Rick Lee

I haven't DIY'ed a brake flush on my 993 since before I wrecked it in October 2004. It was last done in April '05 when the shop had it for engine install. I do this all the time in my SC, but can't remember some things about the 993. Is there a trick to cycling the ABS while doing a flush? How? Also, since the SC has a cable clutch, I forget the procedure for bleeding a hydraulic clutch with a Motive bleeder. Can I just open the slave bleeder screw with the Motive pressurized and also pump the pedal? I pump the brake pedal all the time when I use the Motive on my SC. This is safe with a hydraulic clutch, right?

Don Plumley

Yup - motive bleeder works great with the hydraulic clutch. In theory you could pump the clutch pedal half-way, but I don't think it would be necessary.

About the abs - I have no idea and am eager to hear an answer. Short of having a Bosch Hammer, I don't think there is any way to trigger it. For grins, I powered my car on and off a couple of times in case something in there cycled....

AOW162435

Rick,
I used the Motive with great success for both systems. I did not cycle anything or touch the clutch pedal. Simply kept the reservoir full and bled in the standard sequence. I only use the Motive for pressure - not as a holding tank for the fluid.

I've read of other methods on Rennlist, but this has worked for me more than once on the 993.

Andreas

Robin 993DX

Nothing special to do with the ABS when flushing, as long as you don't have air in the ABS system, or some how got air in the master cylinder. So make sure you monitor the reservoir fluid level as you flush the system. When you get air in the ABS system no matter how mucn you flush, it will not help. There is only two known way to flush out air trapped in the ABS systems (1). Flush it in conjunction with the Hammer unit to activate the ABS unit while it is flushing. (2). Go out in an empty parking lot and try to get the ABS to fire off and then flush it right away until all the trap air is out of the system.

As for the clutch fluid, flush it at the clutch slave cylinder end with the clutch pedal depressed. So basically find a bar or something to hold it in place.

blackcat

What sort of behavior would the ABS exhibit if there were air in its system? My ABS is acting funny - when I brake hard enough to activate the ABS, I get a jerk to the right and uneven action by the calipers... not the usual rapid ABS feel - it's slower and it causes very brief lockups... any idea what could be causing it?

tia

Rick Lee

Well, I haven't used anything but ATE Blue in so long, so I'm gonna out two cans of ATE Gold in the Motive this time and get all the old blue stuff out.