asbi

All,
Had my brakes fluid changed a few weeks ago for Castrol SRF race fluid.

Intially the pedal felt nice and firm. I then parked the car in my garage for a oouple of weeks and on driving the car again noticed that the pedal felt softer than before the change.

The brakes work fine on track and I can lock up the front wheels before I get to the bottom of the travel but I dont like the spongey feel of the pedal.

The car is going back into the shop this week (well known local 911 specialist in the UK), what should I be asking them to check? As my car is an RS it uses the C4 pressurised braking system.

If there is some air in the system would it be in the actual braking circuit or the pressure assist curcuit? Also I wonder why it was OK when I picked it up but then went "spongey" after having been stood for a couple of weeks?

Thanks in advance for any help,
Kevin.

Geoffrey

You may also have a wheel bearing going bad which will push the pistons of the caliper back and cause a spongy pedal.

elbeee964

Brake hoses? They are getting on 15 years old, if stock. Their slight bulging would feel that way, too.

Pull the pads to see if the caliper seals have distorted unusually/nonuniformly? (long shot odds)

Guess after bleeding, my nose heads straight for the elastomer constituents. Rubber items, first.

boxsey911

Did you bleed the clutch slave at the same time? There's a fair bit of fluid in the hose to the slave. Makes me wonder if old Dot4 in the clutch lines/slave has slowly mixed in with your new SRF.