the chap from the AA said possibly the brake are slowly actioning and every now and again snatching a little bit like the servo is pushing the brakes and then causing what feels like a flatspot. But driving normally and braking normally it's perfectly fine and when on boost if im in 4th at 70 and floor it sometimes it's dead like theres nothing there but other times it will take off so im thinking some sort of vacuum?

Either the 2 are related or completely seperate but it all came on at the same time!

Hopefully someone can help.

 

[Jama665]

Actually sounds similar to what I have now, be interested to know if you manage to find the problem before me what it is. Nearly layed a brick the other day went to stop quick and hardly anything. Stood on the pedal and it colapsed to the flood with the abs kicking in with no locking up. Brakes where smoking hot. Was almost like having massive brake fade. Also experiencing lag at gear changes to.

 

[Zaac]

I've just read this.

Hi Stefan,

I've no idea if this helps, and I have the 130 BHP version 5 speed, on a 52 reg, so slightly different setup but for the past 2 years I've suffered bad fuel consumption, I had it serviced, no difference? was only doing 485 miles on a full tank of fuel, compared to the original 650 it used to consistently do. No faults appeared on VCDS scans, engine all running fine?

Only thing I noticed was it burned out a set of front brake pads in about a year 8 - 10k miles. The garage said the front caliper had stuck on, great cost for a new caliper, pads and discs. Even after it was done, I thought the front left side always ran hotter than the right. 9 months later, another set of brake pads burned out only on the front left. This time garage replaced brake master cylinder and servo. Overnight difference, Fuel economy back to 600 plus miles on a tank of fuel.

Garage said the brake master fault was quite common on the 2002 - 2003 age cars.

Not sure if it's the same problem on your car, but might be worth seeing if your front left wheel is hot?

The only thing that makes no sense, is why all the brakes did not stick, I don't know why it only affected the front left?

Paul


This sound exactly the same as our issue but nothing to do with power issue? Unless the brake is sticking whilst running

 

[Jama665]

That sounds encouraging haha. Hope its not the servo tho. Mines a 1.8t so the brake issue must be a model related problem mines also a 2002. How does a trouble some servo allow the brakes to come on i'm wondering. Obviously the faster you push it the more it's effected. Weird one this

 

[Zaac]

It must be forcing the brake to engage slightly or just enough to warm the pads and then cook them when you brake... just a guess

 

[AlexGSi2000]

Boost and brakes - vacuum related?

I know the brake servo is vacuum assisted (taken from the inlet manifold if I remember correctly)
The actuator on the turbo is also actuated by vacuum.
This could be what is causing issues with both?

Check all vac lines, including the one from the servo.

 

[AudiLeon]

My money would be on the nipple that goes into the vacuum pump.
On our A6 is had worked very loose and was losing vacuum.
I swaged over the connections and used some sealant and it's been great since.

 

[audilad9]

Reading all this with interest, my brakes are shocking, the pedal goes to the floor if you keep pushing it and the abs engages. Pumping the pedal makes it firm again, far from ideal ! No fluid loss anywhere, and no noticeable drop in boost, but economy is poor. Hoping master cylinder/servo replacement is avoidable, so will recheck all vac pipes.

 

[Zaac]

I've now worked out if i accelerate hard through the gears by the time i get to 80 it;s burning and the brakes are ******? and no pedal!?

 

[krisavant]

I've now worked out if i accelerate hard through the gears by the time i get to 80 it;s burning and the brakes are ******? and no pedal!?

No pedal will be brake fade cause they're so hot.

 

[desertstorm]

I had a similar issue to this many many years ago with a Ford Capri. The brakes would be sticking on and dragging during niormal driving but try and accelerate hard it would exaggerate the problem. In the end I went to the breakers yard and bought a servo and master cylinder and swapped them both over. Fixed the problem.
I think it's a vacuum leak on the servo, If the seals leak they can let air into the servo which will partially cause the brakes to drag. more vacuum will cause more dragging.

Power Brakes - Vacuum Assist - Explained - YouTube

Karl