Brake Booster Adjustment?
 

Sorry for the ignorance but I have a question that I am hoping someone knows the answer to. On our 99 Boxster the brakes got very hard to push all of a sudden one day. Since the car is still covered under warranty we took it in to have it repaired. My feelings are that the brake booster failed. The story we were given was that the brakes needed an adjustment before they could determine if the booster was bad. They said the booster would be covered under warranty but the adjustment would not. Price for the adjustment $600.00.
Now I have done a number of complete brake overhauls on my BMW's over the years including the hydraulic assisted system on my 535 and this just doesn't sound right to me. Does anyone know what this adjustment may be and what would be involved in doing it. Additionally, it seems to me that if it were an adjustment it would have been a progressive problem not one that happened suddenly. Any help or opinions on this matter would be appreciated. Thanks.

Hi,

I don't see anything in the Manual about Testing or Adjusting except for checking the Unit for, and resetting, any faults with the PST2. Sounds like a bunch of Bull to me. Although to be fair, the Liability incurred with a Brake Job would make this prudent for a Mechanic to do.

You also want to eliminate the ABS Hydraulic Control Unit (w/ integral Pump)as a possible cause/contributor to the issue. I would have them explain exactly what they're checking or adjusting. A significant change was made to later cars w/ PSM/TC so you want to be sure they're not confused with your specific model.

One easy way to check the booster is to depress the Brake Pedal several times all the way to drain the Vacuum stored in the Booster, then hold the Pedal all the way down. Start the Car, holding the Pedal down, and you should get some near-instant feedback through the Pedal once the Booster energizes. The Pedal should actually apply even harder.

Removal and reinstallation are very straightforward, but you'll also have to Bleed both the Brakes and the Clutch when your finished. On a '99, depending upon the mileage, you might as well consider replacing the Master while you're in there (simple step since you need to remove it anyway to replace the Booster), because a New Booster will lead to failure of a used and worn Master.

I checked the price of the Booster (P/N #996 355 923 00) in ********************************************'s Catalogue and they list it at $301.00 and the Master (P/N #996 355 910 00) at $347 (subject to verification, and maybe cheaper elsewhere).

So, if you're confident that this is the problem, and you sound adept enough, you might forego the Warranty Claim and the $600+ Adjustment and do the work yourself. I know it's a ********************ty Deal, but it seems nonesense to spend $600 to get a free $300 Booster. Hope this helps...

Happy Motoring!... Jim'99

I would specifically ask the service manager what exactly it is they are adjusting, other than maybe bleeding the brakes.