Clutch Pedal to the Floor, Master Cyl nr Full


#1

Hi again,

Toyota 1995 T100 base model 4 Cylinder Std cab 2WD.

So the clutch pedal has been going down to the floor but I have been able to get my toes under it and pull it back up. But today, the pedal has much less resistance and goes even further - harder to get any leverage with toes to bring it back up.

Checked the master cylinder and it was near the low line, so there is plenty of fluid. But I topped it up - about 1 oz. At first, the pedal had some resistance as I pumped it without starting the truck. Fifteen minutes later, I was going to test drive it but the pedal went back to the floor easily. Fluid at the high mark now.

So if there isn’t leakage out of the system, is it most likely failed master or slave cylinder? What is in a “master cylinder repair kit”?

Bardi


#2

The clutch master cylinder is leaking internally. If the slave cylinder were leaking there would hydraulic fluid leaking onto the ground.

Don’t bother rebuilding the master cylinder. Just purchase a replacement master cylinder. And might as well replace the slave cylinder too. Because if the master cylinder is leaking, the slave cylinder isn’t far behind.

Tester


#3

Failed MC. The fluid is staying in the NC chamber, but the fluid is passing right by the piston that’s supposed to transfer the force to the slave cylinder.

Replace the master cylinder and the slave cylinder both. Otherwise, you’ll just find yourself replacing the slave cylinder very shortly after you replace the master cylinder.


#4

I was thinking the same thing. As well, I’d let the fluid drain and replace with new - it’s black! Is it worth shooting brake cleaner through the lines? Or is that a bad idea?

What about brand? I see AISIN, Beck-Arnley, Sachs, Bendix, Centric, PBR & Dorman. Am leaning toward AISIN, but welcome feedback. Toyota prices are about 2-4x higher than these “Direct Fit” brands.

Bardi


#5

Bad idea IMHO. Flush them with some ATF to clean them.

Any of the “direct fit” aftermarket parts will be as good as the dealers, you just won’t have to pay to support the dealer’s distribution system.


#6

Tester I was surprised by the low price of new master cylinders. My 1991 Mazda RX7 was leaking from the reservoir conical gaskets. They were unobtainable. Mazda wanted nearly $200 for a new master cylinder (no surprise). I purchased a new master cylinder from Rock Auto for less than $40 including shipping. It worked fine.


#7

"Flush them with some ATF to clean them. "

He meant flush with brake fluid.


#8

AISIN from RockAuto lists a 1 year warranty and there were a few positive comments. So I went with them.

Will post some pics when I replace them.

Thanks for the feedback & guidance.


#9

The master cylinder looked & felt OK. Smooth action and the spring pushed back. But it probably was leaking inside.

The slave was definitely FUBAR. After pulling it and taking off the boot, it was rusted inside and was not springing back. But no sign of fluid leakage.

I replaced both; about $65 for both with shipping from RockAuto.com. Pic attached.

Did not want to get brake fluid or even traces on my phone, so I cleaned up without taking pics. It was all I could do to keep from cursing with the neighbors’ kids nearby as the replacement went on.

Test drive - all OK. Wonder if the slight slippage in 2nd & 4th gears will go away?!