Another newbie question: What is a Bosch Hammer and why is it so important for a shop to have one? I searched the FAQs and the history, and it seems that it has something to do with the the brakes. Could someone shed further light on this for me?

Thanks,
Paul

 

Dear Paul,
If you own a 964 C4 you must have access to a mechanic who has a full set of manuals and a Bosch 9288 or KTS500 tester and knows how to use it all.
You cannot bleed the brakes without all the above.
The Bosch Hammer is required for diagnostic work and is very important,
Ciao,
Adrian
911C4

 

When you say 'C4' does that mean that it is not necessary for a C2? Being a buyer of a C2, it would give me one less thing to worry about...

 

I think Bosch Hammer is a handheld (size of a laptop)instrumentation device that plugs to the car's electronics for diagnostic purpose. If anything goes wrong on a car, whether it be a sensor failure, or things out of adjustment the on board computer creates a log file and the Bosch Hammer is used to access the log file. The hammer saves the mechanics a lot of time locating the problem.

Mike

 

And by the way, I believe it applies to both C2 and C4s.

 

The Bosch hammer is highly recommended for the C2 especially when tracking faults in the DME, Aircon/Heating and other control units like the airbag etc. Without the Bosch hammer it can be very hard to track down control unit and sensor failures. The Hammer is not required for a normal brake bleed on a C2 but again it is recommended.
The Bosch Hammer is a "mandatory" requirement for the C4 even for basic servicing tasks on the brakes.
The Bosch Hammer is called a Hammer because that is what it looks like.
If you own a C2 or C4 and ask heavy duty questions about failures you have, you are more than likely going to be told to get a Bosch Hammer hooked up. Shotgun fault finding on a 964 series can get awful expensive,
Ciao,
Adrian
911C4

 

I think the going price for a Bosch 9288 or Bosch KTS 310 is about $3K US. YMMV.

jon

 

I am able to bleed brakes and change the fluid without a 'hammer', but it is difficult and probably requires a suction bleeder assist device ($40) which I have. I know there is another area on the C4 that requires bleeding (other than brakes)and does require the hammer to shift it open to drain. As far a bleeding in a pinch, it can be completed successfully without a hammer.

 

Hello

The brakeservice can be done without the Bosch hammer. The C$ needs the Bosch hammer to work on the tranysytem and all cars need the Hammer for the systemadaption.

The hammer will also speed up any regular work or trouble shooting. It also can check your ignition circuts and read out your fuel quality ( 10000 knocks ) and set the ECU to it, switches all lights, reads engine hours and all relatet parameter from accurate revs to resitance in each injector...............

It´s a basic tool making complicatet or impossible work simple.
Most can be done with workarounds but not all. The systemadaption is a basic work needed on all old engines as it adoptes the engine to the internal friction and volumetric efficiency and adjusts the parameters baseline to it.

Grüsse

 

Guys if you bleed your brakes without using a hammer on a C4 then you are seriously endangering your own safety and that of others. I do not care what you say, or claim to have achieved. The Porsche Manual is VERY clear, 8 pages of procedures and having seen the damage that can be caused to the C4 and the 928, you are taking risks that I cannot agree with.
Sorry about this but I have to stand up directly against those who suggest otherwise. This is very bad advice you are giving.
You can do anything you want. Is it safe to do so is another matter. In this case it is not safe. People have done it I know but think of this. You will never know unless you do the job properly if your brakes are going to play up. How about your Left rear brake applying itself at 200kph. Cause, bleeding without using the Bosch Hammer. 2 C4s and 1 928 I know of this happening on, all in the USA as well,
Ciao and good luck for those who ignore the procedures and of course know better.
Ciao,
Adrian
911C4

 

I should explain to all those interested WHY you must use a Bosch Hammer for a brake bleed on the C4. Some of you will know that the brake hydraulic system consists of the Brake System which uses a pressure pump and pressure accumulator, ABS circuit which includes a hydraulic control unit and the PDAS or traction control which uses hydro-mechanical locking devices. There is also around 23 meters, 60 feet of plumbing. The three systems all use the same brake fluid and pressure source. You are just bleeding the brakes you do not want to touch the rest of the system right. Okay, how do you know, even with power off, electrical and hydraulic that any of these systems are truly isolated. You are assuming not using the Bosch Hammer. The Bosch Hammer is used to ensure that ALL SOLENOID VALVES are shut and closed off. If when bleeding the brakes you have part of the rest of the system not 100% isolated (and you use a pressure bleeder system by the way) you will introduce air into the whole circuit and well, the results are well known when this happens. So not using the Bosch hammer you have no idea of the true status of the system before you start your bleed. This is a risky risky business. You are assuming.
If power (eloctrical) is applied the system opens ALL SOLENOID VALVES. So if you are bleeding without a hammer with the ignition turned on, guess what, you are not bleeding the brakes. The other reason you need a Bosch Hammer is to reset the fault codes from your brake bleeding activities, like setting the pressure switch off.
I could go on but I think that is enough,
Ciao,
Adrian
911C4

 

It's too bad Bosch doesn't make a Windows program that emulates the "Hammer" and let's you use your laptop and maybe a special serial cable adapter. Maybe some hacker will do this some day, it seems possible. I don't like the idea that there are no alternatives to the expensive and single-purpose "Hammer" tool.

 

when i did a search for "bosch hammer" on yahoo it came up with bosch rotary hammer drills. boy was i confused.

 

A former died hard 964 owner did try this and create a laptop based system. He came up a brickwall named Porsche who refuse to release the codes.
Ciao,
Adrian
911C4

 

I have laptop software that does most of what the hammer does. It can display values like idle speed and ignition advance. It will also read and clear diagnostic codes on the Motronic ECU, PDAS, air-bag and HVAC.

I spent a lot of time back-engineering the Bosch Motronic ECU on these cars so I was able to figure out how most of the diagnostics work on other components like the airbag and HVAC units.

The one thing I haven't figured out how to do is actuate the PDAS locks for bleeding. To figure this out, I'm going to have to back-engineer the code on the PDAS. I've already ruined one PDAS ECU in the process.

I've also not been able to locate a proper connector for the diagnostic plug.

-doug