pulsating break pedal

[Big Vern]

Hi,

please can anyone help
i have recently had some brake work done to my transporter 1.9dg petrol 1990.

new rear brake drums as one was distorted( break shoes ok)
new front pads ( did not replace the disks )

since this work i have a pulsating break pedal , not all time though and the van stops ok.
has anyonre any idea how to cure this?
will it gets worse if left

This club is really cool and its members are really very helpfull to (no nothings like me)
much appreciation in advance.

Big Vern

[jamesc76]

If its pulsing I'd recon on front disc warped???

[T'Onion]

if you reused the rear shoes then it could be them

[lloyd]

As James says, probably warped rotor, but is possible to warped drum. Might try loosening and re-torquing lug nuts as can sometimes cause this.

E D I T: And Mark too.

[ghost123uk]

If its pulsing I'd recon on front disc warped???

Yep, this is the usual cause of your pulsing brake pedal (note the spelling of "Brake" btw )

Last time I needed disks (for our Scirocco) they were silly cheap at the VW main dealers !!
Note = if trying the dealers you will likely need to find a "VW Van Centre", not the VW car spares ones. Otherwise I would recommend Brickwerks or EuroCarParts.

btw - if interested, the often quoted cause of warped disks is coming to a standstill after braking from speed, then sitting at the junction etc with your foot on the brakes. It causes a "hot spot" were the pads are contacting the disk and the uneven temperature causes warps.
Moral = after prolonged use of brakes, then standing still, use the handbrake

[Fritz]

The question is: was the pedal pulsing before you had it looked at ?



My guess is ,,,,,,,as follows...
I have had this problem after similar work done by my good self,,,sometimes if the rear drums are not centralised fully or the drum screw has not been re fitted then then brake pedal may pulsate....

and seeing as this is the last bit of work done I would be asking them (the garage who did the work) to check that they have been put back on properly.


Regards,


Fritz,,,,,,,,,,,

[Red Westie]

Now to diagnostics:
Front discs warped = creates a pulsating brake pedal WITH a violent shuddering through the steering wheel (only when braking)

Where as

Rear drums = JUST the pulsating pedal (no steering shudder)

Now you have determined front or rear, how do you determine which side is faulty (it may be both of course but often it's just one)

WARNING* this has to be done with care as you will be creating a brake inballance (fairly safe when done to the rears) but not the fronts as the steering will pull abruptly one way**

By using a brake clamp (girling or similar) clamp off one side flexible hose and road test....if the pulsating goes then you know it's that side
Warning* don't over tighten the clamp.
Martin

[Red Westie]

As for centralising the drums and the retaining bolt:
The retaining bolt serves no other purpose other than holding the drum in the correct place whilst assembling, it can be and often is, left off.
As for centralising: as long as the hub was clean and free from rust the wheels serve to clamp the drums in place....no centralising.....
Martin

[kit]

Dont forget your 89 90 discount at GFS.

[Mr Bean]

I can't believe anyone would do this but if they skimmed it on a lathe without centering it correctly thaat is just what you would get. Unless of course they just kept the brakes on too long on the rolling road and verheated the drum. Get them to fix it under warranty. Or just find yourself a better garage. Drums and disks are cheap as chips - comparitivelly.
Cheers
Wolfie
(One of my work colegues bought a brand new Boxter which had a clutch pedal that went up and down like that and they said it was an endemic fault common with dual mass flywheels. Even rich people get problems like that!)