Clutch master cylinder: Fluid does not come out like suppose to

[2gspider]

Hi guys,

Yesterday i have this weird issue with my clutch master cylinder, so I hope someone has some inside or advice. I know this is extremely long description, but i think it's necessarity to explain the situation.

Ok, my old clutch master cylinder leaked, so i replace it with a new OEM mitsu one, about a year a go. Also replace the slave cylinder as well. However, the clutch pedal never felt right, it always have a crunch noise when pedal almost all the way down. I bleed it quite a few times, but keep getting sprongy. I tried to adjust it following few tutorial, to prevent pump up issue. Anyway, i decided to take out the master cylinder to inspect, and everything seemed ok.

When i took out the MC from the car, i pressed the rod in to test for smoothness and it felt allright. I tried to put some water in the reservior and press the rod in, the water shoot out of the open hole (where the clutch hard line connects to). So I thought everything is ok, and decide to put it back in the car. Ok, this is where the weird thing happended. I filled the resevoir with brake fluid, and connect the hardline to the MC, but the brake fluid doesn't seems to come out of the top opening like it suppose to. I also took the hardline out, have another person pump the clutch and still i see no fluid shoot out of the "hole", clutch reservoir still full. it almost like the CM doesn't suck the brake fluid down or some reason.

 

[Defiant]

You put water in it?

Throw it away.

 

[2gspider]

I guessed that's a bad thing . Can you tell me why? I was just testing it when i had it out of the car.

 

[4g63owns]

Did you make sure you bled the system right when you were done? Also, why didnt you just use brake fluid to "test" it? putting water where oil goes is always a no-no

 

[Defiant]

Brake fluid is hygroscopic- it absorbs moisture. Contaminating the seals and passages with water essentially ends the train ride. You may be able to flush it with alcohol and a lot of brake fluid, but by the time you're done you'll have spent the cost of a new cylinder. And it is just the brakes. Some think such systems shouldn't be half-assed.
Your mileage is determined by your foot.

 

[2gspider]

Thanks for the explaination.

Yesterday, after many pushes on the clutch MC rod, fluid finally shoot out of the openning like it should (lucky). i'm going to bench bleed it first before install it back into the car. I wished i had kept the cover for the top hole of the MC to keep the fluid from dripping.

Also quick question, when i bleed, do i have to put the cover back on the clutch reservior after each refill or i can leave the cap open during the bleeding process? I don't think the air gonna suck into the resevior since the brakefluid should prevent air from entering, unless fluid level is low.

 

[snowborder714]

You can leave the cap off as long as you monitor the fluid level and keep it full.