Good day. I recently changed the rear disk brake pads on a 2005 F150. I did as I have always done in the past, that is to use a common 'C-clamp' to bottom out the disk brake pistons in their respective calipers prior to installing the new brake pads.

Now I have done countless brake changes, but mostly on the older, non-ABS equipped vehicles. I've been told that using a 'C-clamp' to bottom out the caliper pistons on an ABS equipped vehicle can damage the ABS system. This is the first that I've heard of this.

I would like to ask if this is indeed the case. Can forcing the brake fluid 'back-wards' in an ABS system actually cause damage?

I was told that you need to crack open a bleeder screw on the respective caliper before bottoming out the brake piston. What can you all tell me about this???

 

I think I've found the answer to my own question so I thought that I'd pass it along...

Ford Repair: spongy brakes after pad and shoe replacement, 2001 mercury sable, spongy brakes

 

I suppose it's possible, but I've never ever had a problem pushing the caliper back in an ABS vehicle w/o opening the bleeders or anything. Never heard of that either, but I can see how it could be possible. Maybe.

 

The trick to the brake job is before you compress the piston's is to loosen the brake filler cap so the back pressure doesnt push the other side out. and out of the 100 or so brake jobs on trucks that i have done it doesnt mess with the ABS... in fact the only time compressing caliper piston's is a problem is with the escape's that are hybrids with regenerative braking, (what a pain!!!) my advise is to find out what code you have and go from there. As a side note I highly recomend seeking out a reputable garage to perform a brake fluid flush, reason is due to the high cost of ABS brake componits it replaces the fluid and keeps it in good working order. i do it on my own cars every 3 years. with time on your side you can shop around for the best price, good luck

 

Sincerely thanks for the replies, there's lots of good info there. Reference doing a brake flush, couldn't that be easily done by the owner? From what I've been reading (somewhere else on this forum), the only difference between flushing/bleeding an ABS system vs a conventional brake system is the need for a code scanner to be attached to the truck's serial data port.

Apparently the scanner is required to activate the HCU (ABS module) to ensure that the unit is properly flushed. In any case, the truck's owner is concerned about a 'spongy' brake pedal. I am guessing the the rear pads have not bedded in yet. AFAIK, there are no ABS codes or lights showing...

 

Well with regaurds to the flushing what we do at the dealership is to connect a cap to the brake filler cap hole and it pressurizes the entire system then we crack open each line and allow the old out and the new fluid in. With this machine we dont have to bleed the HCU, it is one of the best flushers we use beside the transmission flusher. We the industry should have had this stuff years ago.