Cadillac CTS First Generation Forum - 2003 - 2007 Discussion, ABS Brake System Flush Question in Cadillac CTS Coupe, Sport Sedan and Sport Wagon Forums; Hi all,
I have a 2004 3.6 L CTS with standard suspension package that I plan to flush and replace ...
I have a 2004 3.6 L CTS with standard suspension package that I plan to flush and replace the brake fluid very soon. I have already read the CTS shop manual (invested the $150 to get the 3 volume factory books) and searched the internet, but I have come to know that this forum has some very knowledgable members, so I need to ask you guys:
Q: The shop manual does not make mention of needing a scan tool to cycle the valves in the ABS system while flushing the brake fluid. Does anyone know if the 2004 3.6L with standard suspension uses either the Bosch or Delphi ABS systems that have the hidden passages that require the scan tool to activate it while doing the flush procedure, or can I simply follow the traditional flush procedure that is outlined in the shop manual?
I plan on doing the flush next weekend. Thanks in advance for your answers!
No need for a scan tool to activate the ABS pump when flushing the brake system. The only time you need to control the ABS pump is when to have air in the system and need to bleed it. When flushing the brake system there is a machine that feeds brake fluid into the reservoir, while the pump pulls the old brake fluid out of the bleeders. If your going to do it yourself have someone fill the reservoir with a bottle of brake fluid and open the bleeders one at a time starting with the RR then, LR, RF, and ending with the LF.
I should have mentioned that I will be bleeding the system myself with the help of a Motive power bleed system. I know from my knowledge of some German cars that if the ABS system is the Bosch ABS 5.3 or 5.7 system or the Delphi DBC7, that the internal valves stay closed and the scan tool is needed to reposition the valves to the "home" position so that the ABS unit gets new brake fluid also. I don't know what type of ABS system the 2004 CTS uses.
As I mentioned, the shop manual does not mention anything about the ABS when bleeding the brakes, so I am assuming the traditional bleed procedure should be enough. Just wanted to check in here at Cadilac Owners.com first to get the straight scoop.
Wait what? A brake system has their system stay closed when powered off? So what happens in a panic situation you lose power, therefore the ABS does too, and you have to brake? Then what, with the valves on the ABS closed, you basically have no brakes. At least that is my thought on how that system works.
In my research I discovered that when the car is in park and not running, some ABS systems return the valves to a "home" position so that the system is "open". The earlier mentioned Bosch and Delphi systems do not return the ABS unit valves to "home" without a scan tool. So, I read that those systems will close off and old brake fluid will stay in the unit and not allow new, fresh brake fluid to flow through if you are bleeding the system. Since I did not see a scan tool requirement or procedure mentioned in the shop manual, I am assuming the ABS system on my 2004 automatically puts the ABS unit valves in their home position when the car is in park and turned off, thus allowing the fluid system to be open and all fluid flushed out.