The Bus

I've switched my C4 to C5 calipers/rotors. Front only. It takes almost the entire stroke of the pedal to have a hard pedal/brakes. If I pump them once it is a full pedal like the C4 calipers are with just one push of the brake. The first thing that I suspected was air in the system. Bleed it at least 5 times. Switched back to C4 caliper/rotors and everything is back to normal. Put C5 parts back on [ bleed 3 times ] and same problem. I assume the additional pedal movenment is due to the additional C5 caliper volume?? Problem is ?????? Due all brake boosters have adjustable push rods?? If I extended the push rod an additional amount [ length not yet determined ] will that do the trick??? Or am I missing something?? If so what do I need to do to correct this problem since I know that others have done this???

THANKS FOR ALL SUGGESTIONS/HELP and I do mean HELP.

jaa1992

do a search in the c4 tech section.
I'm sorta remembering some folks had to go to a bigger master.

Aardwolf

I adjusted the push rod on mine and the system is working well. IIRC I left 1/16" gap between the rod and M/C cup. I used a bent piece of metal to measure. Hold the nut and turn the push rod from what I remember.

On long straights I still have to double pump, due to pad knock back.

jwt1603

I didn't have to change / adjust anything when I converted to C5 fronts. I know several people that switched with no issues. Are all the parts new?

mikemiller68gs

I also made this change on my C4 and had no issues. i wonder if the issue is with your calipers. Did you use new brake hoses?

c4cruiser

What year is your car?? Were the OEM front calipers single or dual piston?

When I installed C5 front brakes on my 87, I noticed a very slight difference in pedal travel but the upgrade worked fine. I also installed the Doug Rippie brake bias spring and that didn't change pedal feel at all.

The Bus

If the calipers aren't leaking what could be wrong with them??? Not saying your wrong just asking???

Sidney004

If the calipers were raced( and cooked) or the calipers you bought were used and had been raced, they could of spread; which would give you a long pedal.

The Bus

Never thought of that. I have a new set of calipers I'll try.

THANKS