Polo tdi sportline brakes not braking hard enough

Post Reply
Showi
Enlisted
Posts: 4
Registered for: 3 years 1 month

Polo tdi sportline brakes not braking hard enough

Post by Showi »

Hi all, so I recently got a sportline polo tdi, my issue is that when I apply the brakes, the car will come to a stop but the brakes only work to a certain extent, so for instance when I am approaching a speed bump at a speed, I can initially slow down but as I try press the brakes harder as I get closer, the car will not brake further and the pedal seems to get hard and just won't go past a certain level. The car generally stops well its just when I am coming a little quick and I have to press the brakes for a longer period of time and try to apply more pressure as I get to the stop point that the pedal goes harder and the car struggles to come to a 'emergency stop'

Brake pads and disks are still good.

What could be the issue here?

Thanks in advance for any help and feedback provided!
Callum229
Cadet
Posts: 251
Registered for: 4 years 1 month
Car Make: VW
Car Model: Jetta MK5 TDI DSG Highline
Location: Durban
Contact:

Re: Polo tdi sportline brakes not braking hard enough

Post by Callum229 »

Check on the back of your Tandem/Vacuum Pump, there is a pipe that comes out.

The tandem pump is on the side of the engine block on the passenger side. There is a nipple towards the top of it on the back, it is connected with a plastic pipe that is known for cracking and breaking, thus leaking vacuum and making the brakes hard to press.

Inspect the lines carefully and make sure there isn't any cracks or leaks.

If that checks out fine, check brake fluid level and maybe bleed the brakes, you might have some air or just old, contaminated brake fluid.

If that's fine, then you most probably have a leaking seal on the brake servo or something more serious.

Please see the photo, the black nipple on my pump is where the vacuum line connects for the brakes. It could also be metal but it's around that height, at the back of the engine on the RHS of the head.Image

Sent from my Nokia 8 Sirocco using Tapatalk

2007 VW Jetta MK5 1.9 TDI DSG,

Mods: Simple EGR delete, LED interior set up, LED rear footwell lights, LED Puddle lamps, LED Doorhandle illumination, LED License plate lights, LED Boot lighting.

2007 VW Golf 5 1.9 TDI DSG, no mods.

2007 VW Transporter 2.5 TDI 4motion, no mods.
MSD
Wheel Whore
Posts: 49
Registered for: 6 years 6 months

Re: Polo tdi sportline brakes not braking hard enough

Post by MSD »

I have the same issue and i still cant find the fault. the system is sucking air instead of creating vacuum.

When on idle try pumping the brake and see if there is a change in the feel of the pedal. The rev should increase slightly and the turbo should start spooling. When this happens the brakes will not go as close to the floor and the pedal should feel as if the vacuum is assisting.

Most probably a hose that is sucking air. Seems like a common fault. You can use a vacuum meter to test for leaks.

Post your findings. Interested to find out where your fault is.
User avatar
Morné Pieters
Cadet
Posts: 546
Registered for: 9 years
Car Make: VW & Mercedes-Benz
Car Model: 07 1.9TDi & 09 C350 CDi
Location: Pretoria, South Africa

Re: Polo tdi sportline brakes not braking hard enough

Post by Morné Pieters »

You need to follow the big plastic pipe that sucks vacuum from the tandem pump. Normally, at the plastic fittings, the plastic pipe splits and sucks air. This normally happens at the brake servo connection fitting or the one way valve or the tandem pump connection.

I hope you managed to resolve your issues :hi:
Image
2007 White Polo 9N3 1.9 TDi (PD100) - Daily Ride (Odo 306 000 km)
PD160 Intake lPD130 Intake System lEGR Blank lPD130 Turbo lDe-Cat lStraight Flow FMIC (450x230x65 mm) & 50 mm S/S Boost Pipes lWulfchip Software lFK Projector Headlights & 6000K HID lLED Retrofit lCustom LED Footwell Lighting lCustom Leather Interior lGTI Black Interior lCustom Speedo Cluster lCruise Control
Post Reply