Surging problem again
Thread Starter
Intermediate
Joined: Jun 2010
Posts: 27
Likes: 0
Surging problem again
Hi there,
Independant garage seems to think that my surging problem may be the brake servo or pipework leaking. I cant see where the brake servo is.
Any tips on testing the servo line, and where the servo non return valve is. Car is a 95 993 with OBD1 which once again has shown no codes apart from 45, check engine light.
Thanks everyone, you must be getting sick of me and this fault!
Mart
Independant garage seems to think that my surging problem may be the brake servo or pipework leaking. I cant see where the brake servo is.
Any tips on testing the servo line, and where the servo non return valve is. Car is a 95 993 with OBD1 which once again has shown no codes apart from 45, check engine light.
Thanks everyone, you must be getting sick of me and this fault!
Mart
Rennlist Member
Joined: Nov 2002
Posts: 12,229
Likes: 103
From: Chicago
Is he referring to the hose that goes from the intake forward to the brake vacuum assist cylinder?
But the bigger question: have you checked for intake leaks? I.e. remove the airbox, buy a rubber pipe cap from Home Depot, and pressurize the system (air compressor is needed) to like 15 psi. It should take like 10 seconds to drop to 0. Air escapes thru the resonance flap actuator, but shouldn't leak anywhere else.
But the bigger question: have you checked for intake leaks? I.e. remove the airbox, buy a rubber pipe cap from Home Depot, and pressurize the system (air compressor is needed) to like 15 psi. It should take like 10 seconds to drop to 0. Air escapes thru the resonance flap actuator, but shouldn't leak anywhere else.
Thread Starter
Intermediate
Joined: Jun 2010
Posts: 27
Likes: 0
HI TheOtherEric,
Yes, its the hose that goes to the brake vacuum assist. I have checked very carefully for intake leaks, but I think that your idea to pressurise the system would be well worthwhile. I will have a go at this over the weekend. Cant see where the servo pipes and servo go though! I cant help but think that this fault is something small that is having a big effect. If it was the ECU, coils etc, surely the car would run fairly rubbish more that the 5 to 10 seconds after a start. Once over the surging, the car is absolutely spot on, returns from 18 to 30 MPG depending on how much I press the loud pedal, uses little oil (more 993 usual leaks!) and really makes me smile!
Mart
Yes, its the hose that goes to the brake vacuum assist. I have checked very carefully for intake leaks, but I think that your idea to pressurise the system would be well worthwhile. I will have a go at this over the weekend. Cant see where the servo pipes and servo go though! I cant help but think that this fault is something small that is having a big effect. If it was the ECU, coils etc, surely the car would run fairly rubbish more that the 5 to 10 seconds after a start. Once over the surging, the car is absolutely spot on, returns from 18 to 30 MPG depending on how much I press the loud pedal, uses little oil (more 993 usual leaks!) and really makes me smile!
Mart