Soft Clutch Pedal

eclipse
pump
clutches

#1

We have a 1997 Mitsubishi Eclipse with a hydraulic clutch. The pedal is very soft in the morning and requires a good bit of pumping the pedal to get good pressure. I know the system needs to be bled. Does this mean one of the cylinders is bad? I have added a little bit of fluid over the last year- maybe 2 or 3 ounces total. Right now the fluid level seems fine but it still needs to be pumped before driving.


#2

It means you have a leak somewhere. You shouldn’t have to add fluid. Hydro clutches and brakes do not consume fluid, so if the fluid goes down, it’s leaking out somewhere.


#3

I guess it’s a pretty slow leak- maybe bleeding it will help for a while- Otherwise I guess one or both of the cylinders should be replaced.


#4

It very well could be a slow leak, and I would hazard a guess and say it’s by the master cylinder. If you can “pump it up” and get it to work, then it’s not holding the fluid like it should, and you’re getting air into the master. Pumping it will gradually move the air around, replace it with fluid, and then it will work, although it will most likely still be squishy.

Has the fluid in the system ever been drained/refilled (or replaced, as it were)? After 15 years, it’s pretty old if it hasn’t, and likely to be a part of the problem.

Chase


#5

I had a guy bleed the system- He said he could not find any leaks. So far it is working well.


#6

It’s a good idea to change the brake and clutch fluid every 3 years.
Hydraulic components will last much longer.


#7

If the problem returns replace both the master and slave cylinders. I have never replaced one without the other failing within 90 days.


#8

Agree with Rod. Replacing a master without changing the slave or vice versa is just asking for trouble.